Extended-spectrum β-lactamase-producing Enterobacteriaceae from ready-to-eat foods: Genetic diversity and antibiotic susceptibility.

Ready-to-eat (RTE) foods are widely marketed in China and are important components of everyday diet. In this study, a total of 2000 RTE food samples were analyzed, 252 (12.60%) of which were positive for Enterobacteriaceae, and 48 were identified as containing extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates. Furthermore, the antimicrobial resistance patterns of these isolates to 14 antimicrobial agents revealed that most isolates were resistant to aminoglycosides and β-lactam antibiotics. The TEM-type gene was prevalent in our isolates (79.17%). The isolates (n = 48) were classified into three clusters based on the ERIC-PCR results. Forty-eight sequence types were found without duplicates, revealing genetic variation and relatedness among isolates. Thus, the results demonstrated the presence of ESBL-producing Enterobacteriaceae in Chinese RTE foods. The results of this study provide insights into the spread of antibiotic-resistant strains and improve understanding of microbial risks.