Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Food-Producing Animals in Tamaulipas, Mexico

Abstract

Extended-spectrum β-lactamase (ESBL)-producing <i>E. coli</i> has become an important global problem for the public health sector. This study aims to investigate the <i>E. coli</i> antimicrobial resistance profile among living food-producing animals in Tamaulipas, Mexico. A total of 200 fecal samples were collected from bovines, pigs, chickens and sheep. A total of 5.0% of the strains were phenotypically confirmed as ESBL producers. A high percentage of phenotypic antimicrobial resistance was observed against gentamicin (93.3%), tetracycline (86.6%) and streptomycin (83.3%). The gentamicin-resistant strains showed MDR, distributed among 27 resistance patterns to different antimicrobials. The antimicrobial resistance gene <i>tet</i>(A) was detected in 73.3% of isolates, <i>aad</i>A1 in 60.0% and <i>sul</i>2 in 43.3% of strains. The <i>bla</i>_CTX-M gene was found in 23.3% of strains. The virulence gene <i>hlyA</i> was detected in 43.3% of isolates; <i>stx</i>1 and <i>stx</i>2 were not detected in any strain. The phylotyping indicated that the isolates belonged to groups A (33.3%), B1 (16.6%), B2 (40.0%) and D (10.0%). These results show that food-producing animals might be a reservoir of ESBL-producing bacteria and may play a role in their spread.