infectious diseases
Chlamydia
Introduction
Three species ofChlamydiacause human disease, including sexually transmitted infections and respiratory infections. Diagnosis depends on species; culture, nucleic acid amplification tests (NAATs), or serologic tests may be done. Treatment is withdoxycyclinefor nonpregnant people and withazithromycinfor pregnant women. Chlamydiae are nonmotile, obligate intracellular bacteria. They contain DNA, RNA, and ribosomes and make their own proteins and nucleic acids. However, they depend on the host cell for 3 of their 4 nucleoside triphosphates and use hostadenosinetriphosphate (ATP) to synthesize chlamydial protein. The genusChlamydianow contains 12 species; 3 of them cause human disease: Chlamydia trachomatis Chlamydia pneumoniae Chlamydia psittaci Chlamydial species can cause persistent infection, which is often subclinical. 