Spirochetes And Neisseria Faculty: Dr. Alvin Fox

SPIROCHETES AND NEISSERIA Faculty: Dr. Alvin Fox

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Key Words • • • • • • • • • •

Spirochete Axial filament Treponema pallidum Syphilis Chancre Primary lesion Darkfield microscopy Secondary Lesion Tertiary Lesion Anti-cardiolipin antibodies

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Borrelia burgdorferi Lyme disease Relapsing fever (other borrelia) Leptospira (leptospirosis) Neisseria Thayer Martin agar Oxidase test N. gonorrhoeae Gonorrhea N. meningitidis Meningitis 2

SPIROCHETES Treponema, Borrelia and Leptospira

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Spirochetes • Gram negative • long, thin, helical, motile

• axial filaments – locomotion – between peptidoglycan layer/outer membrane * runs parallel

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Histology: Treponema pallidum - testis infected rabbit

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Treponema pallidum • transmission – genital/genital – in utero or during birth

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Syphilis • chronic • slowly progressive

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• primary lesion - chancre – 10 to 60 days – area of ulceration/inflammation – many organisms

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• Secondary (2-10 weeks later) – systemic spread – flu-like symptoms – skin, particularly – many organisms

mouth muosa

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• Tertiary

– several years later – rare – skin, – central nervous system – delayed hypersensitivity – few organisms * control by immune response

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Microbiological diagnosis • not culturable • dark field microscopy – actively motile organisms – brightly lit against dark backdrop – light shines at an angle – reflected from thin organisms – enters objective • conventional light microsrcopy – light shines through – NOT visualized

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• fluorescence microscopy – antibody staining

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Secondary and Tertiary Syphilis - serology • screening method • antibodies to cardiolipin • specific diagnosis • antibodies to treponemal antigen

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Autoimminty • cardiolipin – self antigen

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• no vaccine • antibiotics (e.g. penicillin) – effective

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Other treponemal diseases •

bejel, yaws and pinta – extremely rare in US

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Borrelia burgdorferi and Lyme disease

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Ixodes scapularis, tick vector for Lyme disease. 18 Also known as Ixodes dammini. CDC

Lyme Disease erythematous rash 19

 A tick bite leads to transmission of B. burgdorferi

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Lyme disease - symptoms • bacteremia – acute • • •

arthritis cardiac neurologic – chronic * weeks, months later

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Therapy • early antibiotic therapy – * *

curable penicillin tetracycline

• late antibiotic administration – ineffective 22

Diagnosis • serum antibodies to B. burgdorferi. burgdorferi • laboratory strains – grow extremely slowly – tissue culture media – not bacteriological media • patient body fluids/tissue sample – almost never growth 23

A physicians dilemma • acute – responds to antibiotic –antibodies not detectable • late diagnosis – not curable – antibodies detectable

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Lyme Disease -etiology • reactive arthritis similar to – Reiter's syndrome – rheumatic fever • resembles rheumatoid arthritis.

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Relapsing fever • <100/ per year in US • transmission –tick-B. hermsii * rodent, primary host – lice-B. recurrentis * human, primary host

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“Relapsing” fever • immune response develops – disease relapses • new antigens expressed – no immunity – disease reappears

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Diagnosis • • •

no culture no serological test detected - blood smear

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Leptospirosis

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Leptospirosis • <100 cases per year in US • symptoms –flu-like –severe systemic disease * kidney * brain * eye 30

Transmission • infected urine – rodents – farm animals

• water • through broken skin.

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Laboratory Diagnosis • serology • most readily culturable of spirochetes – culture still extremely difficult

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NEISSERIA

Neisseria gonorrhoeae 33

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Neisseria • • •

Gram negative diplococci (pairs of cocci) oxidase positive

• culture • Thayer Martin. – selective – chocolate agar * heated blood (brown) 35

N. gonorrhoeae the “Gonococcus" • found only in man • gonorrhea • second most common venereal disease

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Smear • polymorphonuclear cell • Gram negative cocci – many in cells

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Dissemination -gonococci • gonoccocal arthritis – “septic” arthritis • dermatitis

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Antibiotic therapy • β lactamase-resistant cephalosporin – e.g. ceftriaxone • resistant strains – common – produce β lactamases – destroy penicillin 40

Pathogensis • adhesion to genital epithelium – outer membrane – pili *Antigenicity highly variable among strains • no vaccine • IgA protease – also N. meningitidis 41

N. gonorrhoeae • Tissue injury – lipopolysaccharide – peptidoglycan

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N. meningitidis (the “Meningococcus")

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N. meningitidis • resides in man only • usually sporadic cases – mostly young children • outbreaks – adults – crowded conditions *e.g. army barracks, dorms 44

Neisseria meningitidis upper respiratory tract infection – adhesion pili

bloodstream

brain 45

Meningococcal meninigitis • second most common meningitis – pneumococcus, most common • fatal if untreated • responds well to antibiotic therapy – penicillin

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Laboratory Diagnosis • spinal fluid – Gram negative diplococci within polymorphonuclear cells – meningococcal antigens • Culture – Thayer Martin agar 47

Capsule • capsule – inhibit phagocytosis • anti-capsular antibodies – stop infection •antigenic variation – sero-groups • vaccine –multiple sero-groups

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