Chlamydia trachomatis is a gram-negative, obligate intracellular bacterium that causes the most common sexually transmissible diseases in the world. Serovars L1, L2, L2a and L3 of C. trachomatis are the agents of lymphogranuloma venereum, a disease found in isolated groups of men who have sex with men (MSM) across Western Europe, North America, and Australia.
