Characteristic and antimicrobial resistance in Escherichia coli from retail meats purchased in the Czech Republic

The aim of this study was to characterize and compare Escherichia coli found in retail meats (pork, poultry, beef, venison), focusing on the detection of resistant genes that could be spread through the food chain and also for the presence of selected virulence genes. The resistance to antimicrobial agents was determined by disk diffusion method and E-test. Polymerase chain reaction was used for the detection of selected genes encoding for virulence factors (eaeA, hly, stx1, stx2) and genes encoding resistance to tetracycline, β-lactams and quinolones. Compared to beef isolates, the isolates from poultry and pork displayed higher resistant rates and also possessed more resistance genes. All together, 25.9% of the isolates were positive for the presence of the gene blaTEM, and the presence of any tet gene was detected in 23.1% of the isolates. The production of extended-spectrum β-lactamases was confirmed in one isolate from poultry as well as the presence of a plasmid-mediated gene qnrA attributed to the quinolone and fluoroquinolone resistance. Based on these results, it can be surmised that poultry is the most risk-associated meat source in terms of antibiotic resistance. The stx2e gene was detected in one isolate from pork samples, but this subtype is commonly associated with edema disease in pigs and is seldom found in humans.