I N S I D E From the editor From the coordinator Obituary - General - Ticks - Tick-borne diseases - Piroplasmosis - Theilerioses - Babesioses - Anaplasmosis - Ehrlichioses - Cowdriosis - Other diseases - Announcements Addresses of the editors 39 From the Coordinator Frans Jongejan I am glad to be able to announce that the ICTTD Coordination Action Project has been extended for another year until the end of August 2010. The extension gives us the opportunity to collate and disseminate the large number of project deliverables and also creates sufficient time to finalize all administrative matters. Good news also for the readers of this Newsletter, since we will be able to continue this publication. I apologize for the late arrival of this issue and for the lack of illustrations. The cover illustration shows an engorged female Dermacentor reticu- latus female tick fed to repletion on an artificial membrane here at the Utrecht Centre for Tick-borne Diseases (UCTD). A good example of success- ful ICTTD information exchange and collaboration between members of the coordination action facilitated by the team of Patrick Guerin at Neuchatel, who demonstrated in an ICTTD- funded workshop how to go about the in vitro feeding of Ixodes ricinus. As a result, the in vitro feeding methods appear to work for a broader range of ixodid tick species. N E W SL E TTER ON TICKS AND TICK- BORNE DIS E A SES OF LIVESTO C K IN T H E TR O PIC S J U N E 2 0 0 9 ICTTD PROJECT EXTENSION APPROVED FROM THE EDITOR Gerrit Uilenberg Looking over old documents I was reminded once again that an isolated sci- entific experi- ment often can- not lead directly to a definite answer. Nothing new of course, but it does no harm to keep in mind once more the value and shortcomings of statistics in science. Conclusions from experimental results are very often based on statis- tics, and can then only indicate a degree of probability, never an abso- lute truth. For example if a certain drug appears to be effective in an experiment, the efficacy of the treat- ment is considered statistically sig- nificant if there is a 95% of probabil- ity that it is not due to chance. This means that there is a 5% probability See page 2 2 6 8 14 15 16 21 25 29 30 29 ICTTD-3 1 1 1 In vitro feeding and photo- graph by Anne Marie Rhebergen (Utrecht Centre for Tick-borne Diseases (UCTD) 31 32
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I N S I D E From the editor From the coordinator Obituary - General - Ticks - Tick-borne diseases - Piroplasmosis - Theilerioses - Babesioses - Anaplasmosis - Ehrlichioses - Cowdriosis - Other diseases - Announcements Addresses of the editors
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From the Coordinator
Frans Jongejan
I am glad to be able to announce that the ICTTD Coordination Action Project has been extended for another year until the end of August 2010. The extension gives us the opportunity to collate and disseminate the large number of project deliverables and also creates sufficient time to finalize all administrative matters.Good news also for the readers of this Newsletter, since we will be able to continue this publication. I apologize
for the late arrival of this issue and for the lack of illustrations.
The cover illustration shows an engorg ed female Dermacentor reticu-latus female tick fed to repletion on an artificial membrane here at the Utrecht Centre for Tick-borne Diseases (UCTD). A good example of success-ful ICTTD information exchange and collaboration between members of the coordination action facilitated by the team of Patrick Guerin at Neuchatel, who demonstrated in an ICTTD-funded workshop how to go about the in vitro feeding of Ixodes ricinus. As a result, the in vitro feeding methods appear to work for a broader range of ixodid tick species.
NEWSLETTER ON TICKS AND TICK-BORNE DISEASES OF LIVESTOCK IN THE TROPICS JUNE 2009
ICTTD PROJECTEXTENSION APPROVED
F R O M T H E E D I TO R
Gerrit Uilenberg
Looking over old documents I was reminded once again that an isolated sci-entific experi-ment often can-not lead directly to a definite answer. Nothing new of course, but it does no harm to keep in mind once more the value and shortcomings of statistics in science.Conclusions from experimental results are very often based on statis-tics, and can then only indicate a degree of probability, never an abso-lute truth. For example if a certain drug appears to be effective in an experiment, the efficacy of the treat-ment is considered statistically sig-nificant if there is a 95% of probabil-ity that it is not due to chance. This means that there is a 5% probability
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ICTTD-3
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In vitro feeding and photo-graph by Anne Marie Rhebergen (Utrecht Centre for Tick-borne Diseases (UCTD)
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that it is after all due to chance. As an example: If 20 different labo-ratories carry out an experiment on a drug which is in fact ineffective, on the average one of the teams may well find that the drug is statistically significantly effective, while (on the average) 19, the great majority, will
find no statistically significant effi-cacy. The team that found a statisti-cally significant efficacy enthusiasti-cally writes a manuscript that is readily accepted by a peer-reviewed journal, because the statistics are valid. The results of the laboratories that (correctly) found no statistically significant efficacy may not be pub-lished because journals are under-
standably less interested in negative results and the teams may also be less motivated in writing such a manuscript. The result is that the drug wrongly acquires the reputa-tion of being effective, or if one or two of the other teams succeed in getting their negative results pub-lished, its efficacy remains contro-versial.
OBITUARY
All having been involved in research on African ticks know the reputation and the name of Jane Walker. She passed away recently, and Ivan Horak, who was present when she died, has sent an obituary and a list of her publi-cations. No one is eternal, but it is nev-ertheless with great sadness that (a shortened version of) the obituary is inserted here.
Jane Brotherton Walker
Jane Brotherton Walker was born in Nairobi, Kenya on 31 January 1925 and grew up as a child on a farm in Kenya. After her primary school years she went to England, and because the Second World War was in progress, she did not see her parents for a pro-tracted period. It was during this time that Jane contracted poliomyelitis and spent several months in a plaster cast in hospital. Over the years the after-effects of the disease progressively affected her ability to walk, particular-ly during her later years. Jane studied at Liverpool University, where she obtained, as an external student, her MSc degree in 1959, and was awarded a DSc degree on her published work by the University of the Witwatersrand, Johannesburg in 1983.
Jane was first employed in 1949 as a Research Officer in the East African Veterinary Research Organization, Muguga, Kenya. She progressed to Senior Scientific Officer and then to Principal Scientific Officer, before vol-untarily leaving in 1966 to take up a post as Senior Professional Officer at the Veterinary Research Institute, Onderstepoort, upon the retirement of Dr Gertrud Theiler. At the Institute,
where she spent the rest of her work-ing life, she progressed through the ranks of Chief Professional Officer, Chief Veterinary Researcher and Specialist Scientist until her retirement in 1990. After retirement she continued to work at Onderstepoort in an honor-ary capacity for 3 days a week until 1998. During her working life, includ-ing her active years after retirement, Jane was sole, senior or co-author of 53 scientific publications and five books as well as the descriptions of 18 new tick species. She, herself, illustrat-ed many of the ticks with meticulously executed line drawings. For the illus-trations in her magnum opus, the Rhipicephalus species of the world, Jane used the services of André Olwage, a young commercial artist imbued with a gentleness and patience that he sorely needed with Jane’s insistence on the exactness of every detail. Her legacy in her chosen field of the taxonomy of ticks resides in her published works as well as in the train-ing she gave, and the wisdom she imparted to Ivan Horak, Arthur Spickett, Heloise Heyne, Trevor Petney and Dmitry Apanaskevich.
Jane’s prowess as a scientist was rec-ognized by her peers who conferred on
her three of the most prestigious awards in the field of biological sci-ences in South Africa, namely the 1988 Elsdon-Dew Medal of the Parasitological Society of Southern Africa, for services rendered to Parasitology in Africa, the Agricultural Science and Technology Woman of the Year Award for 1998, and the Theiler Memorial Trust Award in 1998 for exceptional service rendered to Veterinary Science in Africa. Her sci-entific writing skills were soon recog-nized at Onderstepoort and she was a member of the Editorial Committee of the Onderstepoort Journal of Veterinary Research from 1969 until 2000, a function she performed extremely punctiliously to the dismay, but nevertheless to the ultimate bene-fit, of many a sloppy author.
Jane had her own likes and dislikes amongst the tick genera. She was with-out doubt the expert on the genus Rhipicephalus, with which she had an ongoing love affair. She was greatly distressed when it was proposed that the genus Boophilus become a subge-nus of her beloved Rhipicephalus, a subject which the protagonists of this change preferred not to discuss with her. Jane also had a deep affection for the African Amblyomma ticks, but despite being involved in the descrip-tion of six Ixodes species and one argasid tick, she never liked ticks of the genus Ixodes or of the family Argasidae.
While working in Kenya Jane owned a horse, which she rode side-saddle, and also travelled in her Hillman Mynx automobile to localities that are now nearly inaccessible in a 4x4 vehicle. She also travelled to South Africa in the Hillman Mynx when she moved here from Kenya. In South Africa she
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owned a Mitshubishi Colt, especially fitted with hand-controls to compensate for the weakness in her legs, and it served as her daily mode of transport from her home to Onderstepoort.
Jane loved classical music, autobiogra-phies, natural science books and the BBC news, and she also took a lively interest in African politics. Her knowl-edge of the geography of the world and the exact locations of cities and towns was astounding. She never owned a TV set or a computer. She was a prodigious letter writer, and both her letters and manuscripts were written in pencil, of which she always had seven at hand. Jane kept carbon copies of her manu-scripts and most of her correspondence. She also kept nearly every letter, maga-zine, journal and book that she received, was given, or purchased, and, if her home had had the space, she might even have been tempted to keep every newspaper!
Upon returning home from work dur-ing August 1998, Jane fell from the back stairs of her home and thereafter ceased to drive her own car, relying on friends for transport. Walking became increasingly difficult, and unwillingly Jane had to acquire both a walking ring and a wheel chair. Jane disliked being house-bound intensely, and her friends, who took over her regular Friday shop-ping, used to load her in their cars, and after they had parked in the shade at the shopping centres with her inside, they did the house-shopping with Florah Kokoele, her faithful house assistant. In later years the strain on Jane’s body to get into a car was too great and her friends then took only Florah and her shopping list, which was most carefully composed in Jane’s hand-writing, to purchase the weekly necessities. Friday was shopping day, and no other day would do, so woe betide the authorities who decreed that certain public holidays must fall on Fridays!
With Jane’s death the scientific world has lost one of its most meticulous and experienced workers, and the field of tick taxonomy, particularly in Africa, will be infinitely poorer. Her friends have lost a true Lady and a loyal friend.
Jane died peacefully at home in Pretoria on Friday morning 3 April 2009 while having tea with Ivan Horak.
Publications
Books
1. Yeoman, G.H. & Walker, Jane B., assisted by Ross, J.P.J. & Docker, T.M. 1967. The ixodid ticks of Tanzania. A study of the zoogeogra-phyof the Ixodidae of an East African country. Commonwealth Institute of Entomology: London.
2. Walker, Jane B. 1974. The ixodid ticks of Kenya. A review of present knowledge of their hosts and distri-bution. Commonwealth Institute of Entomology: London.
3. Walker, Jane B., Mehlitz, D. & Jones, G.E. 1978. Notes on the ticks of Botswana. German Agency for Technical Coopperation, Ltd (GTZ): Eschborn.
4. Howell, C.J., Walker, J.B. & Nevill, E.M. 1978. Ticks, mites and insects infesting domestic animals in South Africa. Part 1. Descriptions and biology. Department of Agricultural Technical Services, Republic of South Africa, Science Bulletin no. 393.
5. Walker, Jane B., Keirans, J.E. & Horak, I.G. 2000. The genus Rhipicephalus (Acari, Ixodidae): a guide to the brown ticks of the World. Cambridge Academic Press: Cambridge.
PaPers
1. Walker, Jane B. 1955. Rhipicephalus pulchellus Gerstäcker, 1873: a description of the larva and nymph with notes on the adults and on its biology. Parasitology, 45: 95-98.
2. Walker, Jane B. 1956. Rhipicephalus pravus Dönitz, 1910. Parasitology, 46: 243-246.
3. Theiler, Gertrud, Walker, Jane B. & Wiley, A.J. 1956. Ticks in the South African Zoological Survey Collection. Part VIII. Two East African ticks. Onderstepoort Journal of Veterinary Research. 27: 83-99.
4. Walker, Jane B. 1957. Rhipicephalus humeralis Rondelli, 1926. Parasitology, 47: 145-152.
5. Walker, Jane B. 1959. Notes on the common tick species of East Africa. I. Introduction. Rhipicephalus appendiculatus and R. pravus. East African Veld, 5: 111-116.
6. Walker, Jane B. 1959. Notes on the common tick species of East Africa.
II. More species belonging to the genus Rhipicephalus. East African Veld, 5: 131-135.
7. Walker, Jane B. 1959. Notes on the common tick species of East Africa. III. The bont and bont-legged ticks. East African Veld, 5: 157-162.
8. Walker, Jane B. & Wiley, A.J. 1959. Rhipicephalus camelopardalis n. sp. (Ixodoidea, Ixodidae), a new spe-cies of tick from East African giraffes. Parasitology, 49: 448-453.
9. Walker, Jane B. 1960. Notes on the common tick species of East Africa. IV. The blue tick, the yellow dog tick and the fowl tick. East African Veld, 6: 9-13.
10. Walker, Jane B. 1960. Notes on the common tick species of East Africa. Cooper, McDougall & Robertson (E.A.) Ltd: Nairobi.
11. Walker, Jane B. 1962. Notes on the common tick species of East Africa. 2nd edition, revised. Cooper, McDougall & Robertson (E.A.) Ltd: Nairobi.
12. Dinnik, J.A., Walker, Jane B., Barnett, S.F. & Brocklesby, D.W. 1963. Some parasites obtained from game animals in western Uganda. Bulletin of Epizootic Diseases of Africa. 11: 37-44.
13. Walker, Jane B. & Parsons, B.T. 1964. The laboratory rearing of Amblyomma sparsum Neumann, 1899. Parasitology, 54: 173-175.
14. Walker, Jane B. 1966. Rhipicephalus carnivoralis sp. nov. (Ixodoidea, Ixodidae). A new spe-cies of tick from East Africa. Parasitology, 56: 1-12.
15. Walker, Jane B. 1966. Rhipicephalus reichenowi Zumpt, 1943: a re-description of the male and female and descriptions of the nymph and larva, together with an account on its known hosts and dis-tribution. Parasitology, 56: 457-469.
16. Clifford, C.M. & Walker, Jane B. 1966. Host and distribution records for several species of the genus Ixodes (Acarina: Ixodidae) that occur in East Africa. Revue de Zoologie et de Botanique Africaines, 74: 155-168.
17. Sweatman, G.K., Walker, Jane B. & Bindernagel J.A. 1969. Stages in the development of Choriopsoroptes kenyensis gen. et sp. n. (Acari: Sarcoptiformes: Psoroptidae), a body mange mite from captive African buffalo, Syncerus caffer, in Kenya. Journal
of Parasitology, 55: 1298-1310.18. Walker, Jane B. 1970. Notes on the
common tick species of East Africa. 3rd edition, revised. Cooper, McDougall & Robertson (E.A.) Ltd: Nairobi.
19. Hoogstraal, H., Walker, Jane B. & Neitz, W.O. 1971. Notes on African Haemaphysalis ticks. VII. H. (Rhipistoma) hyracophila sp. n. (Ixodoidea: Ixodidae), a parasite of hyraxes in South Africa. Journal of Parasitology, 57: 417-425.
20. Walker, Jane B. 1973. Acari of the Ethiopian Region. D. Suborder Ixodoidea Leach, 1815. Department of Agricultural Technical Services, Republic of South Africa, Entomology Memoir No. 29: 42-45.
21. Walker, Jane B., Bezuidenhout, J.D. 1973. Treatment of tick-infest-ed tortoises. Journal of the South African Veterinary Association, 44: 381.
22. Walker, Jane B. & Laurence, B.R. 1973. Margaropus wileyi sp. nov. (Ixodoidea, Ixodidae), a new spe-cies of tick from the reticulated giraffe. Onderstepoort Journal of Veterinary Research, 40: 13-21.
23. Hoogstraal, H., Kaiser, M.N., Walker, Jane B., Ledger, J.A., Converse, J.D. & Rice, R.C.A. 1975. Observations on the sub-genus Argas (Ixodoidea: Argasidae: Argas). 10. A. (A.) africolumbae, n. sp., a Pretoria virus-infected para-site of birds in southern and eastern Africa. Journal of Medical Entomology, 12: 194-201.
24. Clifford, C.M., Walker, Jane B. & Keirans, J.E. 1976. Ixodes (Afrixodes) bakeri Arthur & Clifford, 1961 (Acarina: Ixodidae): descriptions of the male and imma-ture stages from rodents and insec-tivores and notes on its biology in South Africa. Onderstepoort Journal of Veterinary Research, 43: 105-112.
25. Clifford, C.M., Walker, Jane B. & Keirans, J.E. 1977. Ixodes (Afrixodes) neitzi, n. sp. (Acarina: Ixodidae) from the mountain reed-buck in South Africa. Onderstepoort Journal of Veterinary Research, 44: 143-150.
26. Bulman, G.M. & Walker, Jane B. 1979. A previously unrecorded feeding site on cattle for the imma-ture stages of the spinose ear tick, Otobius megnini (Duges, 1844). Journal of the South African
Veterinary Association, 50: 107-108.
27. Walker, Jane B., Norval, R.A.I. & Corwin, M.D. 1981. Rhipicephalus zambeziensis sp. nov., a new tick from eastern and southern Africa, together with a redescription of Rhipicephalus appendiculatus Neumann, 1901 (Acarina, Ixodidae). Onderstepoort Journal of Veterinary Research, 48: 87-104.
28. Rechav, Y. & Walker, Jane B. 1981. Ixodid ticks on children. South African Medical Journal, 59: 889.
29. Keirans, J.E., Clifford, C.M. & Walker, Jane B. 1982. The Ixodes (Afrixodes) oldi group (Acari: Ixodidae) from subSaharan Africa with descriptions of five new spe-cies. Journal of Medical Entomology, 19: 309-329.
30. Norval, R.A.I., Walker, Jane B. & Colborne, J. 1982. The ecology of Rhipicephalus zambeziensis and Rhipicephalus appendiculatus (Acarina: Ixodidae) with particular reference to Zimbabwe. Onderstepoort Journal of Veterinary Research, 49: 181-190.
31. Clifford, C.M., Walker, Jane B. & Keirans, J.E. 1983. Clarification of the status of Rhipicephalus kochi Dönitz, 1905 (Ixodoidea, Ixodidae). Onderstepoort Journal of Veterinary Research, 50: 77-89.
32. Horak, I.G., Potgieter, F.T., Walker, Jane B., De Vos, V. & Boomker, J. 1983. The ixodid tick burdens of various large ruminant species in South African nature reserves. Onderstepoort Journal of Veterinary Research, 50: 221-228.
33. Walker, Jane B. & Schultz, K.C.A. 1984. Records of the bont tick, Amblyomma hebraeum, from the angulate tortoise, Chersina angula-ta, and the leopard tortoise, Geochelone pardalis. Onderstepoort Journal of Veterinary Research, 51: 171-173.
34. Pegram, R.G., Clifford, C.M., Walker, Jane B. & Keirans, J.E. 1987. Clarification of the Rhipicephalus sanguineus group (Acari, Ixodoidea, Ixodidae). I. R. sulcatus Neumann, 1908 and R. turanicus Pomerantsev, 1936. Systematic Parasitology, 10: 3-26.
35. Pegram, R.G., Keirans, J.E., Clifford, C.M. & Walker, Jane B. 1987. Systematic clarification of the Rhipicephalus sanguineus group (Acari, Ixodoidea, Ixodidae).
II. R. sanguineus (Latreille, 1806) and related species. Systematic Parasitology, 10: 27-44.
36. Walker, Jane B. & Olwage, A. 1987. The tick vectors of Cowdria ruminantium (Ixodoidea, Ixodidae, genus Amblyomma) and their dis-tribution. Onderstepoort Journal of Veterinary Research, 54: 353-379.
37. Pegram, R.G., Walker, Jane B., Clifford, C.M. & Keirans, J.E. 1987. Comparison of populations of the Rhipicephalus simus group: R. simus, R. praetextatus, and R. muhsamae (Acari: Ixodidae). Journal of Medical Entomology, 24: 666-682.
38. Walker, Jane B., Keirans, J.E., Pegram, R.G. & Clifford, C.M. 1988. Clarification of the status of Rhipicephalus tricuspis Dönitz, 1906 and Rhipicephalus lunulatus Neumann, 1907 (Ixodoidea, Ixodidae). Systematic Parasitology, 12: 159-186.
39. Pegram, R.G. & Walker, Jane B. 1988. Clarification of the biosys-tematics and vector status of some African Rhipicephalus species (Acarina: Ixodidae). In: Service, M.W. (ed.) Biosystematics of hae-matophagous insects. Systematics Association Special Volume No. 37: 61-76. Clarendon Press: Oxford.
40. Walker, Jane B. 1990. Two new species of ticks from southern Africa whose adults parasitize the feet of ungulates: Rhipicephalus lounsburyi n. sp. and Rhipicephalus neumanni n. sp. (Ixodoidea, Ixodidae). Onderstepoort Journal of Veterinary Research, 57: 57-75.
41. Lessard, P., L’Eplattenier, R., Norval, R.A.I., Kundert, K., Dolan, T.T., Croze, H., Walker, Jane B., Irvin, A.D. & Perry, B.D. 1990. Geographical information systems for studying the epidemiology of cattle diseases caused by Theileria parva. Veterinary Record, 126: 255-262.
42. Walker, Jane B. 1991. A review of the ixodid ticks (Acari, Ixodidae) occurring in southern Africa. Onderstepoort Journal of Veterinary Research, 58: 81-105.
43. Walker, Jane B., Keirans, J.E. & Pegram, R.G. 1993. Rhipicephalus aquatilis sp. nov. (Acari: Ixodidae), a new tick species parasitic mainly on the sitatunga, Tragelaphus spekei, in East and Central Africa.
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Onderstepoort Journal of Veterinary Research, 60: 205-210.
44. Keirans, J.E., Walker, Jane B., Horak, I.G. & Heyne, H. 1993. Rhipicephalus exophthalmos sp. nov., a new tick species from southern Africa, and redescription of Rhipicephalus oculatus Neumann, 1901, with which it has hitherto been confused (Acari: Ixodida: Ixodidae). Onderstepoort Journal of Veterinary Research, 60: 229-246.
