Spirochetes and Neisseria (Gram negative) Lecture 36

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SpirochetesSpirochetes and NeisseriaNeisseria (Gram negative)

Lecture 36

Faculty: Dr. Alvin Fox

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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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SPIROCHETESSPIROCHETESTreponema, Borrelia Treponema, Borrelia andand

LeptospiraLeptospira

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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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SyphilisSyphilis

• chronicchronic

• slowly progressiveslowly progressive

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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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• fluorescence microscopy– antibody staining

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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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AutoimmintyAutoimminty

• cardiolipin cardiolipin – self antigenself 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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Borrelia burgdorferiBorrelia burgdorferi and Lyme and Lyme diseasedisease

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

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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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LeptospirosisLeptospirosis

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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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Neisseria gonorrhoeae

NEISSERIANEISSERIA

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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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N. meningitidisN. meningitidis (the “Meningococcus")

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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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• capsulecapsule– inhibit phagocytosisinhibit phagocytosis

• anti-capsular antibodiesanti-capsular antibodies– stop infectionstop infection

•antigenic variationantigenic variation– sero-groupssero-groups

• vaccine vaccine –multiple sero-groups multiple sero-groups

CapsuleCapsule