Chlamydia Flashcards
Chlamydia is a what size? is is facultative or obligate intracellular?
it is SMALL OBLIGATE intracellular (must use drugs that penetrate cell membrane)
What is unique about the replication of chlamydia?
it starts with tiny, infectious, rugged, elementary bodies which “unpack” into reticulate bodies after infection
what do reticulate bodies do?
they form intracellular inclusions that are visible on microscopy; within the inclusions they multiply by binary fission, forming new reticulate bodies and later new elementary bodies
what is the advantage of having both reticulate bodies and elementary bodies?
EB are tiny and tough so they can jump from host cell to host cell, but they are too small to reproduce and RB are large and complex so they can reproduce but they are too delicate to survive outside the cell
What are chlamydia’s virulence factors?
Type 3 secretion system “injectosome” involved in entering host cell and establishing inclusion body
- genes: CopB, CopB2, CopN, Tarp, Pkn5
what types of chlamydia can cause pneumonia?
C. pneumoniae, C. psittaci, and C. trachomatis can all cause pneumonia
what type of chlamydia is a bird-borne, rare, airborne zoonosis?
C. psittaci
Why does urogenital chlamydia infection remain so prevalent now that it can be cured by a relatively cheap antibiotic?
asymptomatic infections form a reservoir + lack of condom use + treated patients can be reinfected by their partner if they don’t both get treated simultaneously
Chlamydia trachomatis can cause a variety of different illnesses, what determines the type of illness?
the serovars!
C. trachomatis Serovars A, B, Ba, C –>
blinding trachoma
spread by secretions, fomites
endemic to Africa, sth Asia
C. trachomatis Serovars L1-L3–>
lymphogranuloma venereum
small ulcer proceeds to painfully swollen lymph nodes near genitals
sexually transmitted
endemic to Sth/ Central America
C. trachomatis Serovars D-K–>
genital “chlamydia”
most common std in US
often asymptomatic
sexually transmitted and transmitted to newborns at birth
How do you diagnose blinding trachoma?
eyelashes turn inward, hx of travel to endemic area
How do you diagnose lymphogranuloma venereum?
buboes, hx of sex while traveling to endemic areas
When would you use diagnostic tests other than the physical exam if you suspect chlamydia?
tissue culture for C. trachomatis in rape victims; serology or MIF to differentiate pneumonias