45. Walker, Jane B., Pegram, R.G. & Keirans, J.E. 1995. Rhipicephalus interventus sp. nov. (Acari: Ixodidae), a new tick species close-ly related to Rhipicephalus tricus-pis Dönitz, 1906 and Rhipicephalus lunulatus Neuman, 1907, from East and Central Africa. Onderstepoort Journal of Veterinary Research, 62: 89-95.
46. Horak, I.G., Braack, L.E.O., Fourie, L.J. & Walker, Jane B. 2000. Parasites of domestic and wild animals in South Africa. XXXVIII. Ixodid ticks collected from 23 wild carnivore species. Onderstepoort Journal of Veterinary Research, 67: 239-250.
47. Horak, I.G., Fourie, L.J., Heyne, H., Walker, Jane B. & Needham, G.R. 2002. Ixodid ticks feeding on humans in South Africa: with notes on preferred hosts, geographic dis-tribution, seasonal occurrence and transmission of pathogens. Experimental and Applied Acarology, 27: 113-136.
ConferenCe Presentations
Walker, Jane B. “Some observations on the classification and biology of ticks belonging to the genus Rhipicephalus, with special refer-ence to the immature stages”. Scientific Conference on the Epidemiology of Arthropod-borne Diseases, Nairobi, Kenya, 11 January 1961. Published in 1961: East African Medical Journal, 38: 232-238
Walker, Jane B.. “Ticks and human disease in tropical Africa”. International Symposium on Medicine in a Tropical Environment, Pretoria, South Africa, 19-23 July 1976. Published in 1977: Proceedings of the International Symposium, South Africa 1976, pp. 276-290. A.A. Balkema, Rotterdam,
The Netherlands. Walker, Jane B. “Survey techniques
for tick species affecting domestic animals”. International Workshop on the Ecology and Control of External Parasites of Cattle of Economic Importance in Latin America, Cali, Colombia, 25-30 August 1975. Published in 1978: Thompson, K.C. (ed). Proceedings of a Workshop on the Ecology and Control of Ectoparasites on Bovines in Latin America, 1975, pp. 9-22. CIAT, Cali, Colombia.
Walker, Jane B., Spickett, A.M., Brett, Susan & Horak, I.G. Poster “The immature stages of the com-mon ticks of domestic animals in South Africa”. International Conference on Tick Biology and Control, Tick Research Unit, Rhodes University, Grahamstown, South Africa, 27-29 January 1981.
Walker, Jane B. & Olwage, A. “The tick vectors of Cowdria ruminantium (Ixodoidea, Ixodidae, genus Amblyomma) and their distribution”. International Workshop on Heartwater: past, present and future, Berg-en-Dal, Kruger National Park, South Africa, 8-11 September 1986. Published in 1987: Onderstepoort Journal of Veterinary Research, 54: 353-379.
Penzhorn, B.L., Krecek, R.C., Horak, I.G., Verster, A.J.M., Walker, J.B., Boomker, J.D.F., Knapp, S.E. & Quandt, S.K.F. “Parasites of African rhinos: a documentation”. Symposium on Rhinos as Game Ranch Animals, Onderstepoort, South Africa, 9-10 September 1994. Published in 1994: Proceedings of a Symposium on Rhinos as Game Ranch Animals, Onderstepoort, 9-10 September 1994, pp.168-175.
Horak, I.G. & Walker, Jane B. 1999. “The relationships of some South African ticks in the genus Rhipicephalus”. Third International Conference on Ticks and Tick-borne Pathogens: into the 21st Century. High Tatera Mountains, Slovakia, 30 August-3 September 1999. Published in 2000: Proceedings of the Third International Conference on Ticks and Tick-borne Pathogens: into the 21st Century. Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia, edited by M. Kazimírová, M. Labuda & P.A. Nuttall, pp. 261-263.
Horak, I.G. & Walker Jane B. 2003. “The taxonomy, distribution and
biology of Rhipicephalus muhsamae, R. praetextatus, R. simus and R. ger-trudae”. Third National Workshop on Ticks and Tick-borne Disease in the Sudan. Khartoum, Sudan, 18-20 August 2003. Published in 2003: Sudan Journal of Veterinary Science and Animal Husbandry, 42: 100-104.
theses
Walker, Jane B. 1959. A comparative study of the larvae and nymphae of ticks belonging to the genus Rhipicephalus in East Africa. MSc Dissertation, Liverpool University UK.
Walker, Jane B. 1983. Studies on African ticks (Acarina, Ixodoidea). DSc Thesis, University of the Witwatersrand, South Africa.
new tiCk sPeCies desCriBed By Jane walker or with others
Argas africolumbae Hoogstraal, Kaiser, Walker, Ledger, Converse & Rice, 1975
Haemaphysalis hyracophila Hoogstraal, Walker & Neitz, 1971
Ixodes neitzi Clifford, Walker & Keirans, 1977
Ixodes brewsterae Keirans, Clifford & Walker, 1982
Ixodes catherinei Keirans, Clifford & Walker, 1982
Ixodes corwini Keirans, Clifford & Walker, 1982
Ixodes macfarlanei Keirans, Clifford & Walker, 1982
Ixodes zairensis Keirans, Clifford & Walker, 1982
Margaropus wileyi Walker & Laurence, 1973
Rhipicephalus carnivoralis Walker, 1966
Rhipicephalus zambeziensis Walker, Norval & Corwin, 1981
Rhipicephalus lounsburyi Walker, 1990
Rhipicephalus neumanni Walker, 1990
Rhipicephalus aquatalis Walker, Keirans & Pegram, 1993
Rhipicephalus exophthalmos Keirans & Walker, 1993
Rhipicephalus interventus Walker, Pegram & Keirans, 1995.
Rhipicephalus oreotragi Walker & Horak, 2000
Rhipicephalus warburtoni Walker & Horak, 2000
Ivan G. Horak
GENERAL
Ticks: biology, disease and control: Book review Bowman, A. & Nuttall, P. (editors) 2008. Ticks: biology, disease and con-trol. Cambridge University Press, ISNB: 978-0-521-86761-0.Alan Bowman and Pat Nuttall have done an excellent job of bringing together and editing another textbook on ticks in the style of Physiology of Ticks edited by Fred Obenchain and Rachel Galun; and Morphology, Physiology and Behavioural Biology of Ticks edited by John Sauer and Alexander Hair. This volume is by 51 well established researchers who have written 21 substantial and inspiring review articles, together with extensive listings of recent literature. The cover-age is good, missing only gut and digestion, and behaviour. Also tick-associated pathogens comprise just one review on viruses, two on one bacteri-um each, and two on one genus of pro-tozoa each. The coverage has clearly attempted to give generic examples as comprehensive as possible, and cer-tainly all the transmitted pathogens would require a separate textbook.
Thus the book is a good reflection of current research interests so it must be made clear that it is intended for researchers rather than non-specialists seeking facts about the basics of tick biology. For that Daniel Sonenshine’s two volumes on Biology of Ticks remains the only modern source. I can confidently recommend buying this, or persuading your librarian to order it. (AW)(GU: The book is based on most of the (updated) papers in the supplement of Parasitology, 2004 [see NL n° 28, pp. 5-6].)
Proceedings of the 9th STVM bien-nial conference (Merida, Mexico)
These proceedings have now been published as a special issue of the Annals of the New York Academy of Sciences:Sparagano O.A.E., Maillard J.-Ch. & Figueroa J.V. (eds). Animal biodiversi-ty and emerging diseases: prediction and prevention. Ann. N.Y. Acad. Sci., 1149, 404 pp. (ISBN n° 978-1-57331-714-6)Most relevant papers are presented in this issue of the ICTTD newsletter, some will be in the next.
Proceedings of TTP-6 (Buenos Aires, Argentina)
Another important meeting was the 6th International Conference on Ticks and Tick-borne Pathogens, held in September, 2008 in Argentina, with the theme “The challenge of ticks in a warming planet”. The Book of Proceedings (in fact the Book of Abstracts), is freely available as a pdf file, on request to [email protected] and contains the abstracts of all
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presentations. There are too many (hundreds) to mention here, but select-ed papers will later be published in full in a special issue of Veterinary Parasitology, edited by Theo Schetters.
An introductory lecture by Michael Samish gave the history of TTP meet-ings (Ticks and tick-borne pathogens: 1976-2008). The conference was dedi-cated to two eminent scientists in our field, who passed away in 2007, David Kemp and Milan Labuda (pp. IX-XII).
Ticks involved in cattle and deer deaths in the USA?
Unexplained deaths of cattle, horses and deer in South Dakota may be due to multiple factors, including severe winter weather, lack of nutrition, pos-sibly infectious diseases, but also ticks, heavy infestations by the “winter tick” (Dermacentor albipictus) being a com-mon factor in the deaths. It is known that heavy infestations by this one-host tick may cause the death of moose (Alces alces) calves. From ProMED-mail
Recent publications
Magona J.W., Walubengo J., Olaho-Mukani W., Jonsson N.N. & Eisler M.C. 2009. Diagnostic value of rectal temperature of African cattle of varia-ble coat colour infected with trypano-somes and tick-borne infections. Vet. Parasitol., 160: 301-305. (E-mail: [email protected])(The authors found that the most suita-ble time of the day to detect pyrexia could be between 1 and 5 p.m., when they found that the differences in rectal temperature between healthy and unhealthy cattle (local zebus) were most pronounced, even though there was the likelihood of getting false pos-itives (healthy cattle with high rectal temperatures). The authors also found an influence of coat colour: cattle with a grey colour had a significantly higher mean rectal temperature than cattle with a black spotted white coat, while the difference with light brown, pure black and pure brown coats was not significant.)(GU: The subject is of obvious practi-cal importance, as anyone with some experience in hot climates will know.
However, the numbers in each group are so small that no conclusions are justified. The total number was 20, 10 healthy and 10 unhealthy ones. And there was only one animal with a grey coat colour and one with a black coat with white spots; even if one takes the temperature of one animal that hap-pens to be grey 20 times that does not make it a sample of 20 grey animals! The results of the influence of the time of the day are even more surprising. While it is important to take into account the influence of ambient tem-perature on rectal temperature for assessing pyrexia, truly pyrexic ani-mals are detected in hot climates when the ambient temperature is cool, cer-tainly before noon. Diurnal changes in ambient temperature are known to influence the rectal temperature of cat-tle even in temperate regions in sum-mer, resulting in false positives!)
Seitzer U. & Ahmed J. 2008. Attenuated vaccines for animal diseas-es. Vaccine, 26 (Suppl. 6): G1-G3. (E-mail: [email protected])(This paper is the introduction to a conference on attenuated vaccines, and a useful summary. Many (but not all) of the contributions were published as a supplement to vol. 26 of Vaccine. The conference was held in April 2007, organised by the Asian compo-nent of ICTTD-3, and mainly (but not only) concerned Asia. Relevant papers are dealt with elsewhere in this issue.) (GU)
And three references concerning the impact of climate change:
Estrada-Peña A. 2009. Tick-borne pathogens, transmission rates and cli-mate change. Front. Biosci., 14: 2647-2780. (E-mail: [email protected])(A review. The author”s abstract: “Ticks are parasites that expend most of their life cycles off the host. Most important parts of the tick life cycle are directly dependent upon climate. There exist some concerns about the effects of the forecasted climate change on the geographical distribution of ticks. As tick life cycle dynamics would also be affected, the transmission of tick-borne pathogens could also be transformed by climate trends. Tick cycles are the result of complex inter-actions between climate, hosts popula-tions, landscape characteristics, and the fine modulation of the populations of every partner involved, and not a
simple, straightforward correlation between abundance and climate. The understanding of the climate niche used by different tick species may help in the search of clues towards a clarifi-cation of the expected effects of cli-mate changes on the reported tick range shift. Populations of ticks occu-pying different portions of a wide geo-graphical range may use different “portions” of the climate envelope, therefore resulting in misinterpreta-tions from modeling results. Some advances can be foreseen in the com-plex task of modeling tick-host-patho-gen interactions.”)
George J.E. 2008. The effects of global change on the threat of exotic arthro-pods and arthropod-borne pathogens to livestock in the United States. Ann. N.Y. Acad. Sci., 1149: 249-254. (E-mail: [email protected])(Arthropods and arthropod-borne path-ogens, many of which are so-called “emerging infectious diseases” and many are zoonoses, may be introduced by wind, birds, domestic animals, wildlife and humans, as well as animal products, even intentionally (bioterror-rists). Global change includes not only climatic change on a global level, but also modifications in ecosystems by changes in land use (which again may sometimes be the consequence of cli-mate change). This newsletter only deals with ticks and TBDs. Examples of tick-borne zoonotic exotic (for the USA) diseases are CCHF and louping-ill. Although the distribution of CCHF co-incides with the distribution of Hyalomma ticks (which do not occur in the western hemisphere) the virus has been isolated from other tick gen-era; CCHF is not a direct threat to live-stock but to humans. Louping-ill is a zoonosis but also affects livestock directly; American Ixodes spp. that are related to the natural vector , I. ricinus, may be potential vectors. Heartwater (Ehrlichia ruminantium infection) is another risk to livestock, that could be introduced from the Caribbean or with wildlife from Africa (and at least one competent potential vector exists in the USA, Amblyomma maculatum). And then there are the Boophilus ticks and bovine piroplasmosis that have been eradicated from the USA, but not from Mexico, and are only kept from spreading into the USA by constant surveillance; acaricide resistance and wild ungulates are complications.)(GU: See also the temporary introduc-
tion of equine piroplasmosis in Florida, now apparently terminated (see below).)
Olwoch J.M., Reyers B., Engelbrecht F.A. & Erasmus B.F.N. 2008. Climate change and the tick-borne disease, theileriosis (East Coast fever) in sub-Saharan Africa. J. Arid Environm., 72: 108-120.(E-mail: [email protected])(Compiled from the abstract: Olwoch et al. predicted the impacts of climate change on the range of the tick-borne disease theileriosis (East Coast fever (ECF)) in sub-Saharan Africa using a species distribution model and current and future climates simulated by the nested regional climate model DARLAM (Division of Atmospheric Limited Area Model). The results, based on the predicted distribution of the main tick vector species (Rhipicephalus appendiculatus) and its host, cattle, showed that the Northern Cape and Eastern Cape provinces of South Africa, Botswana, Malawi, Zambia and eastern DRC show increases in ECF suitability. Other areas in sub-Saharan Africa show dif-ferent rates of range alteration. These range alterations are in response to the predicted general change in mean min-imum, maximum temperature and rain-fall in the months of January and July. The ECF sub-Saharan risk map pro-vided is presented as a necessary tool to complement existing traditional con-trol methods. The authors conclude that understanding and mapping changes in space and time of ECF are a prerequisite to sustainable disease reduction since it is then possible for current and future disease control pro-grams to be timely and directed at spe-cific areas based on risk maps.) (US)
TICKS
Alan Walker’s contribution
Some comments on the state of tickol-ogy may be appropriate here. The sad news of Jane Walker’s passing away has prompted a feeling of the end of an era amongst some of us. Similarly, at a meeting this year of the British Society for Parasitology, I found myself trying to convince two biochemists that amongst the 400 delegates there were probably more who would call them-
selves Biochemist, with qualifications to match, than would call themselves Parasitologist. The academic subject of parasitology in some countries has been taken over by many technical dis-ciplines, but there are very many stud-ies of parasites, or tiny bits of them, being published. Tickology is going the same way, whilst the numbers of papers grows steadily. The Web of Science database, searched for tick as keyword in the title gave, for each dec-ade starting from 1959-68, hits of: 483, 761, 1397, 1566, and 2185 papers – this shows the historical trend as fairly straight line of steady increase. To indicate total annual production of papers on ticks a search for tick in title or in the abstract, for 2008 only, revealed 849 papers. The era when ticksters, as Jane called them, formed a single peer group ended several dec-ades ago, but as the book of Bowman and Nuttall shows, there is no stopping the march of work on ticks. Since none of us now attempts to keep up with them all, just a small selection is reviewed here.
Annals of the New York Academy of Sciences has concentrated on Animal Biodiversity and Emerging Diseases: Prediction and Prevention, for its vol-ume 1149 of 2008. This consists of many short contributions to the 9th Biennial Conference of the International Society for Tropical Veterinary Medicine, held in 2007 at Merida, Mexico. The following seven papers on ticks all from the above vol-ume are briefly covered below.
George D.R., Guy J.H., Arkle S., Harrington D. De Luna C., Okello E.J., Shiel R.S., Port G. & Sparaganoa O.E.A. Use of plant-derived products to control arthropods of veterinary importance: a review. pp 23-26. (E-mail: [email protected])(The authors review 22 papers describ-ing plant-derived products for the con-trol of mainly mites on domestic ani-mals. There are certainly many prom-ising candidates for commercialization but the problems of getting these prod-ucts legally registered for use, then manufactured for easy purchase, remain uncertain in many cases.)
Blouin E.F., Manzano-Roman R., de la Fuente J. & Kocan K.M. Defining the role of subolesin in tick cell culture by use of RNA interference. pp. 41-44. (E-mail:
[email protected])(Subolesin is a regulatory protein that controls multiple cellular pathways in many invertebrates and vertebrates, indicating how conserved evolutionari-ly it is. Recently the gene for subolesin has been found using infestations of mice by ticks, and a recombinant ver-sion of the protein shows promise as vaccine antigen. This paper describes preliminary methods using RNA inter-ference in cell cultures of Ixodes scapularis to find more about the func-tion of this protein in ticks.)
Mosqueda J., Cossio-Bayugar R., Rodriguez E., Falcon A., Ramos A., Figueroa J.V. & Alvarez A. Primary midgut, salivary gland, and ovary cultures from Boophilus microplus. pp. 49-52.(E-mail: [email protected])(This describes establishment of pri-mary cell cultures from the above organs using a fairly standard medium for this purpose of an equal mixture of Leibovits-15 medium and minimum essential medium with Hank’s salts, supplemented with foetal calf serum at 20% and bovine albumin powder at 0.1%, all protected by antibiotics.)
Kaewhom P., Stich R.W., Needham G.R. & Jittapalapong S. Molecular analysis of calreticulin expressed in salivary glands of Rhipicephalus (Boophilus) microplus indigenous to Thailand. pp. 53-57.(E-mail: [email protected])(Calreticulin is a protein of many func-tions; it binds calcium, which renders it inactive, and binds to misfolded pro-teins, preventing them from being exported from the endoplasmic reticu-lum. It is common in salivary glands of ticks, it has been isolated from ticks of five genera, and may have anti-thrombocytic and complement-inhibit-ing activity. Thus it may be a suitable vaccine antigen. The authors cloned, sequenced and analysed the cDNA from Boophilus microplus.)
Granjeno-Colin G., Hernandez-Ortiz R., Mosqueda J., Estrada-Mondaca S., Figueroa J.V. & Garcia-Vazquez Z. Characterization of a vitellogenin gene fragment in Boophilus microplus ticks. pp. 58-61. (E-mail:[email protected])(The authors describe the isolation, cloning, and characterization of a frag-ment of thevitellogenin gene from a Boophilus
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microplus. This glyco-lipo-protein is a precursor of egg yolk. The authors found a high level of conservation of this protein. Because of its location and function in the cattle tick, the authors consider this protein an obvi-ous candidate to be evaluated for vac-cination of cattle.)
Reis R.C.S. Fernandes E.K.K. & Bittencourt V.R.E.P. Fungal formula-tions to control Rhipicephalus san-guineus engorged females. pp. 239-241. (E-mail: [email protected])(The authors studied the effect in vitro of treating this dog tick with formula-tions of conidia of the usual fungi for this type of work: Beauveria bassiana or Metarhizium anisopliae. Formulations consisted of polymerized cellulose gel or an emulsifiable con-centrate of polymerized cellulose gel combined with calcium phenylsul-fonate and nonyl phenol ethoxylated. They found the formulation of B. bas-siana with both these carriers caused the highest control percentage (87%) of the ticks.)
Bahiense T.C., Fernandes E.K.K., Angelo I.C., Perinotto W.M.S. & Bittencourt, V.R.E.P. Performance of Metarhizium anisopliae and its combination with deltamethrin against a pyrethroid-resistant strain of Boophilus microplus in a stall test. pp. 242-245. (E-mail: [email protected])(The authors treated cattle infested with Boophilus microplus with conidia of this fungus in an aqueous suspen-sion, a deltamethrin solution, or both fungus and deltamethrin combined. They found the mean mortality 32.57% in the groups treated with fun-gus alone, 38.58% in those groups treated with deltamethrin, and 30.92% in those treated with fungus and chem-ical combined.)
Experimental and Applied Acarology, 2008, has all issues, 1 to 4, of volume 46 dedicated to: diseases of mites and ticks: from basic pathology to microbi-al control. The following four papers were about ticks.
Hynes W.L., Stokes M.M., Hensley S.M., Todd S.M. & Sonenshine, D.E Using RNA interference to determine the role of varisin in the innate immune system of the hard tick Dermacentor variabilis (Acari: Ixodidae). pp. 7-15.(E-mail: [email protected])
(Varisin is a small peptide in the func-tional class of defensins of inverte-brates. These have a major role in the innate immune system of invertebrates, and varisin is known to occur in ticks where they are produced by the haemocytes. The authors used RNA interference to stop expression of vari-sin in this American dog tick. Comparisons of ticks with stopped expression of varisin, against ticks injected with double stranded varisin RNA, showed that the antimicrobial activity of the haemolymph plasma was reduced 2–4 fold. The authors concluded that varisin is the major defensin in tick haemolymph of this tick. However, as the next paper, by some of the same co-authors shows, it may not be as simple as that.)
