Chlamydia is a common term for infection with any bacterium belonging to the phylum Chlamydiae. This term derives from the name of the bacterial genusChlamydiain the family Chlamydiaceae， order Chlamydiales， class and phylum Chlamydiae. There are two genera in Chlamydiaceae: Chlamydia and Chlamydophila. The genus Chlamydia includes three species: C. trachomatis， C. muridarum， and C. suis.
