E. coli was isolated from the samples, cultured, and analyzed. The E. coli isolates are screened against a panel of antimicrobials to determine their susceptibility. The AMR phenotype, which is the pattern of resistance to antimicrobials, was determined through polymerase chain reaction (PCR) and whole genome sequencing (WGS) analyses. AMR phenotype is characteristic of the β-lactamase enzymes produced by the E. coli isolate, of which there are 3 main AMR phenotypes: AmpC, ESBL, or carbapenemase-producers. ESBL and AmpC enzymes confer resistance to cephalosporins, while carbapenemase enzymes confer resistance to the “last resort” carbapenem antibiotics.  

Overall, the results showed the prevalence of AMR among E. coli in retail beef and pork samples to be low, with less than 1 percent and less than 4 percent of beef and pork samples respectively possessing an ESBL- or AmpC-expressing E. coli. None of the meat samples prior to enrichment had AmpC-/ESBL-phenotype E. coli counts above the EU detection levels, indicating low numbers of the bacteria on meat samples.

In comparison to surveillance conducted in 2015, 2017, and 2019, the prevalence of AMR among E. coli has remained low, with little variation. Carbapenem-resistant E. coli strains have not been detected over the past seven years of surveillance, and only one beef sample (of non-EU origin in 2017) tested positive for colistin-resistant E. coli. The results show the prevalence of resistant E. coli in the UK to be lower than the average prevalence for all 28 EU member states combined.