Kocan K.M., de la Fuente J., Manzano-Roman R., Victoria Naranjo V., Hynes W.L. & Sonenshine D.E. Silencing expression of the defensin, varisin, in male Dermacentor variabi-lis by RNA interference results in reduced Anaplasma marginale infec-tions. pp.17–28.(E-mail: [email protected])(These authors studied the role of vari-sin in the immunity of ticks to the bac-terium Anaplasma marginale which is also a natural pathogen of cattle. They used similar methods to the above paper, to test the hypothesis that stop-ping expression of varisin would increase infections in ticks with the bacteria. However, the results demon-strated that bacterial numbers were reduced significantly in the varisin deficient silenced ticks. The authors discuss various ways in which this unexpected result could have occurred, but clearly more studies with this valu-able technique are required. It could be that results of studies on innate immu-nity of ticks to pathogens will differ greatly depending on whether the path-ogen is naturally transmitted by the tick, and thus well adapted to it, or is an experimentally introduced pathogen not adapted to the tick.) (This paper was also presented as an Epub ahead of print in NL n° 37)
Ginsberg H.S. Potential effects of mixed infections in ticks on transmission dynamics of pathogens: comparative analysis of published records. pp. 29–41. (E-mail: [email protected])( Dr Ginsberg has analysed published data on four species of ticks showing
multiple infection with naturally trans-mitted pathogens for evidence of inter-actions between the pathogens them-selves. There is increasing evidence of the pathogenic effect that various tick transmitted pathogens have on the ticks, so that for example, if one patho-gen is damaging the salivary glands then another pathogen may find it dif-ficult to get into its vertebrate host via the same glands. Conversely there may be mutualistically beneficial effects between different pathogens in the same tick. Some valuable and simple mathematical methods are shown for use in such studies. As the author has demonstrated in earlier studies, when the number of tick bites is relatively low, changes in prevalence in ticks are predicted to have a commensurate effects on pathogen transmission. But when the number of tick bites is high, changes in pathogen prevalence in ticks will have relatively little effect on levels of transmission to hosts.)(This paper is also reviewed under TICKBORNE DISEASES)
Fernandes E.K.K. & Bittencourt V.R.E.P. Entomopathogenic fungi against South American tick species. pp. 71–93. (E-mail: [email protected])(This is a review of results of several studies which were conducted in South America on the potential for use in tick control of entomopathogenic fungi such as Beauveria or Metarhizium.)
Estrada-Pena A. Climate, niche ticks and models. 2008 Paasitol.Res., 103 (suppl. 1): 87-95.(E-mail: [email protected])(This paper reviews attempts to answer the basic question: how it is possible to predict the spatial distribution of a tick species using only variables of cli-mate? Particular focus is devoted to the problem of getting models to work with only partial data of known distri-bution locations and climatic data of varying levels of relevance to the small microclimates in which ticks spend most of their lives. The examples used focus on Ixodes ricinus in Europe, also the potential suitability of north Africa and southern Europe for spread of Boophilus annulatus, Dermacentor marginatus, Hyalomma excavatum, Hyalomma marginatum, Rhipicephalus bursa, and Rhipicephalus turanicus. Various maps derived from models are shown for potential tick distribution in Europe but it is difficult to relate the
conclusions drawn from these maps with personal knowledge of distribu-tion of at least I. ricinus. As the author emphasizes in the final section of the paper, under typical conditions in Europe there is a huge difference between the general climatic suitability for a species of tick over a country wide area of land, and where the tick can actually survive in abundance. The latter is defined by how humans have changed the microclimates suitable for ticks by urban, industrial, transport and agricultural development. A plea is made for better models that will incor-porate such factors. I would add a plea for more and systematic field collec-tion of ticks to test these models. A similar phenomenon can be seen stark-ly for tsetse by examining on Google Earth those scans at high definition that show parts of northern Nigeria that used to be widely infested. Human population pressure and agricultural development has converted the natural savannah, still visible in small Reserve areas, into fields and pastures with hostile microclimate for tsetse.)
Reck Jr. J., Berger M., Terra R.M.S., Marks F.S., da Silva Vaz Jr. I., Guimaraes J.A. & Termignoni C. 2009. Systemic alterations of bovine hemostasis due to Rhipicephalus (Boophilus) microplus infestation. Res.Vet.Sci., 86: 56–62.(Email: [email protected])(The importance of this tick as a direct parasite of cattle is well known from studies in Australia and the Americas, causing reduction in gain of weight and hide damage. The loss of produc-tion is considered to be more due to anorexia than actual blood loss. However, the mechanism of this ano-rexia and general malaise associated with heavy tick infestation has been poorly studied. The authors set out to improve understanding of the physiol-ogy of cattle during experimental infestations with this tick. Collagen and ADP-induced platelet aggregation, also coagulation, decreased in infested cattle whilst platelet counts and fibrin-ogen increased. The authors discuss their results in terms of two hypothe-ses: that the alterations observed were due to (i) action of parasite salivary molecules injected into the cattle inhibiting platelet aggregation and coagulation or (ii) compensatory responses to the ticks.)
Zabalgogeazcoa I., Oleaga A., &
Perez-Sanchez R. 2008. Pathogenicity of endophytic entomopathogenic fungi to Ornithodoros erraticus and Ornithodoros moubata (Acari: Argasidae). Vet. Parasitol., 158: 336–343. (E-mail: [email protected])(This is the first report of attempted control of these ticks using ento-mopathogenic fungi. The authors examined pathogenicity of strains of Beauveria bassiana, Lecanicillium lecanii and Tolypocladium cylin-drosporum. Two strains of Beauveria and one of Tolypocladium caused in Spanish O. erraticus mean mortality rates between 34.4% and 62% and one strain of Beauveria caused in African O.moubata mean mortality rates of 31.9%. The remaining strains caused lower mortality rates and were not considered effective. )
Coskun S., Girisgin O., Kürkcüoglu M., Malyer H., Girisgin A.O., Kirimer N. & Kemal Hüsnü Baser K.H. 2008. Acaricidal efficacy of Origanum onites L. essential oil against Rhipicephalus turanicus (Ixodidae). Parasitol. Res., 103: 259–261.(E-mail: [email protected])(Origanum species are very common in Mediterranean countries and O. onites is the dominant species in the northwest of Turkey. Essential oils of Origanum species have antibacterial, antifungal, , antioxidative and antipara-sitic activities. The major constituent of these oils is carvacrol, and is con-sidered responsible for these therapeu-tic properties. Five Origanum species are cultivated and more than 4,500 tons are exported annually. Steam extracts of O.onites were made, and contained 64.3% of the active carvac-rol. These were diluted at 7 concentra-tions ranging from 1.5% to 100% by weight in ethanol and were tested against R. turanicus in vitro. At con-centrations of 25% and above all tested ticks were killed after 24 hours expo-sure to treated filter papers.)
Srivastava R., Ghosh S., Mandal D.B., Azhahianambi P., Singhal P.S., Pandey N. N. & Swarup D. 2008. Efficacy of Azadirachta indica extracts against Boophilus microplus. Parasitol. Res., 104: 149–153.(E-mail: [email protected])(The authors used preparations of the well known botanical insectide aza-dirachtin or neem, to control this tick, and compared it with extracts of Prunus persica, Mangifera indica, and
Psidium guajava plants. Extracts were made with ethanol and dried. For use they were all dissolved in water to 8% by weight. The neem was 80% effica-cious, the other extracts less so.)
So far Alan’s review
Peter Willadsen’s contribution
Gao J., Luo J., Fan R., Schulte-Spechtel U.C., Fingerle V., Guan G., Zhao H., Li Y., Ren Q., Ma M., Liu Z., Liu A., Dang Z., Sugimoto C. & Yin H. 2009. Characterization of a con-cealed antigen Hq05 from the hard tick Haemaphysalis qinghaiensis and its effect as a vaccine against tick infesta-tion in sheep Vaccine, 27: 483-490.(E-mail: [email protected])(The Hq05 antigen was identified through differential screening of a cDNA library using an anti-tick sali-vary gland serum and anti-tick saliva serum. The former was generated by injecting rabbits with salivary gland extract, while the latter was obtained by repeated tick infestation. The anti-gen was considered to be “concealed” then on the basis that it is not detected by the latter serum. The antigen is 20 kDa and with a novel sequence that suggests it should be secreted and sol-uble. It is present in nymphas and adults, and in salivary glands but not midguts. Vaccination of sheep with a recombinant antigen did not affect tick survival but did reduce female engorgement weight (13%), egg weight per tick (40%) and egg hatcha-bility (37%). There was no apparent effect on nymphs. The authors suggest the antigen could be useful in a cock-tail vaccine.)
Hajdusek O., Sojka D., Kopacek P., Buresova V., Franta Z., Sauman I., Winzerling J. & Grubhoffer L. 2009. Knockdown of proteins involved in iron metabolism limits tick reproduction and development. Proc. Natl. Acad. Sci. USA, 106: 1033-1038. (E-mail: [email protected])(For most organisms, iron is both essential and potentially toxic. Relatively little is known about iron metabolism in ticks, but this paper marks a big advance and deserves to be read by all interested in tick bio-chemistry and physiology. In addition to a previously described intracellular ferritin (FER1) the authors describe a new secreted ferritin (FER2) and an
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iron regulatory protein IRP1. Using principally RNAi to knock down gene expression, they provide evidence FER1 stores iron after the bloodmeal and that without it reproduction is reduced; FER2 is required for repletion and that without it there is significant tick mortality during feeding while IRP1 was necessary for egg develop-ment. In its absence hatching was reduced. These observations are drawn together into a tentative model of iron metabolism in ticks. The relevance for tick and disease con-trol comes from the suggestion that these proteins, particularly FER2, could be targets for a vaccine. Hopefully someone will do the experi-ments.)
Konnai S., Nakajima C., Imamura S., Yamada S., Nishikado H., Kodama M., Onuma M. & Ohashi K. 2008. Suppression of cell proliferation and cytokine expression by HL-p36, a tick salivary gland-derived protein of Haemaphysalis longicornis. Immunology, 126: 209-219. (E-mail: [email protected])(The p36 gene product from Dermacentor andersoni has been pre-viously shown to have immunosup-pressive activity, and homologues have been identified in Rhipicephalus appendiculatus and Amblyomma vari-egatum. This paper describes the relat-ed gene and protein from Haemaphysalis longicornis, HL-p36. The protein sequences show quite low levels of identity, the highest being 21% with the protein from A. variega-tum. In H. longicornis, the gene appears to be expressed only in sali-vary glands, and it was expressed in nymphs and adults only after blood feeding, reaching a peak after three days. The result was confirmed by Western blots, that also showed detec-tion of the protein by antibodies to lar-val, nymphal and adult tick saliva, showing the protein was apparently secreted during tick infestation. In vitro, the recombinant protein sup-pressed proliferation of mouse periph-eral blood mononuclear cells in a dose dependent manner, and altered cytokine expression. The suppression was relieved by a monoclonal anti-body to HL-p36. In vivo, suppression was also seen following injection of recombinant HL-p36 several times over 10 days. Splenocytes from these mice were also used for microarray analysis of the effects of exposure to
the immunosuppressant. Enormous numbers of changes were seen, with alterations in the expression of over 5000 genes. Little detail is provided for these experiments, though a small number of the genes showing greatest change were associated with immune function. The authors suggest that the protein is probably important for pathogen trans-mission, and that it could be useful in an anti-transmission or anti-tick vac-cine, particularly in view of the relief of immunosuppression by antibody. As always, the paper also raises some interesting questions. Although the authors talk about effects at the tick attachment site, the microarray results would suggest a systemic effect on the mouse. Further, while the delay in peak HL-p36 production to the third day of tick feeding may be of benefit to a pathogen being transmitted, is it a sensible strategy for an attached tick? It would be interesting to tie these observations into a better understand-ing of the tick-host biology.)
Saldivar L, Guerrero F.D., Miller R J., Bendele K.G., Gondro C. & Brayton K.A. (2008) Microarray analysis of acaricide-inducible gene expression in the southern cattle tick, Rhipicephalus (Boophilus) microplus Insect Mol. Biol., 17: 597-606.(E-mail: [email protected])(The use of microarray arrays to examine in an “hypothesis-free” way the changes in gene expression that may contribute to a physiological response is now well established for organisms with well characterized genomes, though its application to organisms without extensive genomic information remains a challenge, as this publication shows. The authors use an array containing 13000 R. microplus sequences to examine the effects of exposure to coumaphos, ivermectin, amitraz and permethrin on the up- and down-regulation of this gene set. Acaricide doses were chosen to induce low levels of mortality dur-ing the exposure period. The tick strain was resistant to coumaphos, amitraz and permethrin. Since micro-array experiments, in view of the very large data sets that result, are likely to yield significant numbers of false pos-itives, the authors also attempted to validate the results by further compar-ing them with the results of SAGE (Serial Analysis of Gene Expression) analysis, while as a further check
selected expression levels were also assessed by real time PCR.As a result, at least three genes, legu-main (a proteinase), glutathione-S-transferase and a putative salivary gland-associated protein were identi-fied as of interest. The difficulties of the work are at least as informative. While some of the microarray results were confirmed by SAGE and rtPCR, there were also discrepancies and inconsistencies. More importantly, the number of genes identified as differ-entially expressed in microarrays was relatively large, say 70 to 270 depending on the criteria used, but only 10 – 15% of these differentially expressed genes could be even tenta-tively identified by sequence compar-isons. This reflects the paucity of sequence information for tick genes and the importance of acquiring such information.)
Smith A., Guo X., Fuente J., Naranjo V., Kocan K. & Kaufman W.R. 2009. The impact of RNA interference of the subolesin and voraxin genes in male Amblyomma hebraeum (Acari: Ixodidae) on female engorgement and oviposition. Exp. Appl. Acarol., 47: 71-86.(E-mail: [email protected])(Two of the most promising antigens identified over recent years are sub-olesin, found in a range of tick species, and voraxin, identified in Amblyomma hebraeum. Both have the ability to dra-matically affect tick reproduction, including female fertility, though by different mechanisms. This detailed paper examines the effect of RNA interference on female engorgement and oviposition when dsRNA is inject-ed into A.. hebraeum male ticks. Briefly, the effect of suppressing sub-olesin was dramatic, with high male mortality and pronounced reductions in female engorgement rates, weights and egg production. Voraxin dsRNA gener-ally gave no significant effect and although the use of dsRNA to suppress both subolesin and voraxin simultane-ously may have given stronger effects than subolesin alone for some experi-mental parameters, the differences were not striking. However, semi-quantita-tive PCR showed also that expression of the voraxin genes was not sup-pressed; that is, the experiments were inconclusive for voraxin. The authors suggest the observations support the investigation of subolesin as a protec-tive antigen for A.. hebraeum.
Two papers present work on attempts to develop a vaccine against Hyalomma in India:
Azhahianambi P., de la Fuente J., Suryanarayana V.V.S. & Ghosh S. 2009. Cloning, expression and immu-noprotective efficacy of rHaa86, the homologue of the Bm86 tick vaccine antigen, from Hyalomma anatolicum anatolicum. Parasite Immunol., 31: 111–122.(E-mail: [email protected])(The homologue of the Bm86 antigen from Hyalomma anatolicum anatoli-cum has been cloned, expressed in Pichia and assessed in vaccination tri-als. The amino acid sequence shows 63 and 64% identity with that of Austra-lian Bm86 and Argentinean Bm95, while comparison of the sequence from two Indian isolates of the tick, Ludhiana and Izatnagar, showed less than 1% difference. The general struc-ture of seven EGF (epidermal growth factor)-like domains is also preserved. Following vaccination of cattle, infesta-tions were performed with larval and adult ticks. There was a 44% reduction in the numbers of larvae engorging. In addition, 36% of adult female ticks were rejected, compared with 10-12% on control cattle. Engorgement weights and egg mass were also reduced, though less dramatically, giving a cal-culated vaccine efficiency against adult ticks of 62%. The authors suggest the antigen could be used in an integrated control program for the tick.)
Ghosh S., Ray D.D., Vanlahmuaka, Das G., Singh N.K., Sharma J.K. & Azhahianambi, P. 2008. Progress in development of vaccine against Hyalomma anatolicum anatolicum—Indian scenario. Vaccine, 265: G40-G47. (E-mail: [email protected])(A number of partially protective native antigens from Hyalomma anatolicum have been investigated over the last decade. All have been iso-lated using, as a critical step, immu-noaffinity chromatography on antibody columns. This paper gives a brief sum-mary of the status of six of them and includes, for one, experiments on the effect of vaccination with the tick anti-gen on Theileria annulata. Although the work has been substantially pub-lished before, this makes a convenient place to gain an overview and it directs readers to relevant older papers.)
So far Peter’s review
Gervásio Bechuara’s contribution
Bravo M., Henriquez H. & Coronado A. 2008. In vitro efficacy of amitraz and cypermethrin on Boophilus micro-plus from dairy farms in Lara State, Venezuela. Ann. N.Y. Acad. Sci., 1149: 246-248.(E-mail: [email protected])(The objective was to determine the in vitro efficacy of amitraz and cyperme-thrin, the main acaricides used in Venezuela, through the adult immer-sion test. For that, a sample of 480 engorged females weighing 220 mg on the average was collected from four dairy farms (120 ticks/farm) and divid-ed into groups of 10 ticks each. Commercial preparations of amitraz (52, 104, 208, 416 and 832 ppm) and cypermethrin (37.5, 75, 150, 300, 600 ppm) were used throughout the experi-ment. Ticks were placed on a glass slide at 27ºC and 85% relative humidi-ty (RH) and incubated for 18 days. The egg masses were collected, weighed, separated in vials and allowed to hatch at 85% RH and 27ºC for 21 days. Both the emerged larvae and eggs were quantified in each tube in order to determine the efficacy percentage and the resistance factor. The efficacy aver-age of amitraz was 31%, 51%, 51%, 60% and 61% for the above concentra-tions, respectively, while that of cyper-methrin was 14%, 12%, 17%, 20% and 43% for the above concentrations, respectively. The amitraz resistance factor for each of the 4 farms was 3.14, 1.19, 1.88, and 1.89, whereas cypermethrin resistance was 8.89, 6.03, 7.12, and 18.45. . There were no statistically significant differences between the effectiveness of different concentrations of amitraz or cyperme-thrin. It was concluded that higher concentrations do not increase the effi-cacy of the products. (GU: I find this difficult to understand!))
Cuore U., Trelles A., Sanchis J., Gayo V. & Solari M.A. 2007. Primer diag-nóstico de resistencia al Fipronil en la garrapata común del ganado Boophilus microplus. (First report of resistance to Fipronil in the cattle tick Boophilus microplus). Veterinaria (Montevideo), 42 (165-166): 35–41. (In Spanish.) (E-mail: [email protected])(The authors report the first diagnosis of resistance to Fipronil in the cattle tick Boophilus microplus in Uruguay since the beginning of its use eight years ago in this country, in contrast
with the much longer development of resistance to organophosphates and synthetic pyrethroids. Ticks suspected to present resistance to Fipronil showed a significantly different behav-iour in both the stable trial and repro-duction compared to a susceptible strain. In fact, the Fipronil efficacy on the life cycle of resistant and suscepti-ble strains was 66% and 96%, respec-tively.)
Labruna M.B., Naranjo V., Mangold A.J., Thompson C., Estrada-Peña A., Guglielmone A.A., Jongejan F. & de la Fuente J. 2009. Allopatric speciation in ticks: genetic and reproductive diver-gence between geographic strains of Rhipicephalus (Boophilus) microplus. BMC Evol. Biol., 9: 46. (doi:10.1186/1471-2148-9-46). (E-mail: [email protected] and [email protected])(In my view this is one of the most rel-evant paper in the last years on the speciation of the cattle tick Rhipicephalus (B.) microplus, which will certainly have an influence in the area of tick taxonomy and immune tick control as well. The existence of struc-tural and genetic differences among R. microplus strains are well known, sug-gesting that biogeographical and eco-logical separation may have resulted in boophilid ticks from America/Africa and those from Australia being differ-ent species. To test this hypothesis the authors performed experiments to characterize the reproductive perfor-mance of crosses between R. microplus from the three continents and the genetic diversity of strains from Australia, Asia, Africa and America. The results showed that the crosses of Australian x Argentinean (or Mozambican) strains are infertile while crosses of Argentinean x Mozambican strains are fertile. These results showed that tick strains from Africa (Mozambique) and America (Argentina) are the same species, while ticks from Australia may actually rep-resent a separate species. The genetic analyses of mitochondrial 12S and 16S rDNA and microsatellite loci were not conclusive when taken separately, but there was evidence that Australian tick strains are genetically different from Asian, African and American strains. These results support the hypothesis that at least two different species share the name R. microplus. The authors proposed that these species could be redefined as R. microplus Canestrini,
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1887 (for American and African strains) and probably the old R. austra-lis Fuller, 1899 (for Australian strains), which needs to be redescribed.)(GU: Obviously a paper of great importance! Yes, crosses between Australian and with Argentinean and between Australian and Mozambican strains were infertile, those between Argentinean and Mozambican strains fertile. But only one Australian strain was used. Genetical studies appear to indicate 2 or more clusters, one group-ing Indonesian, Australian and New Caledonian strains, another one grouping other Asian, African and American strains. As the authors say, experiments with more tick strains from different geographical locations are needed before the Australian (and Indonesian and New Caledonian) ticks can be considered to be a different species from the others, and before resurrecting the species B. australis. If confirmed, there may be indeed impor-tant implications for immunological control of these ticks. The question is: Can ticks evolve into different species in the short time that they have been moved by man? But of course we don’t know how long those on the Indonesian islands have been isolated from those on the Asian mainland. There is in any case little doubt that the Boophilus ticks in Australia were introduced with Indonesian cattle and none at all that those in New Caledonia came with Australian mules (Rageau & Vervent, 1959). It is also likely, although not documented, that Boophilus microplus ticks in Latin America were introduced with zebu cattle from southern Asia, not Indonesia. However, although the authors state as a matter of fact that the introduction of B. microplus into Africa took place with animals from India, after the epidemic of rinderpest in the 19th century, this is not docu-mented either, although likely. But large numbers of cattle were also imported at that time into southern Africa from Madagascar, and it is sometimes assumed that these were at the origin of B. microplus in southern Africa. It is still not clear where the Malagasy Boophilus ticks originated. A large proportion of the human popu-lation of Madagascar is of Indonesian origin, although it is unlikely that they could take cattle or other hosts of Boophilus on such a journey. But if the ticks were introduced from Africa, it means that they were already present
on the East coast of Africa at an early time)
Lysyk T.J. 2008. Effects of ambient temperature and cattle skin tempera-ture on engorgement of Dermacentor andersoni. J. Med. Entomol., 45: 1000-1006. (Email: [email protected].)(In this paper the author designed experiments to determine whether changes in skin temperature of Angus (from 29ºC to 34ºC) and Holstein cat-tle (from 32ºC to 35ºC) held at ambi-ent temperatures ranging from 10ºC to 30ºC influenced engorgement of female Dermacentor andersoni. Results showed that changes in skin and ambient temperature strongly influenced the proportion of ticks that successfully engorged and both the engorgement period and weight, but less the proportion of dead ticks. Actually, these relationships differed between experiments using either Angus or Holstein cattle, however these differences were reduced when expressed in relation to skin tempera-ture, suggesting that the thermal envi-ronment of the breeds is an important characteristic determining engorge-ment success. Results indicated that ticks respond to changes in the thermal environment of the host, and these changes may be important to engorg-ing ticks exposed to fluctuating spring weather.)
