Mechanisms of infertility in genital tract infections due to Chlamydia psittaci transmitted through contaminated semen.

Ten heifers inseminated with semen artificially contaminated with Chlamydia psittaci were not pregnant 40 days later, whereas five of 10 control heifers inseminated with the same semen mixed with control diluent became pregnant. Normal embryos were recovered two and one-half or three days after insemination of another group of animals with semen containing C. psittaci, a finding indicating that fertilization failure was not responsible for the infertility. Uterine biopsy samples taken from two heifers in this group contained scattered Chlamydia-infected cells that were detected by immunofluorescence in the subepithelial tissues of the uterine horns. This finding suggests that the infertility may result from an alteration in the uterine environment caused by multiplication of C. psittaci.