The Food Standards Agency (FSA) has published two reports on antimicrobial resistance (AMR) and bacteria in salmon and meat.
One survey generated new data on the presence of Listeria monocytogenes, E. coli, and the levels of AMR in raw, chilled, prepacked farmed salmon fillets on sale in the UK.
A total of 307 salmon fillets were collected from major supermarkets between January and December 2024. Samples came from 12 approved establishments with Scotland and Norway as the main countries of origin.
Listeria monocytogenes was found in five salmon fillets at levels of less than 20 colony forming units per gram (cfu/g) and was not resistant to common antibiotics. Other Listeria species were detected in 31 samples.
Possible human infections
Four Listeria monocytogenes isolates were from the same retailer but sampled in several regions at different times with various batch numbers and different processing establishment codes.
Two isolates showed genetic similarities with strains linked to listeriosis cases: one closely matched an isolate from a human case from August 2023, and another was similar to strains from four infections in 2020. Listeria infections are usually treatable with penicillin or ampicillin, but often result in serious illnesses and sometimes death.
Additional data on AMR resistance came from reviewing WGS results from 15 Listeria monocytogenes strains previously detected in raw salmon samples by UK Health Security Agency laboratories between 2015 and 2024. All 20 isolates carried genes that show potential resistance to benzalkonium chloride, a quaternary ammonium compound widely used as a disinfectant in the food industry.
E. coli was detected in 108 samples, albeit at low levels. Of 102 isolates examined, four were resistant to one type of antibiotic, ampicillin.
No extended spectrum beta-lactamase (ESBL)/Amp C-producing E. coli, colistin resistant or carbapenemase-producing E. coli were found.
No salmon samples had E. coli or Listeria monocytogenes that were resistant to clinically important antibiotics. This means the likelihood of consumers acquiring Listeria and AMR from UK retail raw salmon fillets is low.
Second study
Another study tested 300 chicken and 300 turkey fresh retail meat samples for ESBL, AmpC Beta-Lactamase and Carbapenemase enzyme producing E. coli.
Samples were collected from retailers in Northern Ireland from January to December 2024.
The overall prevalence of ESBL and AmpC producing E. coli was 12 percent with 73 of 600 samples positive. The prevalence was 9 percent from chicken and 15 percent from turkey.
From the 300 chicken samples, 13 were positive for ESBL E. coli and 14 for AmpC E. coli. Of 300 turkey samples, 35 were positive for ESBL E. coli and nine for AmpC E. coli.
No isolates were resistant to last line antibiotics, including colistin and carbapenems. There was resistance to ampicillin and cefotaxime.
“The risk of acquiring AMR related infections through the handling and consumption of retail contaminated meats is very low with proper food handling and cooking practices,” said the FSA.
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