SPIROCHETES DR .JEYAKUMAR NELSON UNIT OF MICROBIOLOGY MBBS -BATCH 17

Lecture 21 & 22 : Spirochetes The objectives of this lecture are to discuss the classification of Spirochetes. describe the general characteristics of Treponema, Leptospira and Borrelia. discuss the epidemiology, pathogenicity, laboratory diagnosis, prophylaxis and principles of treatment of diseases caused by Spirochetes.

Learning Outcomes list the medically important genus among At the end of this lecture, students should be able to: list the medically important genus among spirochetes. discuss the morphology and virulence of Treponema pallidum, Borrelia burgdorferi and Leptospira interrogans. distinguish between screening tests and confirmatory tests done for “syphilis”.

Spirochete from Greek for “coiled hair”

Classification of Spirochetes

Spirochaetales Associated Human Diseases Genus Species Disease Treponema pallidum ssp. pallidum pallidum ssp. endemicum pallidum ssp. pertenue carateum Syphilis Bejel Yaws Pinta Borrelia burgdorferi recurrentis Many species Lyme disease (borreliosis) Epidemic relapsing fever Endemic relapsing fever Leptospira interrogans Leptospirosis (Weil’s Disease)

Note Trepos= turn, nema= thread, pallidum=pale staining Dr.P.K.Rajesh.M.D

OVERVIEW

Morphology and virulence

Penile Chancre Labial Chancre Facial Chancre Mucous Membrane

Saber shins Hutchinson’s teeth Saddle nose

LABORTORY DIAGNOSIS DETETION

Darkfield Microscopy of Treponema pallidum

Screening tests and confirmatory tests for syphilis Primary Secondary Confirmatory tests Dark ground Microscopy Serological tests Screening tests VDRL/RPR Wasserman’s CFT FTA-ABS TPHA TP-EIA Distinguish between screening tests and confirmatory tests for syphilis SCREENING Initiated by Doctor CONFIRMATORY Initiated by patient Apparently healthy Sick or screening test positive Less accurate More accurate Less expensive More expensive Applies to all Based on 1 criteria Not basis for treatment Applies to individual Signs,symptoms,lab Basis for treatment

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Morphology and virulence

Comparison of Diagnostic Tests for Leptospirosis

DIRECT EXAMINATION Microscopy -Fontana staining and DFM Culture media-EMJH PCR –Molecular diagnosis Microscopy -Fontana staining and DFM

Lyme disease Borrelia burgdorferi Dr.P.K.Rajesh.M.D

Epidemiology of Borrelia Infections Pediculus humanus Borrelia recurrentis Ornithodoros spp. Borrelia spp. Ixodes spp. Borrelia burgdorferi

Morphology and virulence

-overview -overview

Pathogenesis of Lyme Borreliosis Lyme disease characterized by three stages: Initially a unique skin lesion (erythema chronicum migrans (ECM)) with general malaise ECM not seen in all infected hosts ECM often described as bulls eye rash Lesions periodically reoccur Subsequent stage seen in 5-15% of patients with neurological or cardiac involvement Third stage involves migrating episodes of non-destructive, but painful arthritis Acute illness treated with phenoxymethylpenicillin or tetracycline

Epidemiology of Lyme diseases

Diagnosis of Lyme Borreliosis

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