Mendes M.C., Pinto Lima C.K. & Pereira, J.R. 2008. Práticas de manejo para o controle de o carrapato Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) em propriedades localizadas na região de Pindamonhangaba, Vale do Paraíba, São Paulo. (Farm management practic-es for the control of the tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) on farms in the region of Pindamonhangaba, Vale do Paraíba, São Paulo, Brazil.). Arq. Inst. Biol. S. Paulo, 75: 371-373. (In Portuguese.) (A survey about practices adopted for tick control was carried out on 40 farms located in Pindamonhangaba, Vale do Paraíba, state of São Paulo, Brazil. The questionnaires applied to the producers in the year of 2004 showed that amitraz is the main chemi-cal acaricide used in that region, fol-lowed by the association of organo-phosphate with pyrethroid, and macro-cyclical lactones. However, the majori-ty of farmers (95%) have used thera-
peutical acaricide treatment without information about the main acaricide groups.)
Nava S., Mangold A.J. & Guglielmone A.A. 2009. Field and laboratory studies in a Neotropical population of the spinose ear tick, Otobius megnini. Med. Vet. Entomol., 23: 1–5. (E-mail: [email protected])(In this study, one ear of each of five cows on a property in the province of Córdoba, Argentina, was inspected monthly from December 2004 to November 2006 to determine the pres-ence of Otobius megnini (Dugès) and to ascertain its seasonality. Ticks were collected to study the following biolog-ical parameters of immature and adult instars: pre-oviposition and oviposition periods, number of egg batches, incu-bation period, larval and nymphal moulting rate, engorgement weight of nymphs, pre-moult period and repro-ductive efficiency index (number of eggs laid/weight of female in mg).The abundance of immature stages was greater during January – April and August – October in the first and sec-ond years of the study, respectively. No larvae successfully moulted (GU: in vitro presumably) and parthenogene-sis was not observed. Several of the biological values observed for the tick population from the Neotropical zoo-geographic region showed marked dif-ferences to equivalent values for O. megnini populations from the U.S.A. (Nearctic) and India (Oriental). Nevertheless, the only two sequences of 16S rDNA deposited in GenBank from ticks originating in Argentina and allegedly in the U.S.A. indicate that they are conspecific (99.8% agree-ment). The authors consider the bio-logical differences among populations of this tick species to represent adapta-tions for survival at different condi-tions.)
Onofrio V.C., Barros-Battesti D.M., Labruna M.B. & Faccini J.L. 2009. Diagnoses of and illustrated key to the species of Ixodes Latreille, 1795 (Acari: Ixodidae) from Brazil. Syst. Parasitol., 72: 143–157.(E-mail: [email protected])(The authors presented an up-to date key to adults of the 8 currently valid Brazilian species of Ixodes based on scanning electron microscopy. They also discussed the relationships between Brazilian and other Neotropical Ixodes.)
Rosario-Cruz R., Almazan C., Miller R.J., Dominguez-Garcia D.I., Hernandz-Ortiz R. & de la Fuente J. 2009. Genetic basis and impact of tick acaricide resistance. Front. Biosci., 14: 2657-2665. (E-mail:[email protected])(A comprehensive review of acaricide resistance in Boophilus microplus. This subject has been studied for the last 20 years from the toxicology, metabolic and genomic points of view, however, only few methods for molecular detec-tion of resistance have been developed. Despite the relatively poor sensitivity for resistance detection, bioassays remain the method of choice for sus-ceptibility evaluation of tick popula-tions, based on their toxicological response after exposure to acaricides. Metabolic detoxification of acaricides is known to be mediated by multigene families of enzymes such as GST, esterases and mixed function oxidases (cytochrome P450). In addition, target site insensitivity has been studied on the sodium channel and acetylcholin-esterase genes. The use of genomics to understand acaricide resistance in B. microplus will play a major role in unraveling the molecular mechanisms of resistance. Advances in genomics will accelerate the development of new diagnostic and immunoprophylactic tools based on new vaccine candidates, and new molecular targets for acari-cide resistance detection and improve-ment of strategies for the control of ticks and tick-borne diseases in tropi-cal and subtropical areas of Mexico.)
So far Gervásio’s review
TICK-BORNEDISEASES
Recent publications
Ahantarig A., Trinachartvanit W. & Milne J.R. 2008. Tick-borne pathogens and diseases of animals and humans in Thailand. Southeast Asian J. Trop. Med. Public Health, 30: 1015-1032. (E-mail: [email protected]) (A. Ahantarig)(A useful review with an extensive list of references. It covers both human medicine and veterinary medicine, but the first sentence states: ‘”Ticks are
surpassed only by mosquitoes as arthropod vectors of disease (Dennis and Piesman, 2005)”. That may be true for human TBDs (and the refer-ence given only concerns tick-borne diseases of humans), but certainly not for the veterinary field, where ticks are vectors of more pathogens than any other group of arthropods. The paper reviews tick-borne pathogens of humans, domestic and wild animals diagnosed in Thailand by molecular techniques and also those diagnosed by other means. The high rate in stray cats of Hepatozoon infection, diagnosed microscopically, and the absence of Babesia bovis in cattle and ticks are surprising.) (GU)
Beck H.-P., Blake D., Dardé M.-L., Felger I., Pedraza-Díaz S., Regidor-Cerrilo J., Gómez-Bautista M., Ortega-Mora L.M., Putignani L., Shiels B., Tait A. & Weir W. 2009. Molecular approaches to diversity of populations of apicomplexan parasites. Internat. J. Parasitol., 39: 175-189.(E-mail: [email protected])(A review concerning major apicompl-exan pathogens. The authors’ abstract is: “Apicomplexan parasites include many parasites of importance either for livestock or as causative agents of human diseases. The importance of these parasites has been recognised by the European Commission and resulted in support of the COST (Cooperation in Science and Technology) Action 857 ‘Apicomplexan Biology in the Post-Genomic Era’. In this review we dis-cuss the current understanding in ‘Biodiversity and Population Genetics’ of the major apicomplexan parasites, namely the Eimeria spp., Cryptosporidium spp., Toxoplasma gondii, Neospora caninum, Theileria spp. and Plasmodium spp. During the past decade molecular tools for char-acterizing and monitoring parasite populations have been firmly estab-lished as an integral part of field stud-ies and intervention trials. Analyses have been conducted for most apicom-plexan pathogens to describe the extent of genetic diversity, infection dynamics or population structure. The underlying key question for all para-sites is to understand how genetic diversity influences epidemiology and pathogenicity and its implication in therapeutic and vaccination strategies as well as disease control. Similarities in the basic biology and disease or transmission patterns among this order
of parasites promote multifaceted dis-cussions and comparison of epidemio-logical approaches and methodologi-cal tools. This fosters mutual learning and has the potential for cross-fertili-sation of ideas and technical approaches.”) (GU)
Ginsberg H.S. 2008. Potential effects of mixed infections in ticks on trans-mission dynamics of pathogens: com-parative analysis of published records. Exp. Appl. Acarol., 46: 29-41. (E-mail: [email protected])(This paper critically reviews the effect of mixed infections in ticks. Most cases of higher or lower coinfections than would randomly be expected in field-collected ticks can be explained by tick-host-pathogen associations, but there are reports of negative or positive relationships between pathogens. E.g. Dermacentor andersoni ticks coinfect-ed with the non-pathogenic Rickettsia peacockii and R. rickettsii (the Rocky Mountain spotted fever agent) only transmit vertically the non-pathogenic species. Other reports show higher than random levels of coinfection, but it isn’t always clear whether this is due to interactions within the tick. Only laboratory experiments can exclude the influence of ecological factors. One should also distinguish infections in nymphs, which have only fed once in their life (the author presumably con-siders only unfed ticks), in the larval stage, from those in adults, which have fed twice; mixed infections in nymphs should therefore originate from feeding on a host infected with the various pathogens.) (GU)
Goddard J. & Varela-Stokes A.S. 2009. Role of the lone star tick, Amblyomma americanum (L.), in human and animal diseases. Vet. Parasitol., 160: 1-12.(E-mail: [email protected])(A critical review of the vector role of this important and aggressive tick, which occurs in much of the USA. Heavy infestations may occur on ani-mals in some areas, causing for instance high mortality in white-tailed deer fawns. It also readily attacks humans. It is definitely a biological vector of several pathogenic species of Rickettsia and Ehrlichia, infecting humans and animals, also of tularae-mia and of theileriosis of white-tailed deer. However, it does not seem to play a significant role in the ecology of Rocky Mountain spotted fever. It also appears capable of transmitting virus-
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es. The role in the epidemiology of borreliosis, Q fever, and babesiosis of white-tailed deer is unclear, while it does not appear to play a role in the epidemiology of anaplasmosis.)(GU: It is in fact important to report negative transmission experiments too, such as those reported for Anaplasma marginale and the agent of human granulocytic ehrlichiosis. In the past there have been negative experiments with A. americanum on the transmis-sion of Ehrlichia ruminantium (heart-water) and Theileria mutans, which both occur in the Caribbean; E. rumi-nantium is closely related to the Panoma Mountain Ehrlichia sp. , which is transmitted by this tick! The authors call the causal agent of theileriosis Theileria cervi, a species first described in fallow deer in Europe, and it has been shown experi-mentally that fallow deer cannot be infected with the theilerial agent of white-tailed deer. The authors appar-ently consider the name Babesia odo-coilei to be a synonym of B. cervi, a name which is new to me.)
Prokocimer M. & Potasman I. 2008. The added value of peripheral blood cell morphology in the diagnosis and management of infectious diseases part 1: basic concepts. Postgard. Med. J., 84: 579-585. (E-mail:[email protected])(A paper in a journal for human medi-cine, not directly about tick-borne dis-eases, is nevertheless refreshing read-ing. What is relevant to this newsletter is that examination of a peripheral blood smear is quick and cheap, allow-ing not only the identification of hae-moparasites, but can also provide clini-cally valuable information because of altered blood cell morphology and changes in blood cell counts.) (GU. I remember that during a meet-ing many years ago, a participant sug-gested that ELISA would be a good technique for diagnosing clinical bovine (erythrocytic) anaplasmosis. A simple blood-smear is so much cheap-er, quicker, simpler and accurate! Of course, an epidemiological survey is quite another matter.)
Salih D.A., Abdel Rahman M.B., Mohammed A.S., Ahmed R., Kamal S. & El Hussein A.M. 2009. Seroprevalence of tick-borne diseases among cattle in the Sudan. Parasitol. Res., 104: 845-850.(E-mail: [email protected]
[D.A. Salih])(600 sera from zebu cattle and zebu-Friesian crosses in northern, eastern, central and western Sudan were exam-ined by indirect ELISA for antibodies to Theileria annulata, Babesia bigemi-na, Anaplasma marginale and Theileria mutans. The area south of about 12° was not included. Antibodies to these pathogens were found in all sites, seroprevalence to each varying apparently with the climatic conditions for the vectors. This is the first time antibodies to A. marginale are reported in northern Sudan.) (GU)
Swai E.S., Karimuribo E.D., Kambarage D.M. & Moshy W.E. 2009. A longitudinal study on morbidity and mortality in youngstock smallholder dairy cattle with special reference to tick borne infections in Tanga region, Tanzania. Vet. Parasitol., 160: 34-42. (E-mail: [email protected])(Smallholder dairy farms were defined as having less than 10 cattle. The cattle were mostly crossbreds of Friesian x local breeds (Tanzanian shorthorn, Sahiwal or Boran). All calves less than 1 year old on the study farms were included and the farms were visited 11 times at intervals of 2 months. At the end data were obtained for almost 550 animalsSera were collected at each visit as well as information for each animal over the past 2 months. The sera were examined by ELISA at ILRI (Nairobi) for antibodies to Theileria parva, T. mutans, Anaplasma margin-ale, Babesia bigemina and B. bovis. Suspect clinical and PM cases of TBDs were confirmed by blood smears, and lymphnode smears were made in case of suspicion of theilerio-sis, and stained and examined at the regional laboratory in Tanga. Tick-borne diseases, particularly ECF and anaplasmosis were the main caus-es of morbidity, and caused over half of all deaths of the calves (which was 11.6%). ECF was responsible for 37% of overall mortality, anaplasmosis for 18%.)(GU. A praiseworthy attempt to obtain more accurate data on losses due to TBDs, not made easy because so many factors interfered (zero-grazing or not, different acaricidal treatments, differ-ent breeds with different susceptibili-ties to the various TBDs, etc.) . I wouldn’t call the Sahiwal a local breed, in fact not even the Boran.)
Zhu B.Y., Hartigan A., Reppas G.,
Higgins D.P., Canfield P.J. & Šlapeta J. 2009. Looks can deceive: Molecular identity of an intraerythrocytic apicom-plexan parasite in Auistralian gliders. Vet. Parasitol., 159: 105-111.(E-mail: [email protected])(Not directly relevant to tropical live-stock, but of considerable interest nev-ertheless! A protozoan parasite found in red cells of this marsupial would have been identified on the basis of its morphology with the light microscope as a typical species of Hepatozoon (haemogregarines). But looks can be deceptive! Using molecular techniques (PCR of SSU rDNA and LSU rDNA) it was more closely related to the cyst-forming Coccidia, in particular the Sarcocystidae, than to the haemogre-garines (Adeleidea). Molecular taxono-my is an important tool!) (GU)
PIROPLASMOSIS
Equine piroplasmosis in Florida
The quarantine in Florida, where Theileria equi infection had been reported (see the two previous issues of the NL, was lifted in February.
From ProMED mail
Drug treatment
Human piroplasmosis may be caused by various species of Babesia and other piroplasm species, some of which may be nearer to the genus Theileria, such as “Babesia” microti. My veterinary background made me always wonder why effective treatment of such cases did not make more use of molecules known already to be effective in cases of theileriosis and/or babesiosis in domestic animals. Of course, toxicity and even efficacy often differ between different animal spe-cies, and a drug which is effective and without danger for cattle may not be suitable for use in humans. Nevertheless….But of course the opposite is also valid, and a recent ProMED mail post-ing of the 23rd of February made me think of this. It drew the attention once again to the risk of B. microti in blood transfusion, because of an increase in transfusion-associated human cases in New York City. (Over 80 human cases
of transfusion-associated babesiosis have been reported in the USA since 1979.) Standard treatment for human babesiosis was a combination of clin-damycin and quinine for 7 days, but more recently the combination of atovaquone and azithromycin has been shown to be equally effective and to result in fewer side effects. And of course blood exchange transfusion as a supportive treatment is indicated in severe cases. Any drug which is effective against a blood parasite of the group causing malaria, babesiosis, theileriosis, or even against any of the Apicomplexa (think of the anti-coccidiosis drug halofuginone, which proved to be effective (but too toxic) against bovine theileriosis), should be looked at, but development costs and regulations, as well as the limited market, are not stimulating.
Recommended reading: Vial H.J. & Gorenflot A. 2006. Chemotherapy against babesiosis. Vet. Parasitol., 138: 147-160.
THEILERIOSIS
Bovine theileriosis in Australia
According to a recent (13th March) ProMED-mail taken verbatim from ABC Rural (Australian Broadcasting Corporation Rural) it appears that 35 cattle in northern New South Wales (NSW) were killed by a disease spread by “bush ticks” (GU: a name used in Australia for Haemaphysalis longi-cornis). The owner, with cattle brought into the area from elsewhere, is said to have lost 3 adult cattle to theileriosis, with others aborting or dead soon after birth. The owner complains about rele-vant agencies not having warned about the danger of bringing cattle into the region.There has also been an official com-munication in April by the Chief Veterinary Officer in New South Wales about the outbreak, saying that during 2008 theilerial parasites were detected in NSW associated with clinical dis-ease and over 860 deaths in 52 submis-sions, while there were only 9 submis-sions in 2007 and 8 in 2006 in which theileriosis was diagnosed. The majori-ty of the incidents have occurred in
introduced cattle of all age groups. On the other hand, Queensland authorities do not report an increase of clinical theileriosis. DNA comparison between Queensland and NSW isolates is being undertaken in Japan, to see whether there is any genetical disfference.
From ProMED-mail, ABC Rural and the Biosecurity Bulletin for Veterinarians
(GU: The only species known so far to occur in Australia is Theileria buffeli, which rarely causes clinical symptoms in Australia. (The communication by the NSW Chief Vet. Officer confusingly states that three Theileria species have been recognised in Australia, T. ser-genti, T. buffeli and T. orientalis; how-ever, the name T. sergenti is invalid for any bovine Theileria, and although there are DNA differences between various strains of the buffeli/orientalis group, it is yet unclear whether they should be considered as separate spe-cies and if so which one is T. buffeli and which one is T. orientalis.) But there has been an increased number of reports of clinical disease in NSW in the last year or two. As the ProMED-mail communication says, there is not enough information in the article. It is hoped that more detailed information will be available for the next issue of the NL. Many thanks to Dr. Bert de Vos for background information and to Prof. Karl Friedhoff for drawing our attention to the communication by the Chief Veterinary Officer.More about thess theilerias in Australia in newsletter n° 34 (pp. 15-17), by Peter Rolls and Bert de Vos.)
Corridor disease
Corridor disease is a well known form of virulent theileriosis in cattle, caused by Theileria parva when it is transmit-ted directly by vector ticks (Rhipicephalus appendiculatus group) from wild African buffalo to cattle. Such buffalo strains of T. parva, for-merly considered as a separate species, T. lawrencei, give initially rise to unde-tectable or low parasitaemias in cattle, and the infection is not usually trans-mitted between cattle (in contrast to classical East Coast fever, with high parasitaemias; ECF is readily transmis-sible by ticks between cattle).
However, on occasion Corridor disease has been transmitted between cattle, and successive cattle passages may result in higher parasitaemias, until it ressembles classical ECF. It is believed that ECF in cattle is transformed Corridor disease, with wild buffalo being the original host. Cattle in Southern province of Zambia have been badly affected by virulent theileriosis since many years now. As classical ECF was believed to have been eradicated there, it has been called Corridor disease at first, but fur-ther investigations have revealed that classical East Coast fever also occurs. And vaccination (infection and treat-ment) has contributed to the spread of ECF, by creating carriers of ECF, infective for ticks. A recent ProMED-mail message is resuscitating and rediscovering the problem. The Zambian Government is restocking the diminishing cattle popu-lation of Southern Province, but the authorities in Southern Province are afraid their efforts will be wasted unless Corridor disease is eradicated. They urge therefore to redesign the programme and put up dipping tanks to control ticks and vaccinate against the disease. One can only say that:1° Corridor disease is not, or at least not the only, problem, there is East Coast fever.2° Vaccination against Corridor disease is still problematic, and vaccination against ECF, while protecting individ-ual animals, also creates infective car-riers. 3° The only way to prevent Corridor disease is to rigorously separate buffa-lo and cattle (which at the same time would prevent the transmission of foot-and-mouth virus from carrier buf-faloes to cattle). Of course, using dip tanks (or other form of tick control) will help in the control of Corridor dis-ease as well as ECF. The possibility of eradicating the tick is an illusion (three-host tick with various host spe-cies, acaricide resistance, …..)
I wonder what our Belgian friends who are at the base of an ongoing immuni-sation programme against ECF in Zambia have to say. (GU)
Recent publications
Immunisation/Immunology
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The following papers are part of the special issue of Vaccine on attenuated vaccines for animal diseases arising from the meeting organised by Ulrike Seitzer and Jabbar Ahmed on behalf of the Asian component of ICTTD-3, which was held in April, 2007, at the Research Center Borstel, Germany (see in the section GENERAL).
Darghouth M.A. 2008. Review on the experience with live attenuated vac-cines against tropical theileriosis in Tunisia: Considerations for the present and implications for the future. Vaccine 26 (Suppl. 6): G4-G10.(E-mail: [email protected].). (In Tunisia, tropical theileriosis is mainly a problem for smallholder farmers with less than ten dairy cows, and this paper explores the best solu-tions for control in Tunisia. In terms of cost-benefit analysis, the eradication of the vector tick, by improving animal housing, would be the optimum solu-tion. The next best solution would be the provision of effective vaccination regimes, but currently live attenuated vaccines are the only option, with their attendant delivery constraints. Furthermore it is difficult to balance their protective abilities with lack of clinical signs and minimal loss of milk yield. Additionally such vaccines should not transmit to the tick vector. Given that even subclinical infections result in production losses, vaccines which would reduce these could well be economically advantageous. Small-scale studies on the safety of one such attenuated cell line suggested that it could be a suitable vaccine candidate.) (LG)
Hong Y., Luo J. & Lu W. 2008. Control of tropical theileriosis with attenuated schizont vaccine in China. Vaccine 26 (Suppl. 6): G11-G13.(E-mail: [email protected]). (This paper describes the history of vaccines against tropical theileriosis in Northern China. Prior to the 1960s, infection with T. annulata caused con-siderable economic losses particularly in cattle populations, but also in buffa-lo and yak. The first vaccines were derived from blood passages and irra-diated organ cultures from infected animals. Attenuated cell line vaccines were eventually commercialised, and together with gelatine preservation, have been widely used which has markedly reduced the incidence of the disease. However there are other
Theileria spp. in China which also cause disease, and development of safe effective vaccines is hampered by the inability to culture schizont infected lymph cells.) (LG)
Rasulov I., Fish L. & Shkap V. 2008. Vaccination of cattle against tropical theileriosis in Uzbekistan using auto-chthonous live vaccine. Vaccine 26 (Suppl. 6): G14-G16.(E-mail: [email protected])(Between 1976 and 1989, over 2.5 mil-lion animals were vaccinated in the former USSR, including Uzbekistan. However, following the breakup of the USSR, a new vaccine was developed which was derived from an Uzbekistan isolate, TAU-219, and since 1999 over 11,000 cattle have been vaccinated with this vaccine. Under experimental and semi-field conditions, the vaccine did not cause any drop in milk yield, nor adverse effects when given during pregnancy, although around 50% of cattle experienced fever of short dura-tion (3-4 days). No breed or age effects were observed. No increase in piroplasms was detected in blood fol-lowing vaccination.) (LG)
Seitzer U. & Ahmed J. 2008. Tropical theileriosis: Cytotoxic T lymphocyte response to vaccination. Vaccine 26 (Suppl. 6): G24-G28.(E-mail: [email protected]). (This paper reviewed the known protective mechanisms against tropical theileriosis and emphasised the role of cell mediated immunity. A number of different cell types and factors probably need to be induced for a vaccine to be effective, and include cytotoxic CD8+ T cells (CTL) and cytostatic cells, as well as macrophages, and cytokines such as interleukin (IL)-2 and interferon-γ (IFN γ). Recently a few T. annulata antigens that are recognised by CTL have been identified (see Newsletter 38: MacHugh et al. Parasite Immunol., 2008, 30: 385).) (LG)
Other papers:
Di Giulio G., Lynen G., Morzaria S., Oura C. & Bishop R. 2009. Live immunization against East Coast fever - current status. Trends Parasitol., 25: 85-92. (E-mail: [email protected]) (The authors give an overview of the use of the infection and treatment method (ITM) for the control of East Coast fever (ECF). They start by giv-
ing a brief introduction to ECF and its importance; then, they concentrate on the ITM, initially highlighting the prin-cipals of how it works and then the complications of large scale produc-tions of parasite stabilates required for the ITM. The authors then present data on several ITM trials but concentrating mainly on the use of the Muguga cock-tail in Tanzania, where a total of 361,000 animals had been immunized by the ITM by October 2008. Improved parasite stabilates and increased oxytetracycline concentra-tions during the ITM lead to a reduc-tion of immunized animals showing clinical ECF symptoms after the immunization to less than 0.05%. Less than 1% of vaccinated animals con-tracted ECF subsequently and total calf mortality was reduced by more than 92%. The review then switches to molecular tools that are available to study ITM efficacy and the effect of ITM on parasite populations. Availability of these molecular mark-ers provided evidence that recombina-tion is taking place in parasite popula-tions and that some genetic compo-nents of the vaccine stabilate have been detected in non-immunized ani-mals. The paper concludes by high-lighting areas in which the ITM could be improved and also identifies ques-tions for which we still do not have the answers.) (FK: The figure showing the satellite distribution in the T. parva genome was taken from a publication by Oura et al., 2003 and does not reflect the satellite marker number and distribu-tion accurately anymore. The actual chromosome sizes have been re-evalu-ated since then and were shown to be smaller and an error on chromosome 3 has resulted in the superimposing of satellite markers from two distinct parts of the chromosome, which are separated by the Tpr locus. The number of available markers has also increased since then.)
