The zoonotic chlamydiae with reservoirs in mammals are Chlamydophila abortus, Chlamydophila felis, and possibly Chlamydophila pneumoniae. These organisms are members of the family Chlamydiaceae, an unusual group of obligate intracellular bacteria. The members of this family are considered to be Gram negative, due to their relationships with other Gram negative bacteria, but are difficult to stain with the Gram stain. They have metabolic and structural differences from most bacteria, including a dependence on adenosine triphosphate (ATP) and guanosine triphosphate (GTP) from the host. They cycle through two forms: a metabolically inert, infective elementary body and a metabolically active reticulate body found only inside cells.
Until recently, the Chlamydiaceae contained only a few species: Chlamydia psittaci, Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia pecorum. However, this family has been reorganized, based on analyses of ribosomal RNA. A new genus, Chlamydophila, was established, some species were renamed, and some strains of C. psittaci and C. trachomatis were assigned to new species. Both Chlamydia spp. and Chlamydophila spp. cause the disease chlamydiosis.
Iowa State University
Iowa State University Center for Food Security and Public Health, "Zoonotic Chlamydiae from Mammals" (2005). Center for Food Security and Public Health Technical Factsheets. 35.