Spirochaetes are a family of bacteria characterized by their spiral shape and flexible motility. There are three main families: Treponema, which causes syphilis; Borrelia, which causes relapsing fever and Lyme disease; and Leptospira, which causes leptospirosis. Treponema pallidum, the causative agent of syphilis, has a regular spiral shape and can be seen under dark field microscopy after silver staining. Syphilis progresses through primary, secondary, and tertiary stages if left untreated. It is acquired through sexual contact and enters through skin abrasions.

1. SPIROCHAETES
Dr. Ashish Jawarkar M.D.

2. Spirochaetes
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Spiro = flexible, motile
Three families
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Treponema – syphilis
Borrelia – relapsing fever, Lyme disease
Leptospira - leptospirosis

3. Treponema pallidum
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regular spirals
Cannot be seen by ordinary microscopy
in wet films, cannot be stain by ordinary
stains
Can be seen under dark ground
microscopy
Can be stained by silver impregnation

6. Syphilis
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Acquired by sexual contact
Enter through abrasions
Multiply at site of lesion
Primary
Secondary
Tertiary

7. Primary syphilis
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Hard chancre – at site of entry
Usually on genitalia
Covered by thick pus – rich in
treponemes
Regional lymphnodes swollen and
rubbery
Heals in 2 weeks – leaving a scar –
without treatment

8. chancre

9. Secondary syphilis
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1-3 months after chancre
Rashes in oro pharynx, condylomata at
mucocutaneous junctions
Spirochetes are abundant in lesions

10. Condyloma acuminata

11. Latent syphilis
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Following secondary syphilis, there is a
latent period
During this time, diagnosis is possible
only by serological tests

12. Tertiary syphilis
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Months to years after primary lesion
Represents delayed hypersensitivity
Organisms are not present in lesions
Include aneurysms, gummata,
neurological manifestations

13. aneurysm

14. gumma

15. Dementia paralytica

16. Lab diagnosis
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Sample – serum from chancre, gumma
Collected by scraping base/margin
Highly infectious – handle with care
Wet films examined under dark
background
DFA-TP – direct fluoroscent antibody
test for Treponema pallidum

18. Serological tests
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Non specific
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VDRL (veneral disease research laboratory)
RPR (rapid plasma reagin)
TPI
Specific
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FTA-ABS
TPHA
EIA

19. VDRL
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We use cardiolipin antigen obtained
from bovine heart
Look for antibodies in serum of patient
Mix serum with antigen – look for
agglutination under microscope

20. RPR – rapid plasma reagin
test
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Antigen is attached to carbon particles
– can see agglutination with naked eye

22. False positive reactions
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Leprosy
Malaria
Relapsing fever
Infectious mononucleosis
Hepatitis
Tropical eosinophlia

23. FTA-ABS
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Fluoroscent treponemal antibody
absorption test
Mix patients serum with artificial
treponemes
The artificial treponemes are immotile
under dark field microscope

24. Treatmemt
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Penicillin G injection single shot is
sufficient in early cases
Doxycycline
Ceftriaxone in neurosyphilis

25. Borrelia
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Transmitted to humans through skin
Bite of lice or ticks
B. recurrentis – relapsing fever
B. burgdorferi – Lyme disease

27. Lyme disease

28. Leptospira
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Lepto – thin
Delicate spirochaetes with large number
of closely wound spirals and
characteristic hooked ends

30. L. Interrogans - leptospirosis

31. Selective media
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EMJH MEDIUM – (Ellinghausen, Mc
Cullough, Johnson, Harris)

32. Leptospirosis

34. Leptospirosis
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Fever
Jaundice
Hepato renal damage (Weil’s disease)

36. Lab diagnosis
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Demonstration of leptospira in urine
Serological tests like
sensitized erythrocyte lysis test
complement fixation
agglutination
indirect immunofluorosence