A new strain of Taylorella asinigenitalis shows differing pathogenicity in mares and Jenny donkeys.

BACKGROUND: Three horse mares inadvertently inseminated with semen from a Tayorella asinigenitalis-positive Jack donkey developed severe, purulent endometritis whereas two Jenny donkeys mated naturally to the same Jack donkey did not develop clinical signs of infection. OBJECTIVES: To isolate and identify the causative agent. STUDY DESIGN: Case report. METHODS: Endometrial swabs from the infected mares were cultured on selective and non-selective media under aerobic and microaerophilic conditions. Isolates were subjected to Gram staining, oxidase and catalase tests, the Monotayl Latex Agglutination test and PCR to test for both T. equigenitalis and T. asinigenitalis. In vitro antimicrobial susceptibility testing was performed and the bacterial isolate was genotyped using MLST. RESULTS: A new sequence type of T. asinigenitalis was confirmed. MAIN LIMITATIONS: A limited numbers of mares and donkeys are described. CONCLUSIONS: This strain of T. asinigenitalis causes a severe venereal infection in mares but not in Jenny donkeys.