High Prevalence of Non-ST131 CTX-M-15-Producing Escherichia coli in Healthy Cattle in Lebanon.

Extended-Spectrum Beta-Lactamases (ESBL)-producing Escherichia coli have disseminated in both humans and animals worldwide. However, the ESBL epidemiology in these two reservoirs differs markedly, with CTX-M-15 frequently found in humans and CTX-M-1 preferentially found in animals. Our goal was to estimate the prevalence of fecal carriage of ESBL producers in cattle from 31 farms in Lebanon and to characterize the responsible enzymes. This prevalence was high (26/31, 84% of ESBL-positive farms), with a majority of isolates producing CTX-M-15 (27/40, 67.5%). Strikingly, this distribution is reminiscent of the human ESBL epidemiology, even though none of the bovine isolates belonged to the ST131 human clone. This is the first report of ESBL-producing E. coli in animals in Lebanon. Our data rather suggest the spread of CTX-M-15 plasmids in different E. coli backgrounds. Nonetheless, some CTX-M-15-producing E. coli clones found here have already been reported from animal, human, or environmental sources.