what type of cell is chlamydia?
Chlamydial Genitourinary Infections - Background. 1  Chlamydial infection can cause disease in many organ systems, including the genitourinary tract. Chlamydiae are small gram-negative obligate intracellular microorganisms that preferentially infect squamocolumnar epithelial cells. They include the genera Chlamydia (of which the type species is Chlamydia trachomatis) and Chlamydophila (eg, Chlamydophila pneumoniae and Chlamydophila psittaci). C trachomatis can be differentiated into 18 serovars (serologically variant strains) on the basis of monoclonal antibodyâbased typing assays.