Spirochetes and Neisseria (Gram negative) Lecture 36
Post on 31-Dec-2015
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• Spirochete • Axial filament• Treponema pallidum• Syphilis• Chancre• Primary lesion• Darkfield microscopy• Secondary Lesion• Tertiary Lesion • Anti-cardiolipin antibodies• Anti-treponemal antibodies
• Borrelia burgdorferi• Lyme disease• Relapsing fever (other borrelia)• Leptospira (leptospirosis)• Neisseria• Thayer Martin agar• Oxidase test• N. gonorrhoeae• Gonorrhea• N. meningitidis• Meningitis
Key WordsKey Words
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SpirochetesSpirochetes
• Gram negativeGram negative• long, thin, helical, motilelong, thin, helical, motile
• axial filaments axial filaments – locomotionlocomotion– between peptidoglycan layer/outer membrane between peptidoglycan layer/outer membrane
* runs parallelruns parallel
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Histology: Histology: Treponema pallidumTreponema pallidum - testis infected rabbit- testis infected rabbit
www.orl.cz/choroby/ustni/jazyk/zanet/1
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Treponema pallidumTreponema pallidum
• transmission transmission – genital/genital genital/genital – in uteroin utero or during birth or during birth
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• Secondary (2-10 weeks later)Secondary (2-10 weeks later)- systemic spread - systemic spread - flu-like symptoms- flu-like symptoms- skin, particularly- skin, particularly- many organisms- many organisms - Highly infectious
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• TertiaryTertiary – several years laterseveral years later– rarerare– skinskin– central nervous system central nervous system – delayed hypersensitivity delayed hypersensitivity – few organismsfew organisms
* control by immune responsecontrol by immune response
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Microbiological diagnosisMicrobiological diagnosis
• not culturablenot culturable• dark field microscopydark field microscopy
– actively motile organisms actively motile organisms – brightly lit against dark backdropbrightly lit against dark backdrop– light shines at an angle light shines at an angle – reflected from thin organismsreflected from thin organisms– enters objective enters objective
• conventional light microsrcopyconventional light microsrcopy– light shines throughlight shines through– NOT visualizedNOT visualized
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Secondary and Tertiary SyphilisSecondary and Tertiary Syphilis- serology- serology
• screening methodscreening method• antibodies to cardiolipin antibodies to cardiolipin
• specific diagnosisspecific diagnosis• antibodies to treponemal antigenantibodies to treponemal antigen
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• no vaccine no vaccine
• antibiotics (e.g. penicillin) antibiotics (e.g. penicillin) – effectiveeffective
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Other treponemal diseasesOther treponemal diseases
• bejel, yaws and pintabejel, yaws and pinta– extremely rare in US extremely rare in US
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Lyme disease - symptomsLyme disease - symptoms• bacteremia bacteremia
– acuteacute
• arthritisarthritis• cardiaccardiac• neurologicneurologic
– chronic chronic * weeks, months laterweeks, months later
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TherapyTherapy
• early antibiotic therapyearly antibiotic therapy– curable curable * penicillin penicillin * tetracyclinetetracycline
• late antibiotic administrationlate antibiotic administration– ineffectiveineffective
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DiagnosisDiagnosis• serum antibodies to serum antibodies to B. burgdorferiB. burgdorferi.
