Isolation and identification of Taylorella asinigenitalis from a mare in Oklahoma, USA

Abstract

Contagious equine metritis (CEM) is a highly contagious venereal disease of horses whose etiologic agent has been identified as Taylorella equigenitalis. The bacterium is a catalase and oxidase positive pleomorphic Gram-negative coccobacillus which grows best in a humidified environment of reduced oxygen (95% air containing 5% CO2) on Eugon chocolate agar. During routine screening of an Oklahoma equine breeding population slated for export, a T. equigenitalis-like organism was isolated. Based on results from requisite conditions for cultivation, biochemical tests, 16S rDNA and intergenic spacer region (ISR) sequence analyses, the isolated organism was identified as Taylorella asinigenitalis. As required by federal regulations, this identification was confirmed at the National Veterinary Services Laboratories (NVSL) in Ames, IA. Pulsed-field gel electrophoresis (PFGE) analysis revealed that the newly identified strain has a distinct genomic fingerprint from the two previously characterized T. asinigenitalis isolates from the United States and represents the second strain to be recovered from a horse in the US.