The Occurrence and Characterization of Extended-Spectrum-Beta-Lactamase-Producing Isolated from Clinical Diagnostic Specimens of Equine Origin.

isolates were recovered from clinical specimens of equine patients admitted to the Texas A&M Veterinary Medical Teaching Hospital over a five-year period. Ceftiofur resistance was used as a marker for potential extended-spectrum beta-lactamase (ESBL)-activity, and of the 48 ceftiofur-resistant isolates, 27.08% ( = 13) were phenotypically ESBL-positive.