Review Question - QID 101476

The presentation and laboratory findings described are consistent with Lymphogranuloma venereum (LGV), a sexually transmitted infection (STI) caused by Chlamydia trachomatis. C. trachomatis can only be grown within live cells, such as the chick embryo yolk sac.

C. trachomatis, an obligate intracellular bacteria, cannot produce ATP on its own; it steals ATP from the host cell by using an ATP/ADP translocator and releases ADP as it is consumed. There are several serotypes of C. trachomatis that cause different diseases: A-C cause chronic conjunctivitis; D-K cause urethritis, pelvic inflammatory disease, neonatal pneumonia and conjunctivitis; L1-L3 cause LGV which is the clinical presentation of the male in the question. Serotypes L1-L3 are transmitted sexually and result in painless papules at the site of infection which will heal while the bacteria spread to the regional lymph nodes where they will multiply. The lymph nodes will begin to enlarge and form buboes which may fuse, suppurate, and create multiple sinuses that may lead to proctitis or rectal strictures.

Figure A shows a Giemsa staining demonstrating the inclusion bodies of C. trachomatis.

Incorrect Answers:
Answer 1: Bordet-Gengou agar is used to culture Bordetella pertussis.
Answer 2: Löwenstein-Jensen agar is used to culture Mycobacterium tuberculosis.
Answer 3: Charcoal yeast extract agar with cysteine and iron is used to culture Legionella.
Answer 4: Eaton's agar is used to culture Mycoplasma pneumoniae.