Mouse Anti-Chlamydia Monoclonal antibody for IF. Chlamydia is a genus of bacteria that are obligate intracellular parasites. Chlamydia infections are the most common bacterial sexually transmitted infections in humans and are the leading cause of infectious blindness worldwide. The three Chlamydia species include Chlamydia trachomatis (a human pathogen), Chlamydia suis (affects only swine), and Chlamydia muridarum (affects only mice and hamsters). Prior to 1999, the Chlamydia genus also included the species that are presently in the genus Chlamydophila: Two clinically relevant species, Chlamydophila pneumoniae and Chlamydophila psittaci were moved to the Chlamydophila genus.