Extended-Spectrum β-lactamase-Producing in Retail Pork and Market Environments: Genetic Diversity and Antimicrobial Resistance in Thailand.

The increasing prevalence of extended-spectrum β-lactamase (ESBL)-producing () highlights the growing issue of multidrug resistance within the food processing chain. This study aimed to determine the prevalence, antimicrobial resistance profiles, molecular genetic structures, and genetic diversity of ESBL-producing isolated from pork, cutting boards, and knives. A total of 90 samples were collected from 10 local markets in Southern Thailand. ESBL-producing were identified in 9 samples (10%), with knife samples showing the highest contamination rate (5/90, 5.55%). The ESBL-producing isolates exhibited high-level resistance to ampicillin (100%), ceftriaxone (88.89%), and cefpodoxime (88.89%), followed by tetracycline (77.78%). Multidrug resistance was detected in 88.89% (8/9) of ESBL-producing isolates and 28.26% (13/46) of all isolates. All presumptive ESBL-producing isolates carried ESBL resistance genes (9/9, 100%), with being the most prevalent (6/9, 66.67%). Additionally, the gene was frequently detected in ESBL-producing (6/9, 66.67%) and in all isolates (16/46, 34.78%). Overall, O157:H7 was identified in 5 isolates (10.87%). The genetic relatedness analysis revealed that five ESBL-producing isolates were closely related to ATCC 23502. Our findings confirm a high prevalence of ESBL-producing carrying resistance genes in knife samples, underscoring the importance of proper sanitary handling practices to minimize microbial contamination in pork retail shops.