Prevalence of extended-spectrum beta-lactamase producing enterobacteriaceae in companion animal clinical specimens

Abstract

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in companion animals pose a growing concern for veterinary therapeutics and public health. This research determined the prevalence, species distribution, and genotypic profiles of ESBL producers from clinical specimens of companion animals in Busan, South Korea, between March 2022 and February 2024. Of 648 non-duplicate specimens screened on cefotaxime-supplemented MacConkey agar, 142 (21.9%) yielded ESBL producers. Dogs accounted for 61.3% of positive isolates, followed by cats (28.9%). Escherichia coli was predominant (68.3%), followed by Klebsiella pneumoniae (18.3%). blaCTX-M was the most common gene family (82.4%), with CTX-M-15 and CTX-M-14 predominating. Multi-gene isolates had significantly higher cefotaxime MICs (geometric mean 78.4 vs. 12.3 µg/mL; p<0.001). These findings confirm a substantial ESBL burden in companion animals in South Korea.