Marcotty T., Chaka G., Brandt J., Berkvens D., Thys E., Mulumba M., Mataa L. & van den Bossche P. 2008. The transfer of East Coast fever immu-nisation to veterinary paraprofessionals in Zambia. Rev. Sci. Tech. Off. Int. Epiz., 27: 741-749.(E-mail: [email protected]) (The paper describes the transition of East Coast fever immunizations in Eastern Zambia from the 1990s to the early 2000s. Up until 1996, the infec-
tion and treatment method (ITM) of immunization, using the local Katete strain, was implemented by veterinari-ans and all costs were paid for by the state. However, in 1996 the state veter-inarians started to charge for their service. The introduction of charges resulted in a large drop in vaccine uptake. In 1995 a total of 19,158 calves were immunized and this figure dropped to 2,121 in 1999. The Zambian state then changed the service provision again by having a part priva-tized but still subsidized ITM immuni-zation. This service was provided by paraprofessionals, trained people, who were based locally and had motorbikes for the distribution of the vaccine. A fee was still charged by the paraprofes-sionals, which covered the cost of sta-bilate purchase and a small profit for the workers. This change led to an increase of ITM uptake and in 2002 a total of 14,399 calves were immu-nized. The increase in the ITM uptake is not due to cost reduction as the para-professionals charge more than the nominal fee that was introduced by state veterinarians. The authors specu-late that an important factor for the increase in ITM uptake was due to the close working relationship between paraprofessionals and farmers.) (FK)
Namavari M., Hosseini M.H., Seghatoleslam A., Lotfi M., Shirazi A. & Sparagano O.A. 2008. Theileria lestoquardi antigens as potential vac-cine candidates. Ann. N.Y. Acad. Sci., 1149: 205-207.(E-mail: [email protected])(The authors have published a study investigating antibody production against antigens of T. lestoquardi schi-zont-infected cells by animals immuni-zed with a vaccine strain of T. les-toquardi from the Razi Vaccine and Serum Research Institute, Iran. The schizont-immunized animals showed considerable antibody production at day 21 which increased further by day 35. Five typical bands were observed at 73, 42, 20, 14, and 12 kDa. On the one hand, comparison of the results with earlier studies of Theileria spp. revealed two immunogenic schizont proteins with molecular weights of 73 and 42 kDa shared between T. annula-ta and T. lestoquardi. On the other hand, the proteins with molecular weights of 14 kDa and 12 kDa have not been seen to date in the other Theileria species. Since the presence of a common molecule to the three sta-
ges of T. annulata of around 73 kDa has also been reported, the authors suggest that further studies should eva-luate the 73-kDa protein as a potential vaccine candidate and that the 14- and 12-kDa proteins could be considered as diagnostic antigens.) (US)
Seitzer U., Liu Z., Yin H., Beyer D., Kullmann B., Miranda J. & Ahmed J.S. 2008. Immune response of Theileria sp.-infected sheep to recom-binant Theileria proteins. Ann. N.Y. Acad. Sci., 1149: 186-190.(E-mail: [email protected])(This study investigated the immune response of sheep infected by attrac-tion with 200 Haemaphysalis qinghai-ensis ticks (“tick infected”) from Theileria sp. (China) endemic areas or by inoculation with 8 ml blood (4% PPE) from a previously infected ani-mal (“blood infected”). Disease moni-toring showed that tick infected sheep had a significantly higher febrile reac-tion than blood infected sheep, and that parasitaemia was at low levels in both groups until day 27 p.i, then increased to reach an average of 3% PPE at day 32 p.i. Regarding the immune response, parameters of cellu-lar and humoral immunity against two recombinantly expressed Theileria proteins (rTaD and rTcSP) were inves-tigated. Although stimulation with Concanavalin A as a control showed significant suppression of approx. 5% of the stimulatory capacity in the infected animals, a significant prolifer-ative response both in the tick- and the blood-infected was observed against both recombinant proteins, the stimula-tion index being higher in the tick-infected animals. Regarding the humoral immune response, both groups of infected animals produced specific antibodies against both recom-binant proteins. The presence of spe-cific antibodies indicated that both proteins may be suitable for develop-ing and improving serology-based diagnostics for Theileria sp. (China) and further studies are aimed at eluci-dating the potential of these parasite antigens in protective immunity and thus vaccine development for this dis-ease.) (US)(GU: I’m still confused about patho-genic Theileria species in China. Sometimes authors write about Theileria sp. (China), sometimes spe-cific names are used, corresponding to Theileria sp. (China 1) and Theileria sp. (China 2). If these names and this
distinction are valid, what is meant by Theileria sp. (China)?)
Genomics/Cell biology
Bakheit M.A., Ahmed J.S. & Seitzer U. 2008. Existence of splicing variants in homologues of Theileria lestoquardi clone-5 gene’s transcripts in Theileria annulata and Theileria parva. Ann. N.Y. Acad. Sci., 1149: 212-213.(E-mail: [email protected])(Bakheit et al. performed a study to demonstrate the presence of clone-5 splice variants in T. annulata and T. parva schizont-infected cells. Previously, characterization of the clone-5 gene of T. lestoquardi, encod-ing an immunogenic protein which was used to establish an ELISA for malignant theileriosis, showed the presence of two splice variants due to a single intron in the gene. Prediction analysis and the absence of the intron in the non-proliferative Theileria luwenshuni implied a potential role of this protein in the biology of leukopro-liferative Theileria. This study showed that splice variants of the clone-5 homologoues in T. annulata and T. parva do occur on the transcript level and that splicing is due to the predicted intron sequence. It remains to be investigated whether splicing variants of clone-5 play a role in the ability for leukoproliferative Theileria to trans-form their host cell.) (US)
Beck H-P., Blakeb D., Dardéc M-L., Felgera I., Pedraza-Díazd S., Regidor-Cerrillod J., Gómez-Bautistad M., Ortega-Morad L.M., Putignanie L., Shiels, B. Tait, A. & Weir W. 2009. Molecular approaches to diversity of populations of apicomplexan parasites. Int. J. Parasit., 39: 175-189.(E-mail: [email protected]). (The European Union COST (Cooperation in Science and Technology) Action 857 ‘Apicomplexan biology in the post-genomic era’ brought together several distinct research themes on Apicomplexa of relevance to humans and livestock. This review discusses genetic diversity and its relevance to epidemiology and pathogenicity, in the major Apicomplexa: Eimeria spp., Cryptosporidium spp., Toxoplasma gondii, Neospora caninum, Theileria spp. and Plasmodium spp. Of rele-vance to this newsletter, T. annulata and T. parva exist as haploid genomes for most of their life cycle like other
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Apicomplexa; in their case in their mammalian hosts, and this facilitates the study of their genetic diversity. Many individual genes have been char-acterised in terms of their polymor-phisms, and between species compari-sons have enabled estimates of selec-tive pressure on some of the ortholo-gous genes of T. annulata and T. parva. More recently mini- and micro-satellite markers have been employed to investigate population genetics for these two Theileria spp. and indicated high population level diversity, possi-bly at least in part, through recombina-tion events. However these studies are more limited than those for other api-complexa and many unanswered ques-tions remain about the generation of the observed diversity.) (LG)
Guo X. & Silva J.C. 2008. Properties of non-coding DNA and identification of putative cis-regulatory elements in Theileria parva. BMC Genomics, 9: 582. (E-mail: [email protected]; [email protected]) (This paper is published in an online journal and accessible to everybody who has internet access. The authors used the genomes of T. annulata and T. parva, two closely related parasites, to investigate the function of non-coding DNA of these parasites and to identify possible transcription factor binding sites. Theileria parasites have very compact genomes with very short non-coding regions between genes (intra-genic regions IGRs) and very short introns. The authors found higher GC concentration and levels of sequence conservation in the IGRs 5’ rather than 3’ of genes, indicating that these regions contain possible elements for transcriptional control. The authors conducted a genome wide search for both parasites to identify functional elements, which are present 5’ to the transcription initiation sites of genes. They identified the 5 “best” elements for both T. parva and T. annulata, 3 of which are the same for both parasites. Two of these elements, 1 and 3, may be acting as transcription factor bind-ing sites because they are located, most frequently, in the first 60 bases 5’ to transcription initiation sites. Element 1 is found in most of the sub-telomeric variable secreted protein genes and has sequence homologies to the MZF1 binding site consensus, while element 3 has homologies to the binding site consensus for NF-kB.) (FK)
Lau A.O.T. 2009. An overview of the Babesia, Plasmodium and Theileria genomes: A comparative perspective. Mol. Biochem. Parasit., 164: 1-8.(E-mail: [email protected]). The sequencing of genomes continues apace, and we shall no doubt in the next few years see more and more, as even faster and cheaper sequencing methods are adopted, though the issues of storing, handling and analysing the resultant reams of data remain. Furthermore, it is still not clear how successful assembling large genomes de novo from short sequence reads will be. Several apicomplexan parasites have now been sequenced and this paper compares the three vector-borne Apicomplexa of the title. Genomes for eight Plasmodium spp., two Theileria spp. and three Babesia spp. have been published or are ongoing. At a gross level, Plasmodium spp. have 14 chro-mosomes (genome size ranging from 23.1 Mbp to 30 Mbp) in contrast to the 4 of Theileria spp. and Babesia spp. (genome size approx. 8.3Mbp), yet P. falciparum has only twice as many genes and P. y. yoelii has a similar number as the other two species. Theileria spp. and B. bovis have a higher percentage of intron-containing genes than Plasmodium spp. In con-trast to the subtelomeric and telomeric location of the antigenically diverse genes in Plasmodium spp., the genes involved in antigenic variation in Theileria spp. and Babesia spp. are in internal chromosomal regions as well as subtelomeric regions. Interestingly, B. bovis and T. parva have similar sub- and telomeric structure whereas T. annulata differs in having unique repeat regions in the subtelomeric region. Many of the genes for these species have been identified function-ally as kinases, phosphorylases, and DEAD-box RNA helicases, but many genes have no known function, includ-ing the largest protein family in Theileria spp.: Theileria-specific sub-telomeric protein (SVSP). Additionally the FAINT domain (frequently associ-ated in Theileria) is found in over 150 genes, but has no known function. As discussed elsewhere, there are many genes involved in specialised metabo-lism, and the genome sequences of apicoplasts (mitochondria) of apicom-plexa appear to be related to red and green algae.) (LG)
Lueder C. G. K., Stanway R. R., Chaussepied M., Langsley G. &
Heussler V.T. 2009. Intracellular sur-vival of apicomplexan parasites and host cell modification. Int. J. Parasit., 39: 163-173.(E-mail: [email protected]). (This invited review covers Plasmodium, Toxoplasma and Theileria spp. and their abilities to manipulate their respective mammalian host cells for their own survival. Unlike Plasmodium and Toxoplasma spp., the intracellular stage of Theileria spp. exists free in the cytoplasm and not inside a parasitophorous vacuole, and by as yet unclear mechanisms induces the host cell to divide. Although some secreted Theileria pro-teins of the AT-hook DNA-binding family have been shown to bind to host DNA, no parasite molecules have yet been identified that interact with host molecules to induce cell prolifera-tion and inhibit host cell apoptosis. Many signalling pathways are consti-tutively up-regulated and the parasite is decorated with host-derived IKK signalosomes, which result in constitu-tive NF-kB activation. However it is clear that many other host cell path-ways are also switched on, including those involving JNK and AP-1. Among other phenotypic changes, the authors show that T. annulata infected macro-phages lose their ability to spread on fibronectin, a feature that may be relat-ed to changes in the cell cytoskeleton. All three parasites activate PI3-Kinase (PI3-K) although the effects on the respective host cells are different, as in Theileria infected cells, PI3-K is asso-ciated with cell proliferation whereas in cells infected with the other para-sites, it is a cell survival signal. Although both Toxoplasma and Theileria activate STAT3 and up-regu-late anti-apoptotic molecules, this is associated with short-term survival and suppression of inflammatory signals in cells infected with the former parasite, whereas Theileria infected cells become transformed. Again there are many unanswered questions, and it is to be hoped that following the sequencing of apicomplexan genomes, it will become possible to ascribe bio-logical function to the many mysteri-ous genes of these parasites. Unfortunately Theileria biology is hampered by the inability to transfect and manipulate its genome.) (LG)
Schmuckli-Maurer J., Casanova C., Schmied S., Affentranger S., Parvanova I., Kang’a S., Nene V.,
Katzer F., McKeever D., Müller J., Bishop R., Pain A. & Dobbelaere D.A. 2009. Expression analysis of the Theileria parva subtelomere-encoded variable secreted protein gene family. PLoS ONE, 4: e4839. (E-mail: [email protected]) (This paper is published in an online journal and is accessible to everybody who has internet access. The paper looks at the subtelomeric encoded var-iable secreted protein (SVSP) gene family of Theileria parva. This gene family is found both in the T. annulata and T. parva genome and for the latter genome consists of 85 member genes making it its largest gene family. Microarray and qPCR analyses have shown that a wide range of these genes are transcribed during the sch-izont stage. The expression profile of these genes was found to depend largely on parasite genotype rather than host cell background. The majori-ty of these genes encode for proteins that contain signal peptide sequences, which imply that these proteins will be secreted into the host cell cyto-plasm. Expression studies of a single SVSP gene, TP03-0882, has shown that only a small percentage of para-sites express this protein and if this protein is expressed in mammalian cells then it translocates to the nucle-us, a process which is due to its 2 nuclear localization sequences. More studies are needed to elucidate the function of this gene family.) (FK)
Various
Bishop R., Musoke A., Skilton R., Morzaria S., Gerdner M. & Nene V. 2008. Theileria: life cycle stages asso-ciated with the ixodid tick vector. In: Bowman A.S. & Nuttall P. (eds.): Ticks: biology, disease and control. Cambridge University Press: 308-324. (E-mail: [email protected]) (This is a chapter in a book on ticks, which describes tick biology, diseases associated with ticks and tick control strategies and was published by Cambridge University Press in 2008. Chapter 14 of this book deals with Theileria with a strong bias to T. parva. The authors give a brief intro-duction to the more well known Theileria species, their life cycle and their tick hosts. It also covers genome comparisons between T. parva and T. annulata, transmission dynamics, vac-cine targets and expressed sequence tag (EST) methodologies to study
pathogen-tick interactions. The chapter finishes by highlighting areas of research that the authors think require further research; for example other Theileria life cycle stages within the tick other than the sporozoite, genome/transcriptome based pathogen-vector-host interactions as well as more detailed pathogen transmission studies and the effect of control strategies on these dynamics.) (FK)(GU: A general review of this book is presented in the section GENERAL.)
García-Sanmartín J., Barandika J.F., Juste R.A., García-Pérez A.L. & Hurtado A. 2008. Distribution and molecular detection of Theileria and Babesia in questing ticks from north-ern Spain. Med. Vet. Entomol., 22: 318-325.(E-mail: [email protected])(The paper contains so many data that it is difficult to improve on the authors’ abstract. They conducted a survey of piroplasm infection using the reverse line blot method in 562 questing adult ixodid ticks collected from ten differ-ent recreational mountain regions in the north of Spain. Using a panel of probes for 23 piroplasm species, 16 different piroplasms were indentified, with an overall prevalence of 9.3%. Most were Theileria spp.-positive (7.7%), 3.0% were positive for Babesia spp. and 1.4% of ticks har-boured both genera. Ixodes ricinus (Linnaeus, 1758), the most abundant tick in the vegetation, ranked third with regard to piroplasm infection prevalence (11.4%) after Rhipicephalus bursa (Canestrini & Fanzago, 1878) (16.0%) and Haemaphysalis punctata (Canestrini & Fanzago, 1878) (13.5%). Infection was detected in 6.2% of Dermacentor reticulatus (Fabricius, 1794) and in 1.1% of Haemaphysalis inermis (Birula, 1895), but was absent from Haemaphysalis concinna (Koch, 1844). Ixodes ricinus carried more piroplasm species (13), followed by H. punctata (10), D. reticulatus (8), R. bursa (3) and H. inermis (1). Although most of the positive ticks harboured a single infection (76.9%), mixed infec-tions with two or three different piroplasm species were also detected (23.1%).) (US)
Liu Z., Dang Z., Luo J., Yin H., Ahmed J.S. & Seitzer U. 2008. Small-scale expressed sequence tag analysis of Theileria uilenbergi: identification of a gene family encoding potential
antigenic proteins. Ann. N.Y. Acad. Sci., 1149: 214-217.(E-mail: [email protected])(Liu et al. describe the establishment of a cDNA library from the merozoite of Theileria uilenbergi and the quality assessment of this library by a ran-dom sequencing approach. Sequence alignment of three clones with a high identity to T. orientalis ToLocg 1 showed highly conserved but also variable regions, suggesting a gene family. Further PCR and sequencing analyses indicated that these clone-2 gene family members are tandemly arranged. Since these proteins were predicted to be apicoplast transmem-brane proteins containing a signal peptide cleavage site and antigenic determinants, clone-2 was recom-binantly expressed. Serum from Theileria (China)-infected animals showed immunoreactivity to this pro-tein, whereas serum from T. lestoquardi, B. motasi or A. ovis-infected animals showed no reactivity, thus this protein has the potential to be used for the development of a serological diagnostic tool. It remains to be investigated whether products of members of this gene family may be used to differentiate between the newly defined two species of Theileria infecting small ruminants in China, T. luwenshuni and T. uilenber-gi.) (US)
Chemotherapy
Lizundia R., Werling D., Langsley G. & Ralph S.A. 2009. Theileria apico-plast as a target for chemotherapy. Antimicrob. Agent Chemother., 53: 1213-1217.(E-mail: [email protected])(To examine whether in silico Theileria matches to Plasmodium and Toxoplasma drug targets represent potential chemotherapeutic targets, the authors tested compounds that target various apicoplast functions for their ability to inhibit Theileria-induced proliferation of parasitized B cells. The functions of these targets were DNA replication (ciprofloxacin), transcrip-tion (rifampin), translation (clindamy-acin), and isopentenyl diphosphate synthesis (fosmidomycin). Two fatty acid synthesis inhibitors: triclosan, which is thought to inhibit enoyl acyl carrier protein (ACP) reductase , and fenoxaprop, which is thought to inhibit acetyl coenzyme A (acetyl-CoA) car-boxylase, were also tested, although no
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enoyl ACP reductase or acetyl-CoA carboxylase is apparent in the Theileria genomes. The inhibition assays indicated that several putative inhibitors of apicoplast function inhibit Theileria-induced proliferation of lym-phocytes, but their modes of action are unclear. Ciprofloxacin appears to spe-cifically inhibit growth of Theileria-infected B cells without having any effect on uninfected B cells. Three other compounds, fenoxaprop, tri-closan (inhibitors of fatty acid synthe-sis), and rifampin (bacterial transcrip-tion inhibitor), inhibited proliferation of Theileria-infected lymphocytes, but this effect could not be separated or distinguished from their direct inhibi-tion of B-cell proliferation. The pro-posed targets of fenoxaprop and tri-closan in Plasmodium, the single-polypeptide-type acetyl-CoA carboxy-lase and enoyl ACP reductase, respec-tively, are absent in both Theileria and humans, so their mode of action can-not be via these enzymes.) (US)(GU: I’m not sure everyone knows the meaning of in silico. I confess that I had to look it up: = by computer simulation, as opposed to in vitro and in vivo.)
BABESIOSIS
Recent publications
Immunisation
Bautista C.R., Alvarez J.A., Mosqueda J.J., Falcon A., Ramos J.A., Rojas C., Figueroa J.V. & Ku M. 2008. Enhancement of the Mexican bovine babesiosis vaccine efficacy by using Lactobacillus casei. Ann. N.Y. Acad. Sci., 1149: 126-130. (E-mail:[email protected])(Two groups of cattle were vaccinated with babesiosis vaccine with and with-out prior inoculation of L casei, a known inducer of IL-12 and IFN-γ. A further 2 groups were unvaccinated controls injected with saline with and without L casei. Twenty four days later, all the animals were challenged with Babesia bovis and Babesia bigemina. Temperature and PCV were used to monitor the challenge reac-tions. There were no differences in the clinical reactions of the vaccinated groups but the group also injected L casei had significantly higher titres against B. bovis as measured by IFAT.
