Treponema pallidum, borrelia and leptospira interrogans Flashcards
Give the four subspecies of Treponema pallidum
Treponema pallidum
Treponema pertenue
Treponema endemicum
Treponema carateum
What disease does Treponema pallidum cause?
Syphilis (worldwide)
What disease does Treponema pertenue cause?
Yaws
What disease does Treponema endemicum cause?
Endemic syphilis (Middle East and Central and South Africa)
What disease does Treponema carateum cause?
Pinta
What is the shape of Treponema spp?
Helically coiled, corkscrew shaped cells with 8-12 regular spirals
Are Treponema encapsulated?
No
Is Treponema motile?
Yes
Can Treponema form spores?
No
What can Treponema form instead of spores in the body
Cysts
How are Treponema different from other motile bacteria?
Endoflagella
Is Treponema gram positive or neegative?
It is gram negative
Is Treponema pallidum aerobic or anaerobic
Strict anaerobe
What staining method can be used to reveal Treponema from smears?
Silver impregnation methods
How can live Treponema be visualised?
Dark field microscopy
How difficult is it to culture Treponema pallidum?
It is fastidious, requiring very narrow pH and temperature ranges. It has not been successfully cultured in vitro
Describe the resistance of Treponema pallidum
It can not survive a long time in the environment. It is rapidly inactivated by mild heat, cold,
desiccation, and most disinfectants.
It is inactivated by contact with oxygen, distilled water, soap
T.pallidum is sensitive to arsenicals, mercurials, bismuth, common antiseptic agents and
antibiotics (penicillines).
How is Treponema pallidum transmitted?
Through sexual contact (venereal disease);
Through placenta (congenital syphilis);
Rarely with direct contact and with infected blood during transfusion
How long is the incubation period for syphilis?
Incubation period is about a month (10 - 90 days)
Give 4 stages in the clinical manifestation of infection with Treponema Pallidum
Primary syphilis
Secondary syphilis
Latent syphilis
Tertiary syphilis
How does primary syphilis begin?
The organisms penetrate mucous membranes or enter through the very tiny cuts on the skin.
Treponema multiplies in the site of entry causing formation of the primary specific lesion, named
“hard chancre”.
Describe the chancre of primary syphilis
Chancre is painless, circumscribed, indurated, superficially ulcerated lesion
What is the next stage of primary syphilis after formation of a chancre?
Treponema disseminates away from the site of initial entry to regional lymph nodes and
provokes their specific inflammation (syphilitic buboes).
Describe the changes in regional lymph nodes in primary syphilis
Lymph nodes are swollen, discrete,
indurated, and rubbery.
What is the normal progression of a chancre over time in primary syphilis?
The chancre heals spontaneously (!) in 10-40 days, leaving a thin scar
Roughly how long does primary syphilis last?
3 months
When does secondary syphilis set in?
3 months after primary syphilis
What causes the secondary lesions in syphilis?
The secondary lesions are due to dissemination through
the blood and wide-spread multiplication of the spirochetes.
How may secondary syphilis present?
It may appear with: ROSEOLAR RASHES PAPULAR RASHES MUCOUS PATCHES (broad, flat, erosive lesion of secondary syphilis that occurs on moist skin or mucous membranes and is often marked by a yellowish discharge) CONDYLOMATA (anogenital warts).
In which stage of syphilis are patients most infective?
The secondary stage as the spirochetes are present abundantly in the lesions
What is the natural progression of secondary syphilis?
Lasts 2-3 years
Lesions heal
spontaneously (!) but during first 4-5 years there may be relapses of rashes
How is latent syphilis diagnosed?
Serological tests
When does tertiary syphilis present?
Years to decades after secondary syphilis
How does tertiary syphilis present?
After several years tertiary syphilis
appears with cardiovascular lesions (aneurysms), chronic gummata and neurological
manifestation (tabes dorsalis or dementia)
What are gummas?
Highly destructive lesions (necrotizing granulomas ) that usually occur in skin and
bones but may also occur in other tissues. Gumma includes few treponemes
How well does the immune system deal with Treponema pallidum?
Immunity is weak, non-sterile, and cell-mediated. Antibodies which are formed during infection
are not protective
What is the significance of the antibodies produced during infection by Treponema pallidum?
Diagnostic significance
Can a person be reinfected with Treponema pallidum?
Yes (superinfection)