The UK Food Standards Agency (FSA) has found the prevalence of Escherichia coli with antimicrobial resistance (AMR) to be low in retail beef and pork. The findings are the result of surveillance of AMR in E. coli on retail meats, which has been conducted annually since 2015.
The surveillance study involved the sampling of 300 beef and pork products that were on sale in UK retail stores between October and December 2021. Samples were taken from 80 retail stores across England, Scotland, Wales, and Northern Ireland, and the retail stores were strategically selected to represent a majority of the UK population. Typically, the annual testing and sampling of retail meats for AMR surveillance occurs in higher volumes over the course of a full year, but Brexit caused a delayed start in sampling and testing activities for 2021.
The samples were tested based on current EU protocols, wherein the culture of E. coli is placed on selective agar media containing certain antimicrobial drugs; growth of E. coli on selective media indicates resistance to the selective agent. The E. coli isolates were screened against a panel of antimicrobials to determine their susceptibility. At the request of FSA, E. coli isolates were also tested for their resistance to colistin, which is a crucial antibiotic that is considered a “last resort” drug for the treatment of highly resistant pathogens in humans.
A total of 105 beef and 105 pork samples were tested, none of which yielded any growth of E. coli at the time of initial culture prior to bacterial enrichment. Samples did yield E. coli growth post-enrichment, with one beef sample and four pork samples yielding AMR E. coli. None of the E. coli isolates showed resistance to carbapenem or exhibited colistin-resistant genes. However, two pork samples contained E. coli isolates that tested positive for cephalosporin-resistant genes.
More specifically, the five E. coli isolates derived from the beef and pork samples were evaluated to determine their AMR phenotypes. The single E. coli isolate from beef showed resistance to all four of the cephalosporin antibiotics it was tested against—efepime, cefotaxime, cefoxitin, ceftazidime—and the four pork isolates were resistant to at least two of the cephalosporin antibiotics. All five E. coli isolates were resistant to ampicillin, but did not show any resistance to amikacin, temocillin, or tigecycline. None of the isolates were resistant to any of the carbapenem antimicrobials they were tested against—ertapenem, imipenem, and meropenem—or to colistin.
The report summarizes that less than 1 percent of beef samples and less than 4 percent of pork samples showed resistance to carbapenem or cephalosporin antimicrobials. Additionally, none of the meat samples contained E. coli counts above EU detection levels prior to enrichment. None of the beef or pork samples that have been tested since 2015 have contained E. coli with resistance to colistin, with the exception of a single beef sample in 2017.
Since the regular surveillance of AMR in UK retail meats began in 2015, there has been very little change in the prevalence of AMR E. coli. The prevalence of AMR E. coli in retail beef and pork is lower in the UK than the average prevalence for all 28 EU Member States combined.