The unvaccinated controls were treated with a babesicide ‘to avoid their death’ but in fact, the temperatures were bare-ly above ‘normal’ (means of the con-trol groups were 38.9 and 39.1°C) and the PCVs were also in the normal range (group minimums of 33 and 32.8% respectively). It was therefore difficult to form an opinion on the pro-tective effect of the vaccine when the respective vaccinated groups had very similar temperatures (38.5°C in both groups) and PCVs only marginally higher than those of the controls (38.5 and 36.7%). The vaccine was devel-oped at the Instituto Nacional de Investigaciones Forestales, Agicolas y Pecuarias (INIFAP) consisted of B. bigemina (BIS clone) and B. bovis BOR strain). The authors concluded that L casei, inoculated 2 days before vaccination improved the vaccine’s efficacy.) (BdV)(GU: The conclusionof the authors is apparently debatable!)
Fish L., Leibovich B., Krigel Y., McElwain T. & Shkap V. 2008. Vaccination against B. bovis infection with live attenuated parasites and non-viable immunogens. Vaccine, 265 (Suppl. 6): G29-G33.(E-mail [email protected])(In this interesting study, groups of susceptible 6-9 month old dairy calves were immunised with Babesia bovis vaccines containing: Attenuated, live donor-derived para-sites passaged 15 times in splenect-omised calvesIn vitro-cultured, biologically cloned parasitesNon-viable culture-derived soluble exoantigens given twice at 21 day interval with saponin as adjuvantRecombinant rhoptry-associated pro-tein (rRAP1) given 3 times at 21 day intervals with Freund’s Complete Adjuvant (x1) and Freund’s incomplete adjuvant (x2) The donor-derived vaccine was not entirely safe and immunised calves developed fever and alarming decreas-es in packed cell volume. In contrast, in vitro-derived cloned organisms were completely avirulent. All the calves were then challenged with a virulent heterologous strain 6 weeks after the last vaccination and antibody respons-es assessed by IFAT before and after challenge. An in vitro inhibition assay was also performed on sera of immu-nised calves. Calves immunised with donor-derived live parasites or in vitro-
derived cloned parasites were solidly protected as were calves immunised with non-viable soluble antigen. Those immunised with rRAP1 showed high antibody titres but were poorly protect-ed and 50% required treatment after challenge. Antibody titres were highest after use of the calf-derived vaccine and sera from calves in all the groups inhibited growth in vitro.) (BdV: It is a pity the trial was not conducted under conditions where the immunity was subjected to a vigorous test. While dairy breeds are highly susceptible, calves aged under 9 months still have a degree of innate resistance and the challenge was per-formed when antibody titres would have been at a peak. Timms et al. (1983) also studied in vitro-derived antigen with saponin but used 2 year old cattle and found the protection to be disappointing when they were chal-lenged 70 days later. Having a non-living babesiosis vaccine is a long standing ideal in many countries but it must be able to protect even the most susceptible cattle and the immunity must be durable.)
Epidemiology/transmission
Lopez M., Figueroa J.V., Ramos J.A., Mosqueda J.J., Rojas E., Vega C.A. & Alvarez J.A. 2008. Infection and sero-conversion of susceptible animals introduced into a babesiosis endemic area. Ann. N. Y. Acad Sci., 1149: 131-135.(E-mail [email protected])(The aim of the study was to determine the incubation periods of Babesia bovis and Babesia bigemina infections in naïve cattle exposed to natural Boophilus microplus infestations at Veracruz, Mexico. The cattle (naïve 18-month old Bos taurus steers) were introduced at 3-monthly intervals over a 12 month period and monitored for clinical and serological responses. Climatic conditions were favourable for ticks throughout the study period. Tick infestations were heavy to very heavy with all the cattle becoming infected and having to be treated by day 20. This is a classic hyperendemic situation and the authors wisely con-cluded that introduction of naïve cattle into this region should be accompanied by strategic tick control and other pre-ventive measures such as vaccination (see paper by Bautista et al. (2008) on the use of a babesiosis vaccine in Mexico).) (BdV)
Schwint O.N., Knowles D.P., Ueti M.W., Kappmeyer L.S. & Scoles G.A. 2008. Transmission of Babesia caballi by Dermacentor nitens (Acari: Ixodidae) is restricted to one genera-tion in the absence of alimentary rein-fection on a susceptible equine host. J. Med. Entomol., 45:1152-1155.(E-mail: [email protected])(Partially engorged Dermacentor nitens ticks that fed on a B. caballi-infected horse were allowed to reattach on an uninfected horse and successful-ly transmitted the infection. The off-spring of these females were reared to test for B. caballi infection. The first generation successfully transmitted B. caballi, the second and third three sub-sequent generations on calves and a sample of the larvae from each genera-tion was fed on naïve horses genera-tion did not. This showed that infection of D. nitens with B. caballi was restricted to one generation in the absence of a new alimentary infec-tion.) (AN)
Population genetics
Borgonio V., Mosqueda J., Genis A.D., Falcon, A., Alvarez J.A., Camacho M..& Figueroa J.V. 2008. msa-1 and msa-2c gene analysis and common epitopes assessment in Mexican Babesia bovis isolates. Ann. N.Y. Acad. Sci., 1149: 145-148. (Email: [email protected])(The authors assessed the conservation of msa-1 and msa-2c within Mexican isolates of Babesia bovis using molec-ular and immunological methods. There was polymorphism of msa-1 in both the PCR fragment size and the DNA sequence. A monoclonal anti-body to MSA-1 used in immunoblot-ting did not react with 5 of the 12 Mexican isolates. With regard to MSA-2c, polyclonal antiserum pre-pared to full-length recombinant MSA-2c did not react with 4 of the 12 Mexican isolates (different isolates to those not recognised by the MSA-1 antibody) although comparative MSA-2c sequence analysis of the Mexican isolates indicated high homology. Unfortunately the author’s claim that MSA-2c antigen could be used as a diagnostic tool is not adequately sup-ported by the results presented in this paper.) (LJ)
Genis A.D., Mosqueda J.J., Borgonio V.M., Falcón A., Alvarez A., Camacho M., de Lourdes Muñoz M. & Figuero
J.V.2008. Phylogenetic analysis of Mexican Babesia bovis isolates using msa and ssrRNA gene sequences. Ann. N.Y. Acad. Sci., 1149: 121-125.(E-mail: [email protected])(The authors carried out an interesting population genetic study comparing the evolution of three msa genes and a more conserved 18S rRNA gene among Mexican populations of B. bovis. Additional isolates from Australia were included for global comparisons. The msa genes displayed low sequence identities (47.7 – 87.7%) and considerable diversity was meas-ured among the Mexican isolates. The authors suggest that despite the high level of divergence among isolates the lack of geographic structure observed might reflect different selection pres-sure on the msa genes and high cattle movements in Mexico. An additional factor not addressed by the authors is that third base codon position is likely saturated, particularly for deeper phyl-ogenetic comparisons with Australian isolates. Inferring evolutionary origins of B. bovis might be beyond the scope of this marker but the authors have made a good start on tracking the evo-lution of the msa genes in Mexico.) (JATM)
Wilkowsky S., Farber M., Gil G., Echaide I., Mosqueda J., Alcaraz E., Suarez C.E. & Florin-Christensen M. 2008. Molecular characterization of Babesia bovis strains using PCR restriction fragment length polymor-phism analysis of the msa2-a/b genes. Ann. N.Y. Acad. Sci., 1149: 141-144. (E-mail: [email protected])(A more straightforward study than that done by Genis et al. (same vol-ume, pp 121-125, presented above) using differences in the msa-2 genes to investigate strain differences among isolates from Argentina, the United States and Mexico. The authors have developed a simple assay with primers anchored in conserved sequences around the msa-2 gene. Once PCR amplified the gene was digested with the restriction enzyme BspMI that cuts the product into different length frag-ments depending on sequence differ-ences. Fragments were then separated by agarose gel electrophoresis or by PAGE. Strain-specific banding patterns were observed, even among different strains from Argentina although similar profiles could only be distinguished with the greater resolving power of PAGE. The assay provides a rapid
technique for differentiating American B. bovis isolates including the separa-tion of vaccine strains from pathogenic field isolates.) (JATM)
Diagnostics
Asenzo G., Wilkowsky S., Barrandeguy M., Mesplet M., Benitez D. & Florin Christensen M. 2008. Development of an indirect ELISA for the diagnosis of equine piroplasmosis. Ann. N.Y. Acad. Sci., 1149: 235-238. (E-mail: [email protected])(An indirect ELISA based on the equi merozoite antigen 1 (EMA-1) cloned from an Argentinean T. equi isolate was developed and used to screen 180 samples from two provinces in the north and east of Argentine. The results were quite similar to those obtained by a commercially available competitive ELISA.) (AN)
Harkirat Singh H., Mishra A.K., Rao R. & Tewari A.K. 2009. Comparison of indirect fluorescent antibody test (IFAT) and slide enzyme linked immu-nosorbent assay (SELISA) for diagno-sis of Babesia bigemina infection in bovines. Trop. Anim. Health Prod., 41: 153–159.(E-mail: [email protected])(The authors standardised an indirect fluorescent antibody test (IFAT) and slide enzyme linked immunosorbent assay (SELISA) for the detection of antibodies specific to Babesia bigemi-na in experimentally infected bovine calves and subsequently used for the screening of naturally infected bovine and bubaline sera. In experimentally infected calves positive reactivity was detected in sera at the earliest on day 7 by both the tests. Serological studies for detection of B. bigemina specific antibodies in 180 cow and 120 buffalo serum samples procured from endemic zones of Uttar Pradesh and Punjab revealed 56.11% and 23.33% seroposi-tivity, respectively, both by SELISA and IFAT. Variation in the reactivity pattern between these tests was found to be non significant. The sensitivity of SELISA was determined to be 94.85% whereas the specificity was 90.85% in comparison to IFAT. The agreement between the two tests by kappa statis-tics at 95% confidence interval revealed κ-value of 0.853 that depicts almost a perfect degree of agreement. The findings employing experimental as well as test sera from cattle and buf-falo from some of the tick infested
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zones of India suggested that SELISA could be a useful tool for seropreva-lence studies on babesiosis, as the test is less cost intensive with high levels of sensitivity and specificity.)(WJ: I certainly appreciate the chal-lenges of working in developing coun-tries – especially the difficulty in obtaining expensive reagents in the face of limited access to foreign exchange. However, it is very difficult to develop a serological test for B. bigemina with acceptable sensitivity and specificity. That is why so many variants have been published. The authors refer to and use IFAT method-ology from the 2004 OIE Manual where it is clearly stated that the B. bigemina IFAT has poor specificity. In addition, cross reactions with antibod-ies to B. bovis in the B. bigemina IFA test are a particular problem where the two parasites coexist. Comparing a test with poor sensitivity and specifici-ty with another is fraught with danger and in this case only demonstrates that both tests have poor sensitivity and specificity as the test results agreed. Although arduous, I recommend obtaining a bank of gold standard pos-itive and negative sera from the region in which the test is to be used as the starting point for validating a serologi-cal test. Critical review of the valida-tion methodology of the following paper may prove helpful: Goff W.L., Johnson W.C., Molloy J.B., Jorgensen W.K., Waldron S.J., Figueroa J.V., Matthee O., Adams D.S., McGuire T.C., Pino I., Mosqueda J., Palmer G.H., Knowles D.P. & McElwain T.F. 2008. Validation of a competitive ELISA for detection of Babesia bigemi-na antibodies in cattle. Clin. Vaccine Immunol., 15: 1316-1321.)
Petrigh R., Ruybal P., Thompson C., Neumann R., Moretta R., Wilkowsky S., Draghi G., Echaide I., de Echaide S.Torioni & Farber M. 2008. Improved molecular tools for detection of Babesia bigemina. Ann. N.Y. Acad. Sci., 1149: 155–157.(E-mail: [email protected])(One current method of molecular detection of Babesia bigemina involves a nested PCR protocol and reverse line blot hybridization (RLBH) assay based on the 18S gene. PCR is a powerful tool for epidemiologic inves-tigation of Babesia spp. infection in carrier animals on account of its high sensitivity and specificity. In this study, the authors developed a highly
specific and sensitive one-step PCR assay for the detection of Babesia bigemina using primers that amplify a 400-bp fragment within the conserved region of the five rap-1a paralogous genes. The specificity of the primers used in this study was determined by amplification of expected product from Babesia bigemina isolates, but no PCR products were detected when using DNAs from Babesia bovis, Anaplasma marginale and Anaplasma centrale. The test detection limit was 0.00002% PE. The authors state that the RLBH assay, with a new B. bigemina probe, allows the detection of all tested B. bigemina isolates showing no cross-hybridization with B. bovis 18S gene. By developing this highly specific and sensitive one-step PCR and upgrading the RLBH assay for B. bigemina, they claim to have improved molecular assays which, together with serologic methods, provide valuable tools for epidemiologic studies of bovine babe-siosis. In their introduction, the authors state that microscopic examination of blood smears is used for the diagnosis of acute Babesia infections, but its low sensitivity prevents detection of para-sites in subclinical infections.) (WJ: I disagree and suggest that the sensitivity of detection is dependant on the skills of the microscopist. B. bigemina is particularly easy to detect in thick blood films and this technique is almost as sensitive as PCR due to the volume of blood screened.)
Pathology
Saleh M. A. 2009. Erythrocytic oxida-tive damage in crossbred cattle natu-rally infected with Babesia bigemina. Res. Vet. Sci., 86: 43-48.(E-mail: [email protected])(The erythrocytic stage of Babesia bigemina in cattle causes severe symp-toms including anaemia and haemoglo-binuria. This study investigated lipid peroxidation and blood methaemoglo-bin as indicators of oxidative damage, as well as their role in erythrocytic fra-gility and anemia during B. bigemina infection in cattle. The author suggests that the severity of the disease is directly related to erythrocytic lipid peroxidation and haemoglobin oxida-tion. Furthermore that erythrocytic lipid peroxidation and haemoglobin oxidation contribute to anaemia. The oxidative changes in the erythrocyte membrane contribute to osmotic fragi-lity of the erythrocytes and intravascu-
lar hameolysis and contribute to the pathological consequences of B. bige-mina infection.) (LJ)
In vitro culture
Sánchez C., Campos E. & Oliva A.G. 2009. Babesia bovis: effect of Albumax II and orotic acid in a low-serum in vitro culture. Exp. Parasitol., 121: 274-278.(E-mail: clausl@[email protected])(This study examines the effects of bovine serum, Albumax II and orotic acid on the in vitro culture of a Babesia bovis biological clone. The effects of bovine serum and Albumax II have been studied previously by other groups, so the effects of orotic acid on the growth of B. bovis are novel. Orotic acid is involved in the de novo synthesis of pyrimidines by Babesia parasites and the addition of orotic acid to culture media did not significantly improve growth. Cytological characteristics of the B. bovis parasites grown under different culture conditions did not differ. The statistical reporting in this paper is incorrect in a number of places with no significance differences between treat-ments seen and yet a P value of <0.05 is given. One limitation with this study and other published reports of in vitro culture of Babesia parasites, is the ten-dency to use of one strain/clone rather than test numerous strains and to use culture-adapted strains rather than infected blood.) (LJ)
Molecular biology
Suarez C.E. & McElwain T.F.M. 2009). Stable expression of a GFP-BSD fusion protein in Babesia bovis merozoites. Int. J. Parasitol., 39: 289-297. (E-mail: [email protected])(Whilst previous studies have described the transient expression of foreign genes into Babesia bovis, this study describes the stable transfection of B. bovis. Based on Plasmodium research, stable transfection was achieved using a plasmid containing the gfp-bsd gene into the ef-1a locus. Transfected parasites were selected in in vitro culture using blasticidin and were examined by fluorescence microscopy, RT-PCR and immunoblotting to confirm continuous expression of the gfp-bsd gene. Blasticidin-resistant parasites were detected as early as 5 days after electroporation, but were not detected
in control cultures. These transfected parasites emitted high levels of GFP fluorescence over a period of 9 months and then routine microscopy was halted. Results of further experiments suggested that the transfection plasmid was integrated into the chromosome of the transfected parasites. This transfection protocol will be a useful tool for further research into all aspects of Babesia bovis.) (LJ)
Vichido R., Falcon A., Ramos J.A., Alvarez A., Figueroav J.V., Norimine J., Brown W.C., Castro L.A. & Mosqueda J. 2008.. Expression analy-sis of heat shock protein 20 and rhop-try-associated protein 1a in sexual stages and kinetes of Babesia bigemi-na. Ann. N.Y. Acad. Sci., 1149: 136-140. (E-mail: [email protected])(There is little information on Babesia parasites during the tick stage of their life cycle with regard to their molecu-lar, physiological and antigenic activi-ty. This paper is a good start to this process. Sexual stages from Babesia bigemina infected tick midguts and kinetes from tick haemolymph were studied for their expression of heat shock protein 20 (HSP-20) and rhop-try-associated protein 1a (RAP-1a). The authors demonstrated that hsp-20 and rap-1a are both transcribed in the sexual stages and kinetes. Immunofluorescence studies indicated that HSP-20 and RAP-1a can be detected in both sexual stages and kinetes and interestingly with differen-tial staining patterns for the stages. These results together with previous studies indicate that HSP-20 and RAP-1a are present throughout the life cycle of Babesia bigemina and could make good vaccine candidates and/or diag-nostic tools.) (LJ)
Small ruminants
Niu Q., Luo J., Guan G., Liu Z., Ma M., Liu A., Gao J., Ren Q., Li Y., Qiu J. & Yin H. 2009. Differentiation of two ovine Babesia based on the ribos-omal DNA internal transcribed spacer (ITS) sequences. Exp. Parasitol., 121: 64-68.(E-mail: [email protected])(Analysis of internal transcribed spacer (ITS) region sequences from six ovine Babesia isolates from different geo-graphical regions of China divided them into two distinct clusters. One contained five Babesia motasi isolates transmitted by Haemaphysalis spp., the
other a Babesia species referred to as Babesia sp. Kashi which is presumably transmitted by Hy. a. anatolicum (GU: now classified as a full species, Hyalomma anatolicum.)) (AN)
Horses
Bhoora R., Franssen L., Oosthuizen M.C., Guthrie A.J., Zweygarth E., Penzhorn B.L., Jongejan F. & Collins N.E. 2009. Sequence heterogeneity in the 18S rRNA gene within Theileria equi and Babesia caballi from horses in South Africa. Vet. Parasitol., 159: 112-120.(E-mail: [email protected])(A total of 488 samples from South African horses (471) and zebra (17) were screened for the presence of Babesia and Theileria species using Reverse Line Blot hybridization. Results indicated the presence of novel genotypes or species in this panel and the 18S rRNA from 33 samples was sequenced. Extensive variation was found in the V4 variable region of this gene from Theileria equi and to a less-er extent from Babesia caballi, so the authors cannot rule out the possibility that these in fact represent different parasite species. It is recommended that researchers wishing to use the 18S rRNA gene in molecular diagnostics tests first thoroughly map the intraspe-cific sequence divergence of the parasite(s) of interest.) (AN)
Karatepe B., Karatepe M., Cakmak A., Karaer Z. & Ergun G. 2009. Investigation of seroprevalence of Theileria equi and Babesia caballi in horses in Nigde province, Turkey. Trop. Anim. Health Prod., 41: 109-113. (E-mail: [email protected])(Serum samples from 125 randomly selected from Nigde Province, Turkey were screened by IFAT for antibodies against Theileria equi and Babesia caballi. Sixteen horses tested positive for T. equi, twelve for B. caballi and five horses tested positive for both par-asites.) (AN)
Water buffalo
Ferrreri L, Benitez D., Dominguez M., Rodriguez A., Asenzo G., Mesplet M., Florin-Christensen M. & Schnittger L. 2008. Water buffalos as carriers of Babesia bovis in Argentina. Ann. N.Y. Acad. Sci., 1149: 149-151. (E-mail: [email protected])(Efforts are being made to eradicate
Boophilus microplus in Argentina with established tick-free, obligatory eradi-cation and endemic areas. During the past decade, water buffalo (Bubalus bubalis) numbers have increased dra-matically in these areas and the aim of this study was to determine the poten-tial role of buffalo as hosts of Babesia bovis. A total of 103 buffalo were sam-pled on 4 properties, 2 in the eradica-tion area and 2 in the endemic area. The samples were analysed by nested PCR and cELISA, and the results showed 50 animals (about 50%) to be positive by either the one or the other test. Ticks were seen feeding on buffa-lo on one of the properties in the endemic area. There was no evidence of disease in the buffalo and the authors concluded quite rightly that the presence of these animals could impede efforts to eradicate the tick and its pathogen, and that these animals should be included in any eradication program.) (BdV)
Zoonoses
In NL n° 35 a short review was given on zoonotic Babesia spp. in European ruminants. The following publications are very relevant here:
Becker C.A.M., Bouju-Albert A., Jouglin M., Chauvin A. & Malandrin L. 2009. Natural transmission of zoonotic Babesia spp. by Ixodes rici-nus ticks. Emerg. Infect. Dis., 15: 320-322.(E-mail: [email protected])(The salivary glands from Ixodes rici-nus adult (presumably all female) ticks collected from roe deer and cattle were screened for the presence of Babesia spp. by microscopic examination. The 18S rRNA gene of positive samples was PCR amplified and sequenced and positive material was used to initiate in vitro cultures with. Three out of 223 ticks collected from cattle on a farm and 2 out of 31 ticks collected from roe deer in a wild fauna reserve were found positive for Babesia sp. EU1 while Babesia divergens was not observed in any of the salivary gland suspensions, even in those collected on the cattle, where infection by this spe-cies was common, as shown by other means. Development of intra-erythro-cytic Babesia sp. EU1 parasites was observed in the in vitro cultures using sheep erythrocytes.) (AN)(GU: The authors showed that the spo-rozoites of Babesia sp. EU1 (also
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known as B. venatorum) directly invade red cells of sheep in vitro (cat-tle erythrocytes were not invaded), thus classifying this species as a true Babesia (as the authors say, and which cannot be sufficiently stressed: this is a feature generally not proven for most Babesia spp). The fact that sporozoites of Babesia sp. EU1 did not invade cat-tle red cells, but were found in ticks collected on the cattle farm is intrigu-ing.)