• laboratory strainslaboratory strains– grow extremely slowly grow extremely slowly – tissue culture media tissue culture media – not bacteriological medianot bacteriological media
• patient body fluids/tissue samplepatient body fluids/tissue sample– almost never growthalmost never growth
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• acuteacute– responds to antibioticresponds to antibiotic–antibodies not detectableantibodies not detectable
• late diagnosislate diagnosis– not curablenot curable– antibodies detectableantibodies detectable
A physicians dilemmaA physicians dilemma
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Lyme DiseaseLyme Disease - -etiologyetiology
• reactive arthritis similar to reactive arthritis similar to – Reiter's syndromeReiter's syndrome– rheumatic feverrheumatic fever
• resembles rheumatoid arthritisresembles rheumatoid arthritis
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Relapsing feverRelapsing fever
• <100/ per year in US <100/ per year in US • transmissiontransmission
–tick-tick-B. hermsiiB. hermsii* rodent, primary hostrodent, primary host
– lice-lice-B. recurrentisB. recurrentis * human, primary hosthuman, primary host
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““Relapsing” fever Relapsing” fever • immune response develops immune response develops
– disease relapsesdisease relapses
• new antigens expressed new antigens expressed – no immunity no immunity – disease reappearsdisease reappears
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DiagnosisDiagnosis
• no culture no culture
• no serological testno serological test
• detected - blood smeardetected - blood smear
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• <100 cases per year in US<100 cases per year in US
• symptomssymptoms–flu-like flu-like –severe systemic diseasesevere systemic disease
* kidneykidney* brain brain * eyeeye
LeptospirosisLeptospirosis
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• infected urine infected urine – rodentsrodents– farm animalsfarm animals
• water water
• through broken skin.through broken skin.
TransmissionTransmission
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Laboratory DiagnosisLaboratory Diagnosis
• serologyserology
• most readily culturable of spirochetes most readily culturable of spirochetes – culture still extremely difficult culture still extremely difficult
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• Gram negative Gram negative • diplococci (pairs of cocci)diplococci (pairs of cocci)• oxidase positiveoxidase positive
• cultureculture• Thayer Martin. Thayer Martin.
– selective selective – chocolate agarchocolate agar
* heated blood (brown)heated blood (brown)
NeisseriaNeisseria
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• found only in manfound only in man• gonorrheagonorrhea• second most common venereal diseasesecond most common venereal disease
N. gonorrhoeae N. gonorrhoeae the “Gonococcus"the “Gonococcus"
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SmearSmear
• polymorphonuclear cellpolymorphonuclear cell
• Gram negative cocciGram negative cocci – many in cellsmany in cells
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• gonoccocal arthritisgonoccocal arthritis– “ “septic” arthritisseptic” arthritis
• dermatitis dermatitis
Dissemination -gonococciDissemination -gonococci
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• β lactamase-resistant cephalosporinlactamase-resistant cephalosporin– e.g. ceftriaxonee.g. ceftriaxone
• resistant strains resistant strains – common common – produce produce β lactamases lactamases– destroy penicillindestroy penicillin
Antibiotic therapyAntibiotic therapy
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• adhesion to genital epitheliumadhesion to genital epithelium– outer membrane outer membrane – pilipili
*Antigenicity Antigenicity highly variable among strainshighly variable among strains
• no vaccine no vaccine
• IgA proteaseIgA protease– also also N. meningitidisN. meningitidis
PathogensisPathogensis
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• Tissue injury Tissue injury – lipopolysaccharide lipopolysaccharide – peptidoglycan peptidoglycan
N. gonorrhoeaeN. gonorrhoeae
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• resides in man only resides in man only
• usually sporadic cases usually sporadic cases – mostly young childrenmostly young children
• outbreaks outbreaks – adults adults – crowded conditions crowded conditions
*e.g. army barracks, dormse.g. army barracks, dorms
N. meningitidisN. meningitidis
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upper respiratory tractupper respiratory tract infection infection – adhesion pili adhesion pili
bloodstreambloodstream
brainbrain
NeisseriaNeisseria meningitidismeningitidis
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• second most common meningitis second most common meningitis – pneumococcus, most common pneumococcus, most common
• fatal if untreated fatal if untreated
• responds well to antibiotic therapyresponds well to antibiotic therapy– penicillin penicillin
Meningococcal meninigitisMeningococcal meninigitis
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Laboratory DiagnosisLaboratory Diagnosis
• spinal fluid spinal fluid – Gram negative diplococci Gram negative diplococci
within polymorphonuclear cellswithin polymorphonuclear cells– meningococcal antigens meningococcal antigens
• CultureCulture– Thayer Martin agar Thayer Martin agar
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