Journal of Veterinary Diagnostic Investigation 2014, Vol. 26(3) 442–447 © 2014 The Author(s) Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1040638714523773 jvdi.sagepub.com Case Report Blastomyces dermatitidis is a fungal pathogen belonging to the taxonomic order, Onygenales. The Onygenales order is defined by the following morphologic characteristics: The sexual teleomorph stage forms rudimentary asci surrounded by a network of hyphae, and the asexual anamorph stage forms either unicellular aleuriconidia or chains of arthroco- nidia. 5 For B. dermatitidis, the corresponding sexual teleo- morph stage is Ajellomyces dermatitidis. 4,5,17 Additionally, the anamorph stage of B. dermatitidis is thermally dimor- phic, existing as a mold form at cooler temperatures (25– 30°C) and converting to a yeast form at warmer temperatures (approximately 37°C). 4,5,17 The mold phase of B. dermatiti- dis is a soil saprophyte, preferentially found in warm, moist acidic soils with high organic content. 5 Endemic regions bor- der the Mississippi, Ohio, and St. Lawrence River valleys and the Great Lakes, and also include parts of Africa and Central and South America. 4,5,8 The usual route of human or veterinary infection is inhalation of conidia, although cutane- ous or oral inoculation has been reported. 4,5,8 In human beings, the estimated incubation period is 4–6 weeks. 5 The more frequently reported susceptible species include human beings, dogs, cats, and horses 1,8 ; however, blastomycosis had been reported in other mammalian species, including a free- ranging black bear. 11 Clinical infection can manifest as local- ized pulmonary or cutaneous disease or can spread to establish disseminated infection. Lung, skin, bone, and the genitourinary tract are the most frequent sites involved. In disseminated cases, lesions can occur in any tissue including lymph node, eyes, central nervous system, liver, kidney, spleen, heart, endocrine organs, and the gastrointestinal tract. 4,5,8 Previous genetic characterization of B. dermatitidis using microsatellite markers revealed that it is a genetically diverse pathogen 21 with the 2 principally divergent genetic groups being associated with different clinical phenotypes. 22 In human patients, group 1 was more frequently associated with respiratory-only infections, while group 2 was more fre- quently associated with disseminated infection. 22 Examina- tion of veterinary isolates revealed that the majority of cases identified were disseminated infections caused by group 2 isolates 1 ; however, statistical analysis of associations between microsatellite group and clinical phenotype was hampered by the small number of group 1 cases. Within the past year (2013), multilocus sequence analysis has led to the proposal of 2 separate phylogenetic species. 6 The present report describes a case of disseminated B. dermatitidis, 523773VDI XX X 10.1177/1040638714523773Group 2 blastomycosis in an alpacaImai et al. research-article 2014 From the Departments of Pathobiological Sciences (Imai) and Medical Sciences (McGreevey), School of Veterinary Medicine, University of Wisconsin, Madison, WI; and Marshfield Clinic Research Foundation, Marshfield, WI (Anderson, Meece). 1 Corresponding Author: Jennifer K. Meece, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449. [email protected] Disseminated Blastomyces dermatitidis, genetic group 2, infection in an alpaca (Vicugna pacos) Denise M. Imai, Nikole McGreevey, Jennifer L. Anderson, Jennifer K. Meece 1 Abstract. A 7-year-old, female Huacaya alpaca presented with a 3-week history of left-sided head tilt and mild ataxia. Despite aggressive supportive therapy with empirical antibiotic, anti-inflammatory, thiamine, and anthelminthic therapy, neurologic signs progressed to a right-sided head tilt, positional nystagmus, and episodes of severe ataxia and obtundation. On necropsy, discrete expansile to poorly delineated infiltrative masses with tan, creamy to grumous exudate were observed in the right petrous temporal bone, right middle and inner ear, right cerebellum and medulla as well as in lung, kidney, liver, spleen, lymph nodes, and the gastrointestinal tract. Impression cytology and histology revealed a myriad of intralesional yeast, 10–25 μm in diameter, with double-contoured walls, granular protoplasm, and broad-based budding. Culture characteristics, including conidial morphology and temperature-dependent yeast phase transformation, were consistent with Blastomyces sp. Positive Blastomyces antigenuria was identified on a postmortem sample of urine. Microsatellite typing and sequencing of the internal transcribed spacer region 2 identified the infecting strain as a genetic group 2 isolate of Blastomyces dermatitidis. The present report of camelid blastomycosis adds intracranial blastomycosis to the differential list for camelid neurologic disease in endemic regions. Key words: Alpacas; Blastomyces dermatitidis; camelids; meningoencephalitis; systemic mycosis.
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