Treponema Pallidum Flashcards
(26 cards)
Structural Characteristics of T.Pallidum
Spiral
Darkfield or immunofluorescence
Outer Membrane: NO LPS
3 Axial fibrils aka internal flagellum in periplasm
What are the characteristiscs of T.Pallidum in culture?
Long generation time (30hrs)
Sensitive to drying and heat
Microaerophilic (survives 3-5% O2)
Outer membrane protein antigens not well characterized for pathogenicity
How is Syphilis transmitted?
Intimate sexual contact with infective primary or secondary lesion
Placental transfer- > congenital infection -> neonatal disease
How long after acquiring infection will there be no sexual spread?
> 4 years
Where is syphilic most common in?
Drug use
Truck routes
Core groups
Gay men
Describe the pathogenesis of Syphilis
Pass through intact mucosa/injured skin -> multiply locally -> dissemination to lymph nodes and organs -> no sx until critical level reached (primary lesion at 10-90 days after inoculation)
Which stages of syphilis are self-limiting?
Primary and Secondary
Followed by latency
What is the pathologic lesion in syphilis?
Obliterative Endarteritis
What is the characteristic of primary syphilis?
Ulcerative lesion at site of inoculation with regional adenopathy
Painless papule - chancre Darkfield positive Firm local adenopathy No systemic manifestations Self limiting
What are the characteristics of secondary syphilis?
Systemic flu-like illness 2-10 weeks after primary lesion heals
Papulosquamous rash: entire body
Moist areas-> papules coalesce-> condylomata lata
Other sites: hepatitis, aseptic meningitis, periostitis, nephritis
Fever and generalized lymphadenopathy
Heals spontaneously
May recur over 4 years
What is the result of untreated syphilis?
1/3 will be resolved
2/3 will form latent syphilis or develop into late syphilis
What is involved in tertiary/late syphilis?
Neurosyphilis
CV syphilis: proximal aortic aneurysm, ascending aortic aneurysm
Late benign Gummatous Syphilis: in bone and cartilage, etc
What are characteristics of latent syphilis?
Positive Treponemal Serology Test
No lcinical sx/manifestations
What are the 4 types of Neurosyphilis?
Asymptomatic: CSF infected w/ no signs or sx
Meningovascular: Chronic meningitis -> affects arteries and cranial nerves
Paresis: Cortical degeneration -> mental changes
Tabes Dorsalis: Demyelination of posterior columns and dorsal roots -> ataxia, loss of pain and temp
What is the presentation of congenital syphilis?
Infection in utero
Normal at birth -> multisystem disease later
How can congenital syphilis be prevented?
Prevent with screening of all pregnant women for syphilis
Treat during preganncyc if positive
What are the microscopic diagnosis methods for syphilis?
Darkfield : primary and secondary lesions
Direct Fluorescent Ab test
PCR
Can you culture for syphilis?
No- Cannot cultivate IN VITRO
How is syphilis diagnosed usually?
Screen with RPR -> if positive, confirm with specific treponemal test -> FTA -> positive => syphilis likely
If FTA is negative , RPR is probably false positive
What is RPR?
Rapid Plasma Reagin- Nontreponemal test of patient serum with Ab
What is FTA?
Fluorescent Treponemal Ab-Absorption Test
Pt serum overlayed on dead T.pallidum reagent -> wash -> counterstain with fluorescent anti IgG -> psoitive
Qualitative test
How is Syphilis treated?
Benzathine Pen G - treatment of choice
Single dose injection for primary and secondary syphilis
IV penicillin for 2 weeks or more for tertiary syphilis
What is J-H Reaction?
Reaction after penicillin treatment for syphilis due to toxic products being released from killed spirochetes
What is an alternative treatment for syphilis?
Tetracycline
