What are the three genera of spirochetes?
-Treponema -Borrelia -Leptospira
What organism causes syphilis?
Why can't we see Treponema pallidum on light microscopy? What kind of microscopy is needed to see them?
-they are too narrow -Need darkfield microscopy or EM
What is the outermost amorphous layer of Treponema pallidum?
What diagnostic tests do we use to detect Treponema pallidum?
Non-treponemal antibody tests: -VDRL (venereal disease research lab of CDC) -RPR (Rapid Plasma Reagin) Treponemal antibody tests: -MHA-TP (MIcrohemagglutination antibody to T. pallidum) -EIA (Enzyme immunoassay)
Where does Treponema pallidum get phosphatidylcholine?
-can't make its own -takes it from mammalian host =cardiolipin
What tests detect cardolipin in Treponema pallidum?
=non-treponemal antibody tests -VDRL test (venereal disease research laboratory) -RPR (rapid plasma reagin test)
What is the epidemiology of Treponema pallidum?
-Natural spread only among humans -Sexual transmission
What disease does Treponema pallidum cause?
What is weird about the flagella of spirochetes?
They are located underneath the outer membrane
What is the first sign of syphilis?
Primary syphilis = lesion called chancre -incubation of 7-21 days before papule appears
Why is primary syphilis harder to detect in women and homosexual men?
-chancre often in vaginal canal or rectum -syphilis usually diagnosed in second stage
What happens to the primary syphilis chancre without treatment?
-Disappears in 3-4 weeks -reflects development of some immunity
What is secondary syphilis?
-organisms have disseminated widely throughout body -Lesions appear all over skin, truck>extremitis and **involves palms of the hands and soles of the feet" -partial immunity prevents these lesions from turning into a chancre
What is seen in the CSF of patients with secondary syphilis?
What kind of patient will develop early neurological symptoms of syphilis?
What is latent syphilis?
-organism is in body, but not causing any signs of disease -Occurs in absence of treatment of secondary syphilis
What are the three things that can happen once syphilis becomes latent?
1/3 eradicate disease 1/3 remain with latent disease; keep reactive RPR 1/3 develop tertiary syphilis
What are the three types of tertiary syphilis?
-Benign -Cardiovascular -Neurologic
What is benign tertiary syphilis?
-Gummas: large, immunologically mediated, granulomatous lesions of skin, liver testis, hard palate ***RARE
What is cardiovascular tertiary syphilis?
-Aneurysm of ascending aorta due to invasion of vasa vasorum *RARE
What is neurologic tertiary syphilis?
Wide variety of sx's -tabes dorsalis -strokes -dementia -paresis *CSF is usually abnormal
What is the most reliable diagnosis of primary syphilis?
-detection of treponemes in the canchre by darkfield exam *difficult in secondary lesions
What is the treatment for syphilis?
-Long acting penicillin b/c of slow dividing time
What is the Jarisch-Herxheimer reaction?
-Treatment of syphilis with penicillin is followed in 4 hours by a fever that may be high and the worsening of lesions
What organism causes Lyme disease?
What is the natural reservoir and vector of Borrelia burgdorferi?
Reservoir: White-footed mouse Vector: hard tick (Ixodes)
What are the tree stages of Lyme disease?
1) Localized infection 2) disseminated infection 3) Persistent destructive arthritis & cardiac disease
What is stage 1 of Lyme disease?
-localized infection -nonspecific generalized symptoms -Erythema migrans
What is stage 2 of lyme disease?
-disseminated infection (multiple smaller erythema migrans) -arthritis (large joints), carditis (heart block), neurologic disease (Bell's Palsy) "outbreak" of acute arthritis