Wielinga P.R., Fonville M., Sprong H., Gaasenbeek C., Borgsteede F. & Giessen J.W. 2008. Persistent detection of Babesia EU1 and Babesia microti in Ixodes ricinus in the Netherlands dur-ing a 5-Year surveillance: 2003-2007. Vector Borne Zoonotic. Dis., 9: 119-121. (E-mail: [email protected])(Ixodes ricinus ticks (n=1488) collected over five years from a dune forest area in the Netherlands were screened for Babesia infections using the Reverse Line Blot assay. The ticks harboured Babesia sp. EU1 (n=13), Babesia microti (n=2) and Babesia divergens (n=1).) (AN)
Various
Boldbaatar D., Battsetseg B., Matsuo T., Hatta T., Umemiya-Shirafuji R., Xuan X. & Fujisaki K. 2008. Tick vitellogenin receptor reveals critical role in oocyte development and transo-varial transmission of Babesia parasite. Biochem. Cell Biol. 86: 331-344. (E-mail: [email protected])(Excellent paper which describes the characterization and localization of a vitellogenin receptor from Haemaphysalis longicornis (HlVgR). RNA interference of this gene disrupt-ed egg development and oviposition. Babesia parasites could not be detected in the ovaries of HlVgR silenced females that had fed on a Babesia gib-soni infected dog in contrast to eggs of PBS and non-injected ticks, suggesting that HlVgR is essential in the transo-varial transmission of Babesia spp.)(AN)
Garcia-Sanmartin J., Barandika J.F., Juste R.A., Garcia-Perez A.L. & Hurtado A. 2008. Distribution and molecular detection of Theileria and Babesia in questing ticks from north-ern Spain. Med. Vet. Entomol., 22: 318-325.(E-mail: [email protected])(Ticks (n=562) collected from the veg-
etation in Basque country, Spain, were screened by Reverse Line Blot hybridi-zation (RLB) for the presence of Babesia and Theileria spp. Theileria spp. were found in 7.7% of the ticks, Babesia spp. in 3.0% and 1.4% of the ticks harboured species from both gen-era. Sixteen different piroplasm species were detected in total. Several new tick-pathogen associations were identi-fied, most notably that of Ixodes rici-nus with Theileria annulata. The authors correctly state that only trans-mission studies can prove whether these associations represent more than the detection of accidental carriers.) (AN)
ANAPLASMOSIS
Recent publications concerning research on anaplasmosis are high-lighted in this Section. We welcome short reviews related to current research topics, summaries of recent publications or epidemiologic findings. Please send your contributions for the ICTTD Newsletter to Dr. K. M. Kocan, at the address at the end of this issue. Files can also be received when attached to E-mail as a word file or text file. Thank you for your participa-tion in the Anaplasmosis Section of the ICTTD Newsletter.
Recent publications
Carelli G., Decaro N., Lorusso E., Paradies P., Elia G., Martella V., Buonavoglia C. & Ceci L. 2008. First report of bovine anaplasmosis caused by Anaplasma centrale in Europe. Ann. N.Y. Acad. Sci., 1149: 107-110. (E-mail: [email protected])(Anaplasma centrale (Rickettsiales: Anaplasmataceae) is used as a live vaccine for cattle against the pathogen-ic Anaplasma marginale in tropical and subtropical areas. Herein we report a clinical case of bovine anaplasmosis associated with A. centrale infection in Italy, together with the first molecular identification and phylogenetic analy-sis of this Anaplasma species or sub-species in Europe.) (KK)(GU: The authors do not indicate whether South African A. centrale has been used in Italy to immunise against anaplasmosis. If so, this could explain
the fact that the Italian isolates are related on the basis of 16S rDNA sequences to the South African vaccine strain, less to isolates of Japanese ori-gin. However, comparing groEL sequences, the Italian isolates are less related to African ones; no comparison to Japanese isolates was possible. It is known that the South African vaccine strain is less virulent than many A. marginale strains, but not completely devoid of virulence. The percentage of “marginal” and “central” (i.e. non-mar-ginal) anaplasms in the red cells is in any case not related to virulence (e.g. Japanese A. centrale is much more vir-ulent than South African A. centrale, some isolates of typical A. marginale are of much lower virulence than oth-ers, and there are virulent isolates in which only about 50% of the ana-plasms are peripheral and 50% “cen-tral”.)
Dark M.J., Herndon D.R., Kappmeyer L.S., Gonzales M.P., Nordeen E., Palmer G.H., Knowles D.P. Jr & Brayton K.A.. 2009. Conservation in the face of diversity: multistrain analy-sis of an intracellular bacterium. BMC Genomics. 10: 16.(E-mail: [email protected]) Open Access, published online.(BACKGROUND: With the recent completion of numerous sequenced bacterial genomes, notable advances have been made in understanding the level of conservation between various species. However, relatively little is known about the genomic diversity among strains. We determined the complete genome sequence of the Florida strain of Anaplasma marginale, and near complete (>96%) sequences for an additional three strains, for com-parative analysis with the previously fully sequenced St. Maries strain genome. RESULTS: These compari-sons revealed that A. marginale has a closed-core genome with few highly plastic regions, which include the msp2 and msp3 genes, as well as the aaap locus. Comparison of the Florida and St. Maries genome sequences found that SNPs comprise 0.8% of the longer Florida genome, with 33.5% of the total SNPs between all five strains present in at least two strains and 3.0% of SNPs present in all strains except Florida. Comparison of genomes from three strains of Mycobacterium tuber-culosis, Bacillus anthracis, and Nessieria meningiditis, as well as four Chlamydophila pneumoniae strains
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found that 98.8%-100% of SNPs are unique to each strain, suggesting A. marginale, with 76.0%, has an inter-mediate level of strain-specific SNPs. Comparison of genomes from other organisms revealed variation in diver-sity that did not segregate with the environmental niche the bacterium occupies, ranging from 0.00% to 8.00% of the larger pairwise-compared genome. CONCLUSION: Analysis of multiple A. marginale strains suggests intracellular bacteria have more varia-ble SNP retention rates than previously reported, and may have closed-core genomes in response to the host organ-ism environment and/or reductive evo-lution.) (KK)
de la Fuente J., Blouin E.F., Manzano-Roman R., Naranjo V., Almazán C., Pérez de la Lastra J.M., Zivkovic Z., Massung R.F., Jongejan F. Kocan K.M. 2008. Differential expression of the tick protective antigen subolesin in Anaplasma marginale- and A. phago-cytophilum-infected host cells. Ann. N.Y. Acad. Sci., 1149: 27-35. (E-mail: [email protected])(Subolesin was recently shown in vac-cine and RNA interference (RNAi) studies to protect against tick infesta-tions and to affect tick feeding, repro-duction, and development as well as infection of host cells by Anaplasma marginale and A. phagocytophilum. Recent experiments provided evidence that infection of both tick and verte-brate host cells with these two patho-gens modified gene expression. We therefore hypothesized that infection of host cells with A. marginale and A. phagocytophilum affects expression of subolesin. Subolesin mRNA levels were determined by real-time reverse transcriptase (RT)-PCR in uninfected and A. marginale-infected Dermacentor variabilis guts and sali-vary glands and IDE8-cultured tick cells and in uninfected and A. phago-cytophilum-infected Ixodes scapularis nymphs, ISE6-cultured tick cells, and the human cell line HL-60. In addition, the effect of subolesin on Anaplasma spp. infection/multiplication was char-acterized by RNAi in tick tissues and/or cultured tick and human cells. These experiments presented evidence of dif-ferential expression of subolesin in A. marginale- and A. phagocytophilum-infected cells. Subolesin was differen-tially expressed in A. marginale-infect-ed ticks in a tissue-specific manner in which mRNA levels increased in
response to A. marginale infection in tick salivary gland cells but not in the gut cells. Subolesin knockdown by RNAi reduced Anaplasma infection/multiplication only in cells in which infection increased subolesin expres-sion, i.e., in A. marginale-infected D. variabilis salivary glands and IDE8 cells. The results reported herein fur-ther support the role of subolesin in Anaplasma-host interactions and sug-gest a putative role of subolesin in vac-cines for the control of pathogen infec-tion/multiplication in ticks.) (KK)
Esteves E., Bastos C.V., Zivkovic Z., de la Fuente J., Kocan K., Blouin E., Ribeiro M.F., Passos L.M. & Daffre S. 2009. Propagation of a Brazilian iso-late of Anaplasma marginale with appendage in a tick cell line (BME26) derived from Rhipicephalus (Boophilus) microplus. Vet. Parasitol., 161: 150-153.(E-mail: [email protected])(Anaplasma marginale is a tick-borne pathogen of cattle responsible for the disease anaplasmosis. Data suggest that Rhipicephalus (Boophilus) micro-plus and R. annulatus may be the major tick vectors of A. marginale in tropical and subtropical regions of the world. (GU: and also Boophilus decol-oratus!) In this work we demonstrated the first infection and propagation of a Brazilian isolate of A. marginale (UFMG1) in the BME26 cell line derived originally from embryos of R. (Boophilus) microplus. The establish-ment of A. marginale infection in a cell line derived from R. (Boophilus) microplus is relevant for studying the A. marginale/tick interface.) (KK)
Fyumagwa R.D., Simmler P., Meli M.L., Hoare R., Hofmann-Lehmann R. & Lutz H. 2009. Prevalence of Anaplasma marginale in different tick species from Ngorongoro Crater, Tanzania. Vet. Parasitol., 161: 154-157. (E-mail: [email protected])(In 2001, Ngorongoro Crater was infested with high density of ticks on grassland, livestock and wildlife which was also associated with high mortali-ty. Adult ticks were collected, identi-fied, processed for nucleic acids extraction and a molecular analysis was performed to determine the range of tick species harboring Anaplasma marginale. The real-time PCR was used in the amplification of rickettsia DNA in tick pools (n=527) from 11 identified tick species. Six tick species
were detected with A. marginale DNA including Amblyomma gemma, Rhipicephalus appendiculatus, R. com-positus, R.decoloratus, R. praetextatus and R. pulchellus. The detection rate in each tick species was 3%, 0.7%, 2%, 13%, 1.8%, and 6.2%, respectively. Five of the positive tick species excluding R. decoloratus have previ-ously not been described to transmit A. marginale. High diversity of tick spe-cies detected with A. marginale in Ngorongoro Crater is likely to increase a risk to susceptible animals of con-tracting the infection.) (KK) (GU: Harbouring A. marginale (or any other pathogen) is no proof of trans-mission!)
Galletti M.F., Ueti M.W., Knowles D.P. Jr, Brayton K.A. & Palmer G.H.. 2009. Independence of Anaplasma marginale strains with high and low transmission efficiencies in the tick vector following simultaneous acquisi-tion by feeding on a superinfected mammalian reservoir host. Infect. Immun., 77: 1459-1464. (E-mail: [email protected]) (Strain superinfection occurs when a second pathogen strain infects a host already carrying a primary strain. Anaplasma marginale superinfection occurs when the second strain carries a variant repertoire different from that of the primary strain, and the epidemio-logic consequences depend on the rela-tive efficiencies of tick-borne transmis-sion of the two strains. Following strain superinfection in the reservoir host, we tested whether the presence of two A. marginale (sensu lato) strains that differed in transmission efficiency altered the transmission phenotypes in comparison to those for single-strain infections. Dermacentor andersoni ticks were fed on animals superinfect-ed with the Anaplasma marginale subsp. centrale vaccine strain (low transmission efficiency) and the A. marginale St. Maries strain (high transmission efficiency). Within ticks that acquired both strains, the St. Maries strain had a competitive advan-tage and replicated to significantly higher levels than the vaccine strain. The St. Maries strain was subsequently transmitted to naïve hosts by ticks pre-viously fed either on superinfected ani-mals or on animals singly infected with the St. Maries strain, consistent with the predicted transmission pheno-type of this strain and the lack of inter-ference due to the presence of a com-
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peting low-efficiency strain. The vac-cine strain was not transmitted by either singly infected or coinfected ticks, consistent with the predicted transmission phenotype and the lack of enhancement due to the presence of a high-efficiency strain. These results support the idea that the strain pre-dominance in regions of endemicity is mediated by the intrinsic transmission efficiency of specific strains regardless of occurrence of superinfection.) (KK)(GU: As the vaccine strain was appar-ently not transmitted by Dermacentor andersoni, can one speak of “low transmission efficiency”? The only tick species that has been shown so far to be a vector of the vaccine strain is Rhipicephalus simus, and the South African experiment has never been confirmed.)
Kocan K.M., de la Fuente J., Manzano-Roman R., Naranjo V., Hynes W.L. & Sonenshine D.E. 2008. Silencing expression of the defensin, varisin, in male Dermacentor variabi-lis by RNA interference results in reduced Anaplasma marginale infec-tions. Exp. Appl. Acarol., 46: 17-28. (E-mail:[email protected])(Full reference of a publication given as Epub ahead of print in NL n° 37.)
Mingala C.N., Konnai S., Cruz L.C., Onuma M. & Ohashi K. 2009. Comparative moleculo-immunological analysis of swamp- and riverine-type water buffaloes responses. Cytokine,. Mar 12. [Epub ahead of print]. (E-mail: [email protected])(This moleculo-epidemiological and immunological study through cytokine response assessment was done to know the dynamics of cytokines in the initia-tion, persistence and association to physiological changes of a particular pathogen in water buffaloes. This is important to understand the magnitude and behavior of disease progression. Water buffalo blood samples gathered from different places in the Philippines revealed a 9.4%, 27.6%, 10.3% and 4.4% prevalence of bovine viral diarrhea virus (BVDV), bovine leuke-mia virus (BLV), Anaplasma margin-ale and Babesia bigemina infection, respectively. (GU: The abstract does not say how this prevalence was deter-mined.) This was the first surveillance study of BVDV and BLV in the coun-try. Furthermore, cytokine expression of these naturally infected animals was
also quantified. BVDV-infected ani-mals had up-regulated expressions of TNFα, IL-2 and IL-4; and down-regu-lated expressions of IFNγ and IL-12p40 while BLV positive animals had an up-regulated IL-4 and IL-6, and highly expressed IL-10 and IL-12p40 with unchanged IFNγ expression. Meanwhile, animals infected with A. marginale had all interleukins and IFNγ up-regulated with significant expression of IL-10 and IL-12p40 sim-ilar to the BLV positive animals. Since it was also observed that swamp-type buffaloes were more disease tolerant than riverine-type buffaloes based on the gathered infection rate of each examined pathogen, further assessment was done focusing on the two vital cytokines, IFNγ and TNFα. We quanti-fied IFNγ and TNFα expressions in ConA-stimulated PBMC from both swamp and riverine buffaloes by real-time PCR. Cytokine expression from ConA-stimulated PBMC revealed that both IFNγ and TNFα were more high-ly expressed in swamp than in riverine buffalo. To further examine the proba-ble cause of expression differences, the proximal promoter region of these two cytokines were sequenced for the pres-ence of nucleotide polymorphism fol-lowed by luciferase assay to analyze the effect of these polymorphisms in gene transcription. A single nucleotide polymorphism was found in the IFNγ(-299) while eight polymorphisms in the TNFα promoter (-541, -553, -562, -596, -609, -655, -659, -688). Luciferase assay showed that both IFNγ promoter and TNFα promoter in swamp-type water buffalo had higher transcription activity compared to riv-erine-type water buffalo. These find-ings confirm that IFNγ and TNFα tran-scriptions in these animals were highly affected by the disparity in the cytokine promoter region. This sug-gests that disease tolerance or suscepti-bility of these buffaloes could be due to the differences in their relative cytokine transcription and may relate to pathogen-host specific pathogene-sis.) (KK)
Moretta R., Ruybal P., Mesplet M., Petrigh R., Nuñez P., Gil G., Wilkowsky S., Garbossa G. & Farber M. 2008. Flow cytometry to evaluate Anaplasma marginale parasitemia using a fluorescent nucleic acid stain. Ann. N.Y. Acad. Sci., 1149: 111-113. (E-mail: [email protected])(In this work we describe a flow
cytometry-based method using SYTO16 (a DNA intercalating agent) to quantify Anaplasma marginale-infected erythrocytes in blood from bovine animals. The linearity and reproducibility of the results obtained with SYTO16 labeling followed by flow cytometry analysis make it a suit-able approach for measurement of par-asitemia in A. marginale infections.) (KK)
Ooshiro M., Zakimi S., Matsukawa Y., Yafuso M., Katagiri Y. & Inokuma H. 2009. Anaplasma marginale infection in a Japanese Black cow 13 years after eradication of Rhipicephalus (Boophilus) microplus in Okinawa, Japan. Vet. Parasitol., 160: 351-355. (E-mail: [email protected])(In October 2007, a 15-year-old Japanese Black cow on Ishigaki Island, Okinawa, Japan, was diagnosed with Anaplasma marginale infection based on clinical symptoms, blood examination, smear observation, 16S rRNA and groEL gene sequence analysis, and the result of a CF test. The cow was introduced into the farm from mainland Japan as a calf in 1993, one year before the eradication of Rhipicephalus (Boophilus) microplus, the main vector of A. marginale in Okinawa Prefecture. It is possible that the cow was first infected with A. marginale as a calf in Ishigaki Island and had been persistently infected since then. This is the first reported clinical case of A. marginale infection of cattle since the eradication of R. microplus in Okinawa Prefecture. Additional analysis of major surface protein 1α amino acid sequences revealed that the A. marginale Okinawa strain presented four new repeat forms which were not seen in other strains. This indicates that the Okinawa strain may be a unique geographical variant of A. marginale.) (KK)
Rodríguez Camarillo S.D., García Ortiz M.A., Rojas Ramírez E.E., Cantó Alarcón G.J., Preciado de la Torre J.F., Rosario Cruz R., Ramos Aragón J.A. & Aboytes Torres R. 2008. Anaplasma marginale Yucatan (Mexico) strain. Assessment of low virulence and potential use as a live vaccine. Ann. N.Y. Acad. Sci., 1149: 98-102. (E-mail: [email protected])(Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the virulence of this
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isolate by experimental inoculation of 113 susceptible cattle at increasing doses, after which only one animal required treatment for clinical disease. Subsequently, 104 cattle received a live vaccine of this strain by inoculation, which induced immunoprotection after heterologous challenged exposure with a different A. marginale isolate. In this study 14% of the immunized cattle required treatment as compared with the control nonimmunized cattle, in which 56% required treatment. The A. marginale vaccine strains used for the immunization studies had MSP1a variable regions that were different from those used for the challenge exposure.) (KK)
Ruybal P., Moretta R., Perez A., Petrigh R., Zimmer P., Alcaraz E., Echaide I., Torioni de Echaide S., Kocan K.M., de la Fuente J. & Farber M. 2009. Genetic diversity of Anaplasma marginale in Argentina. Vet. Parasitol., Feb 12. [Epub ahead of print].(E-mail: [email protected])(Bovine anaplasmosis caused by Anaplasma marginale is a worldwide major constraint to cattle production. The A. marginale major surface pro-tein 1 α (msp1α) gene contains a vari-able number of tandem repeats in the amino terminal region and has been used for the characterization of patho-gen genetic diversity. This study reports the first characterization of A. marginale genetic diversity in Argentina based on msp1α genotypes and its putative relationship with Rhipicephalus (Boophilus) microplus infestations. Herein, we analyzed whole blood bovine samples from ana-plasmosis outbreaks in R. microplus infested (9 samples) and eradicated/free (14 samples) regions. Sequence analysis revealed the existence of 15 different msp1α genotypes with 31 dif-ferent repeat units. Six new repeat sequences were discovered in this study and 13/31 (42%) repeats were unique to Argentinean strains. The analysis of msp1α repeat sequences according to R. microplus infestations resulted in three repeat groups: (i) found in tick-infested regions (20 repeats), (ii) found in tick free regions (6 repeats) and (iii) randomly distribut-ed (5 repeats). Moreover, A. marginale msp1α genetic diversity was higher in tick-infested regions than in tick free areas. These results, together with pre-
vious evidence suggesting that A. mar-ginale msp1α repeat units co-evolved with the tick vector, might represent an evidence of the role of tick-mediated transmission for the generation of pathogen genetic diversity.) (KK)
Rymaszewska A. & Grenda S. 2008. Bacteria of the genus Anaplasma - characteristics of Anaplasma and their vectors: a review. Veterinarni Medicina- Czech., 53: 573-584. Open access.(A general review of Anaplasma spp., including those transferred from the genus Ehrlichia, and their vectors. Useful as a first introduction, but of limited interest to tropical livestock, for example Boophilus ticks, important as vectors of erythrocytic anaplasmo-sis, particularly in the tropics, are not even mentioned.) (GU)
Shkap V., Kocan K., Molad T., Mazuz M., Leibovich B., Krigel Y., Michoytchenko A., Blouin E., de la Fuente J., Samish M., Mtshali M., Zweygarth E., Fleiderovich E.L. & Fish L. 2009. Experimental transmis-sion of field Anaplasma marginale and the A. centrale vaccine strain by Hyalomma excavatum, Rhipicephalus sanguineus and Rhipicephalus (Boophilus) annulatus ticks. Vet. Microbiol. , 134: 254-260. (E-mail: [email protected]) (Full reference of a publication given as Epub ahead of print in NL n° 38.)
Tamekuni K., Kano F.S., Ataliba A.C., Marana E.R., Venâncio E.J., Vidotto M.C., Garcia J.L., Headley S.A. & Vidotto O. 2009. Cloning, expression, and characterization of the MSP1a and MSP1b recombinant proteins from PR1 Anaplasma marginale strain, Brazil. Res. Vet. Sci., 86: 98-107. (E-mail: [email protected])(Full reference of a publication given as Epub ahead of print in NL n° 37.)
Torina A., Alongi A., Naranjo V., Scimeca S., Nicosia S., Di Marco V., Caracappa S., Kocan K.M. & de la Fuente J. 2008. Characterization of Anaplasma infections in Sicily, Italy. Ann. N.Y. Acad. Sci., 1149: 90-93. (E-mail:[email protected])(This study aimed to characterize infection with Anaplasma marginale, A. phagocytophilum, A. ovis, and A. platys in humans, animals, and ticks in Sicily, Italy, during 2003-2006.
