Proposal of Chlamydia pecorum sp. nov. for Chlamydia strains derived from ruminants.

Chlamydia pecorum sp. nov. is proposed as the fourth species of the genus Chlamydia on the basis of the results of a genetic analysis of Chlamydia strains that were isolated from cattle and sheep which had various diseases, including sporadic encephalitis, infectious polyarthritis, pneumonia, and diarrhea. The levels of DNA-DNA homology between C. pecorum and strains of C. psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis were less than 10%. Several DNA probes were used to identify C. pecorum. The C. pecorum strains were distinguished from C. psittaci strains by the results of immunological assays, including an immunofluorescence antibody assay performed with monoclonal antibodies and an immunoblot analysis of the immunological specificity of the major outer membrane protein. Species identification was based on results obtained from DNA analyses and serology. The type strain of C. pecorum is strain ATCC VR628.