Occurrence of extended-spectrum β-lactamase and AmpC-producing Escherichia coli in retail meat products from the Maritime Provinces, Canada

Abstract

This study was conducted to determine the occurrence of antimicrobial resistance to the extended-spectrum cephalosporins (ESC) in Escherichia coli isolates recovered from retail meat products collected in the Maritime Provinces of Canada using both selective and traditional culture methods, and genotypically using multiplex polymerase chain reactions. ESC-R E. coli was detected in 33/559 (5.9%) samples using the traditional culture compared to 151/557 (27.1%) samples using the selective culture method. The recovery of ESC-R E. coli isolates was more common in poultry compared to beef and pork (P<0.001). Multi-drug resistance, ESBL, and AmpC phenotypes were more common in chicken-derived isolates than other retail meat products (P<0.001). From the 98 isolates selected, 76 (77.6%) isolates were positive for either ESBL and AmpC {beta}-lactamases or both. Among the 76 isolates, blaCMY-2 (78.9%), blaCTXM (46.1%), blaTEM (21.1%), and blaSHV (1.3%) were detected. Among the blaCTXM-producing isolates; blaCTXM-1, blaCTXM-2, and blaCTXM-9 phylogenetic groups were detected. {beta}-lactamase genes were detected more in chicken-derived isolates compared to other meat types (P<0.01). This study demonstrated the occurrence of ESBL and AmpC resistance genes in retail meat products in Maritime Provinces of Canada. Also, selective culture significantly improved the recovery of ESC-R E. coli isolates from retail meat samples.