Serologic (competitive ELISA [cELI-SA]) and indirect immunofluorescence antibody [IFA]; N= 1990) and DNA (polymerase chain reaction [PCR]; N= 2788) tests were conducted on horse, donkey, cattle, sheep, goat, pig, dog, cat, roe deer, wild boar, human, and tick samples. The results reported herein suggested that in Sicily cattle are a major reservoir for A. marginale, dogs for A. platys, and sheep and goats for A. ovis. Domestic animals, such as cattle, horses, donkeys, sheep, dogs, and cats, may serve as reservoir for A. phagocytophilum, but different strains may infect ruminants and humans. All Anaplasma spp. characterized in Sicily had some distinctive genotypes for this region. Low genetic diversity was observed in A. ovis and A. platys, whereas A. marginale and A. phagocy-tophilum strains showed high genetic diversity. These results expanded our knowledge about the prevalence of Anaplasma spp. in Sicily and provided information to understand the epidemi-ology of these infections and imple-ment measures to diagnose, treat, and control transmission to humans and animals in this region.) (KK)
Ueti M.W., Knowles D.P., Davitt C.M., Scoles G.A., Baszler T.V. & Palmer G.H. 2009. Quantitative differences in salivary pathogen load during tick transmission underlie strain-specific variation in transmission efficiency of Anaplasma marginale. Infect. Immun., 77: 70-75.(E-mail: [email protected])(Full reference of a publication given as Epub ahead of print in NL n° 38.)
Urdaz-Rodríguez J.H., Fosgate G.T., Alleman A.R., Rae D.O., Donovan G.A. & Melendez P. 2009. Seroprevalence estimation and man-agement factors associated with high herd seropositivity for Anaplasma marginale in commercial dairy farms of Puerto Rico. Trop. Anim. Health Prod., Apr 1. [Epub ahead of print]. (E-mail: [email protected])(A cross-sectional study was conducted to determine individual cow seropreva-lence of Anaplasma marginale in adult lactating dairy cattle of Puerto Rico (PR) and to assess the associations of farm management factors on herd sero-prevalence. Antibody activity against A. marginale was determined using the MSP-5 competitive enzyme-linked immunosorbent assay. Serum samples were obtained from 2,414 adult lacta-
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ting dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 3 to 100% with an overall individual cow seropre-valence for A. marginale of 27.4%. Factors associated with high herd sero-positivity were pasture grazing as the main feed source (OR = 6.5, 95% CI = 1.2-34), observed monkeys on the pre-mises (OR = 13, 95% CI = 1.2-138), use of 11% permethrin (OR = 17, 95% CI = 2.2-129), farmers who attended an acaricide certification program (OR = 0.18, 95% CI = 0.04-0.74), and lack of a fly control program (OR = 5.6, 95% CI = 1.3-24.) (KK)
EHRLICHIOSIS
Recent publications
delos Santos J.R.C., Oglesbee M., Rikihisa Y. & Stich R.W. 2008. Pathological evidence of ehrlichiosis in calves inoculated with Ehrlichia chaffeensis. Ann. N.Y. Acad. Sci., 1149: 103-106.(E-mail: [email protected])(For veterinarians it is of particular interest that calves not only can be infected with E. chaffeensis, but that they may succumb to the infection. Three of 6 calves inoculated i.v. with cultured cells infected with different isolates of E. chaffeensis died 6 to 13 days after the inoculation, and another one recovered after showing disease symptoms. Controls injected with non-infected cells did not show any clinical signs. For human medicine the main interest is the use of calves as an immunocompetent model for human monocytic ehrlichiosis.) (GU)
Ganta R.R., Peddireddi L., Seo G.M., Dedoner S.E., Cheng C. & Chapes S.K. 2009. Molecular characterization of Ehrlichia interactions with tick cells and macrophages. Front. Biosci., 14: 3259-3273.(E-mail: [email protected])(A review. Authors’ abstract: Several tick-transmitted Anaplasmataceae fam-ily rickettsiales of the genera Ehrlichia and Anaplasma have been discovered in recent years. Some species are clas-sified as pathogens causing emerging diseases with growing health concern for people. They include human mono-cytic ehrlichiosis, human granulocytic ewingii ehrlichiosis and human granu-
locytic anaplasmosis which are caused by Ehrlichia chaffeensis, E. ewingii and Anaplasma phagocytophilum, respectively. Despite the complex cel-lular environments and defense sys-tems of arthropod and vertebrate hosts, rickettsials have evolved strate-gies to evade host clearance and per-sist in both vertebrate and tick host environments. For example, E. chaf-feensis growing in vertebrate macro-phages has distinct patterns of global host cell-specific protein expression and differs considerably in morpholo-gy compared with its growth in tick cells. Immunological studies suggest that host cell-specific differences in Ehrlichia gene expression aid the pathogen, extending its survival. Bacteria from tick cells persist longer when injected into mice compared with mammalian macrophage-grown bacte-ria, and the host response is also sig-nificantly different. This review presents the current understanding of tick-Ehrlichia interactions and impli-cations for future.)
Kiel J.L., Gonzalez Y., Parker J.E., Andrews C., Martinez D., Vachiéry N. & Lefrançois Th. 2008. Viral associa-tion with the elusive rickettsia of viper plague from Ghana, West Africa. Ann. N.Y. Acad. Sci., 1149: 318-321. (E-mail:[email protected])(In an earlier paper (see NL n° 32, pp. 30-31) the group found a rickettsial organism closely related to, but appar-ently different from, E. ruminantium. Things are perhaps even more compli-cated, as coinfection with a retrovirus is now reported. As noted in a com-ment on the first paper, Aponomma latum is now classified as Amblyomma latum. Lots of research on E. ruminan-tium and related organisms in perspec-tive!) (GU)
See also in the section ANAPLASMOSIS.
COWDRIOSIS
Recent publications
Pedregal A., de Sousa D.R., Nguyen H.N., das Neves E.A., Lowagie S., Marique Th., Kagye N., Guerra I.T., Kamba Y., Totté Ph., Vachiéry N., Lefrançois Th., Martinez D.,
Yourassowsky C., Callens N., Monnom O., Dubois F. & Wérenne J. 2008. Toward prevention of cowdrio-sis. A closer look with the digital holo-graphic microscope 25 years after a first study of the IFN system in the bovine species. Ann. N.Y. Acad. Sci., 1149: 286-291. (E-mail:[email protected] [John Wérenne])(A technical paper on the mass produc-tion of E. ruminantium (ER) in cul-tured endothelial cells in bioreactors. Interferon (IFN-α and IFN-γ) has been shown to play an important role in pro-tection against heartwater. Endogenously induced IFN may lower ER mass production in cultures, and selection of the cell system may be important. A digital holographic micro-scope was superior to optical micros-copy for following the infection and the cytopathogenic effect in culture.) (GU)
Vachiéry N., Jeffery H., Pegram R., Aprelon R., Pinarello V., Kandassamy R.L.Y., Raliniaina M., Molia S., Savage H., Alexander R., Frebling M., Martinez D. & Lefrançois T. 2008. Amblyomma variegatum ticks and heartwater on three Caribbean islands. Tick infection and Ehrlichia ruminan-tium genetic diversity in bovine herds. Ann. N.Y. Acad. Sci., 1149: 191-195. (Animal biodiversity and emerging diseases: prediction and prevention. Proc. 9th Conf. of STVM, Merida, Mexico, Sparagano O.A.E., Maillard J.-Ch. & Figueroa J.V. (eds).) E-mail: [email protected].)(The authors’ abstract gives an excel-lent summary of the paper: “Amblyomma variegatum tick infesta-tion, tick infection by Ehrlichia rumi-nantium (ER), and ER genetic diversity were studied in the Caribbean Islands of Guadeloupe, Marie-Galante, and Antigua between 2003 and 2005. Nested PCR for pCS20 was used to detect ER, while ER strains were char-acterized by sequencing or by restric-tion fragment length polymorphism (RFLP) profiles of map-1 PCR prod-ucts. In 2003 in Guadeloupe, the prev-alence of tick-infested herds was 35.6%. In Marie-Galante 79.1% of herds in 2003 and 73.8% in 2005 were infested, while only an average of 2.2% of the herds were infected in Antigua between this same period. In Marie-Galante, 19.1% of ticks were ER positive, and ER-infected ticks were found in 33.3% of the herds. In Antigua only 5.8% of the ticks were ER
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positive. High ER tick infection rate combined with a very high level of tick infestation highlight the risk of heart-water in Marie-Galante and Guadeloupe more than in Antigua. The three islands still represent a reservoir for tick and heartwater in the Caribbean. Nine different African and Caribbean map-1 ER genotypes were identified. This diversity was observed even in restricted areas, and identical map-1 genotypes were observed on all three islands. This high genetic diver-sity of ER strains suggests that there was a simultaneous introduction of several strains from African countries into the Caribbean region.”) (GU: What is also interesting is the fact that the authors found a high genetic diversity of ER strains in the islands, even in restricted areas. Nine different map-1 genotypes were detected, 7 of which correspond to known genotypes in Africa. Whether or not these were all simultaneously introduced from Africa, or whether later mutations might also be involved, the diversity is in any case a major complication for vaccination against heartwater.)
Zweygarth E., Josemans A.I. & Steyn H.C. 2008. Experimental use of the attenuated Ehrlichia ruminantium (Welgevonden) vaccine in Merino sheep and Angora goats. Vaccine, 26 (Suppl. 6): G34-G39. (E-mail: [email protected])(Cryopreserved elementary bodies of the Welgevonden stock, attenuated in culture as reported earlier, were titrated in Merino sheep injected I.V. Its effica-cy depended on the number of living organisms in the immunising dose. Vaccination with a dose which did not cause disease apart from temperature reactions, gave full protection against virulent needle challenge 3 or 6 months later, without any temperature reactions on challenge. Most of the animals chal-lenged after 12 months developed tem-perature reactions, but only 1 in 5 had to be treated. Subcutaneous and intra-muscular immunisation also gave satis-factory results. The attenuated Welge-vonden stock was unexpectedly viru-lent in Angora goats, and treatment was necessary in some, although much less virulent than the current blood-based vaccine (using the Ball3 stock); full protection was obtained against viru-lent homologous needle challenge.)(GU: The efficacy of the attenuated Welgevonden stock against homolo-gous tick-borne challenge and field
challenge still remains to be shown. See also NL n° 38, p. 22.)
OTHER DISEASES
Tick-borne encephalitis
This is a zoonotic human viral (Flaviviridae) disease, not affecting tropical livestock, but there are more and more cases diagnosed in Europe, and it is certainly desirable that work-ers on TBDs of livestock have some inkling of what goes on in this field. Here is a brief summary based on a recent Pro-MED-mail (1st of February 2009), partly based on a news report from experts of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE). Ticks (Ixodes spp. are vectors, I. rici-nus being the main one in Europe) infected with the (European) TBE virus were detected in 2008 at more than 1500 meters above sea level, one of the consequences of global warm-ing. The ISW-TBE has been calling for vaccination against TBE to become a standard preventive measure for every-body travelling to endemic regions. TBE affects the central nervous system (and/or the meninges). The symptoms (in those cases where nervous symp-toms occur, about one-third of infected patients) range from minor neurologi-cal dysfunction to impaired concentra-tion, depression, severe paralysis, or even death. Since 1990, more than 157 500 cases of TBE have been registered in Europe, corresponding to 8755 cases annually. Once infected, there is no [specific] treatment available. Because vaccination coverage in Austria is exceptionally high, the number of TBE cases has come down from 677 in 1979 to 86 in 2008. The main hosts are small rodents, with humans being accidental hosts. Person-to-person transmission has not been reported. (There are other closely related viruses in this group. In Far Eastern Eurasia, Russian spring-summer encephalitis virus (RSSEV), is responsible for a similar disease with a more severe clinical course.) Based on ProMED mail (with addi-tions in italics)
More on CCHF
According to an authority in Russia the increase in incidence of Crimean-Congo hemorrhagic fever has been facilitated by the increase of veg-etation as a consequence of a decline in sheep rearing and grazing in the Southern Federal District. He also stated that virus circulation has risen because of high temperatures during the spring months in recent years. During the past 10 years, 1217 people contracted Crimean-Congo hemor-rhagic fever in the Southern Federal District, 60 of whom died (4.9%). 212 cases were registered in South Russia in 2008, including 12 fatalities (5.6%). The number of cases in 2008 increased by 52% in the Rostov region and by 26% in the Stavropol region, compared to 2007. More than 90% of cases were rural residents, who worked in animal husbandry, in gar-dens, or in the fields. The urban popu-lation contracted infection during vis-its to the countryside. In most cases infection was the result of tick bites or removal of ticks with bare hands. High rates of tick infestation have occurred in the early autumn of 2008, and epidemic development of the dis-ease should be expected in 2009. Rostov and Stavropol regions had the highest rates of the disease in the Southern Federal District in 2008. Dynamics of the years since 2004 indicate a steadily worsening situation in these regions. The statistics (which may not be very accurate) are: for Rostov region in 2004 - 9 cases; 2005 - 16; 2006 - 53; 2007 - 53; 2008 - 81; for Stavropol region in 2004 - 28; 2005 - 38; 2006 - 41; 2007 - 63; 2008 - 80.)
From ProMED-mail
(GU: Southern Federal District is not all that far from Turkey where there has been a considerable increase in cases in the past few years.)
Recent publications
Martins J.R., Leite R.C. & Doyle R.L. 2008. Tripanosomatids like Trypanosoma theileri in the cattle tick Boophilus microplus. Rev. Bras. Parasitol. Vet., 17: 113-114. (E-mail: [email protected])(Another finding of T. theileri-like trypanosomes in ticks, in the haemo-
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lymph. The ticks were female B. micro plus, fed on cattle. The trypa-nosomes were in epimastigote forms, and were not seen in eggs from these females.) (GU)
Mura A., Masala G., Tola G., Satta G., Fois F., Piras P., Rolain J.-M., Raoult D. & Parola P. 2008. First direct detec-tion of rickettsial pathogens and a new rickettsia, ‘Candidatus Rickettsia bar-bariae’, in ticks from Sardinia, Italy. Clin. Microbiol. Infect., 14: 1028-1033.(E-mail: [email protected])(Not of direct relevance to tropical livestock, but it is worthwhile to real-ise that many other rickettsial species and candidate species than R. conorii may be responsible for Mediterranean spotted fever in humans. There are useful phylogenetic trees of rickettsial organisms. ‘Candidatus Rickettsia bar-bariae’ was found in Rhipicephalus turanicus, but its pathogenicity is as yet unknown. It was first provisionally and incompletely described recently in Portugal.) (GU)
Rowlands R.J., Michaud V., Heath L., Hutchings G., Oura Ch., Vosloo W., Dwarka R., Onashvili T., Albina E. & Dixon L.K. 2008. African swine fever
virus isolate, Georgia, 2007. Emerg. Infect. Dis., 14: 1870-1874.(Amplified DNA fragments of this Caucasian isolate were sequenced and compared to other isolates. The Georgia isolate is closely related to a genotype (of the 22 genotypes identi-fied so far) circulating in Mozambique, Madagascar and Zambia. It is possible that the infection was brought in from southern Africa or Madagascar on ships through swill feeding or dumped port waste.) (GU. ASF is now a problem in many areas of the Caucasus, including Russia.)
Sanders D.M., Parker J.E., Walker W.W., Buchholz M.W., Blount K. & Kiel J.L. 2008. Field collection and genetic classification of tick-borne rickettsiae and rickettsiae-like patho-gens from South Texas: Coxiella bur-netii isolated from field-collected Amblyomma cajennense. Ann. N.Y. Acad. Sci., 1149: 208-211.(E-mail: [email protected])(Coxiella burnetii was isolated from A. cajennense nymphs and adults, reportedly for the first time in North America, where C. burnetii has been found in other tick species.)
ANNOUNCEMENTS
10th Biennial Conference STVM
In NL n° 36 it was announced that the next conference of the Society for Tropical Veterinary Medicine will be held in 2009 in Germany and that more information would soon be forth-coming. I hope those of you who are members of STVM have been directly informed in the meantime, or have taken the information from the STVM website (www.soctropvetmed.org), as this issue of the NL will reach you too late, because the conference will be held from June 29 to July 3, 2009, in Lübeck, Germany. My apologies for not following this up! Detailed infor-mation is also available on the confer-ence website: www.stvmgermany.com.
Ixodid ticks of the world
Dr. G.V. Kolonin has published the book “Fauna of Ixodid Ticks of the World” and allows free access to its contents. It has been placed on internet at the site http://www.kolonin.org/ . The book will be reviewed in the next issue of the newsletter.
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Local woman from Myra, southern Turkey, taking her goat out for a walk. Photograph: Anton van Woerkom.
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ADDRESSES OF THE EDITORS
Dr. Gervásio H. Bechara (GB)Professor of Animal Pathology Faculty of Agricultural and Veterinary Sciences São Paulo State University Via de Acesso Professor Paulo Castellane 14884-900 Jaboticabal-SP, Brazil Tel.: +55 16 3209 2662 Fax: +55 16 3202 4275 e-mail: [email protected](Editor for Ticks)
Dr. E.J. (Liz) Glass (LG)Group Leader, The Roslin InstituteRoyal (Dick) School of Veterinary StudiesUniversity of EdinburghRoslin Biocentre, MidlothianEH25 9PS, United KingdomTel.: +44 131 527 4200 Fax: +44 131 440 0434E-mail: [email protected] (Editor for Theileriosis (caused by T. annulata)
Dr. Louise Jackson (LJ)(Some papers may be summarised by others, e.g. Drs A.J. (Bert) de Vos (BdV) or Jess Morgan (JATM), not figuring in the editors’ list)Department of Primary Industries and Fisheries Locked Mail Bag 4Moorooka, Qld., AustraliaTel.: +61 7 33629428Fax: +61 7 33629440 E-mail: [email protected](Editor and co-ordinator for Babesiosis (caused by Babesia bigemina and B. bovis)
Prof. Frans Jongejan (FJ)Utrecht Centre for Tick-borne DiseasesFaculty of Veterinary MedicineP.O.Box 80.165, 3508 TD Utrecht
The NetherlandsTel.: +31 30 253 2568Fax: +31 30 253 2333E-mail: [email protected] and: Dept. of Veterinary ScienceUniversity of Pretoria, Private Bag X04Onderstepoort 0110, South Africa(Editor for Ehrlichiosis)
Dr. Wayne K. Jorgensen (WJ)Queensland Department of Primary IndustriesAnimal Research InstituteLocked Mail Bag no. 4Moorooka Qld. 4105, AustraliaTel.: +61 7 3362 9455Fax: +61 7 3362 9429E-mail: [email protected](Editor for Babesiosis (caused by Babesia bigemina and B.bovis)
Dr. Frank Katzer (FK)Moredun Research InstitutePentland Science ParkBush Loan, PenicuikMidlothian EH26 OPZScotland, United KingdomTel.: +44 (0) 131 44 55 111Fax: +44 (0) 131 44 56 235E-mail: [email protected] (Editor for Theileriosis (caused by other species than T. annulata))
Prof. Katherine M. Kocan (KK)Department of Veterinary Pathobiology 250 McElroy Hall, College of Vet. MedicineOklahoma State UniversityStillwater, OK. 74078-2007, USATel.: +1 405 744 7271Fax: +1 405 744 5275E-mail: [email protected] (Editor for Anaplasmosis)
The ICTTD-3 Coordination Action Project in clud ing this newsletter is financed by the INCO programme of the European Commission, Brussels, Belgium through Coordination Action Project No. 510561. The Newsletter is published by the Faculty of Veterinary Medicine of Utrecht University, The Netherlands
ISSN: 1385-3422
Printing: Atalanta, Houten, The NetherlandsE-mail: [email protected]
For administrative matters please contact:Ms. Jona Bovy, Public Relations, ICTTD.Utrecht Centre for Tick-borne DiseasesFaculty of Veterinary MedicineUtrecht UniversityVisiting address:Yalelaan 13584 CL UtrechtThe Netherlands.Tel.: +31-30-253 4882; Fax: +31-30-253 2333E-mail: [email protected]
Prof. Frans Jongejan coordinates the ICTTD-3 Coordination Action Project.Tel.: +31-30-253 2568Fax: +31-30-253 2333E-mail: [email protected]
The ICTTD Newsletter is also available elec-tronically at: http://www.icttd.nl
Inquiries: webmaster: Hans Nieuwenhuijs,E-mail: [email protected]
Mr. John Molloy (JM)E-mail:[email protected] (new)(Editor for Babesiosis (caused by Babesia bigemina and B.bovis)
Dr. Vishvanath Nene (VN)Institute for Genome SciencesUniversity of Maryland School of MedicineHSF-II, Room S-44720 Penn StreetBaltimore, MD 21201, USATel.: +1 410 706 3860Fax: +1 410 706 1482E-mail: [email protected](Editor for the section on Genomics)
Drs. Ard Nijhof (AN)Utrecht Centre for Tick-borne DiseasesFaculty of Veterinary MedicineP.O.Box 80.165, 3508 TD UtrechtThe NetherlandsTel.: +31 30 253 4882Fax: +31 30 253 2333E-mail: [email protected] (Editor for Babesiosis (caused by other species than B. bigemina and B. bovis)
Dr. Ulrike Seitzer (US)Veterinär Infektiologie und Immunologie Forschungszentrum Borstel Parkallee 22, 23845 Borstel, Germany Tel.: +49 (0)4537 188 413 Fax.: +49 (0)4537 188 627 E-mail: [email protected](Editor for Theilerioses (caused by other species than T. annulata))
Prof. Gerrit Uilenberg (GU)« A Surgente », route du Port20130 Cargèse (Corsica), FranceTel.: +33 4 9526 4083 (= also fax number) E-mail: [email protected] (Chief editor, and editor for Cowdriosis and Dermatophilosis)
Dr. Alan R. Walker (AW) Royal (Dick) School of Veterinary StudiesSummerhall, Edinburgh, EH19 1QH Scotland, United KingdomTel.: +44 (0) 131 650 7838or: +44 (0) 131 466 0255 Mobile phone: +44 (0)77 538 246 59Fax: +44 (0) 131 651 3903 E-mail: [email protected] (Editor and co-ordinator for Ticks)
Dr. Peter Willadsen (PW)CSIRO Livestock IndustriesLevel 3 Gehrmann LaboratoriesResearch Road, University of QueenslandSt. Lucia, Queensland, Australia 4072Tel.: +61 7 3214 2467Fax: +61 7 3214 2480E-mail: [email protected] [email protected](Editor for Ticks)
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