gram-negative-type cell wall but no peptidoglycan,smaller than most bacteria.

C. trachomatis strains are the most common cause of bacterial sexually transmitted disease. Sequelae in women include pelvic inflammatory disease, ectopic pregnancy and sterility. A subset of C. trachomatis strains cause trachoma, a leading cause of preventable blindness in the developing world.
C. pneumoniae is estimated to be responsible for about 10% of community-acquired pneumonia and 5% of bronchitis and sinusitis cases in adults. Furthermore, C. pneumoniae is of intense interest because chronic infection with this pathogen might contribute to cardiovascular disease.

Bacteria; Chlamydiae; Chlamydiia; Chlamydiales; Chlamydiaceae; Chlamydia