An investigation by the Bureau of Investigative Journalism has revealed meat sold in two British supermarkets has been contaminated with MRSA ‘superbugs’.

MRSA is a multi-drug resistant type of Staphylococcus aureus (also called staph); staph bacteria are widely found on skin, in throats and noses of humans and other animals, but can nevertheless cause blood poisoning and worse if they manage to enter the body. The danger of MRSA lies in how difficult it is to treat, as the bacteria can shrug off most antibiotics.

Pork products from Sainsbury’s and Asda supermarkets were found to be contaminated with with the bugs. Testing on a total of 97 products from the two retailers by the Alliance to Save our Antibiotics revealed three samples were contaminated. Last month the Alliance also found a quarter of chicken meat from UK supermarkets was contaminated with drug-resistant E.Coli.

The Bureau highlighted regulatory loopholes which could allow pigs contaminated with the superbug to enter the country. Though Denmark has taken measures to tackle resistant bugs, and bring down antibiotic use in the country, MRSA is rife in the country’s pig herd, and there is no live screening for the bacteria in live pigs leaving the country for the UK.   

However, British produced pork contaminated with livestock-associated MRSA has also found its way onto supermarket shelves. The Bureau is recommending immediate action and better surveillance measures to prevent the bug from becoming more widespread.

Although health officials state that MRSA should be killed when meat is cooked properly, in the past ten years up to 12,000 people have contracted livestock-associated MRSA in Denmark, which has a population 11 times smaller than Britain.

Responding to the findings, Ross Fitzgerald, Chair of Molecular Bacteriology at The Roslin Institute in Edinburgh said, “The identification of MRSA CC398 in UK supermarket samples has been reported previously and is not surprising considering the high prevalence of MRSA among pig populations in some countries in Europe. However, even in Denmark, food-borne transmission of MRSA to humans is very limited.

“Cooking meat properly and washing hands effectively should prevent any impact on humans. Furthermore, there is no evidence that the presence of MRSA in pork will lead to a pandemic in human populations.” Prof Fitzgerald did say, “Continued and better surveillance of humans and livestock for antibiotic resistant bacteria is required to understand the dynamics of resistance at the interface between humans and livestock.”

Nevertheless, Erik Millstone, a professor of food safety at the University of Sussex, told the Bureau of Investigative Journalism that officials and experts are wrong to downplay the seriousness of these discoveries. Prof Millstone contested the “Usual response” from officials of “‘If people cook food properly then they’re not at risk’.” He said, “Not everyone cooks everything properly, and cooks often handle [meat] before they cook it. We increasingly eat outside of our homes, and from kitchens in cafes and restaurants where it’s impossible for consumers to know how the food is prepared or cooked. The emergence of antibiotic strains of pathogenic bacteria is a huge threat to human health and the health of livestock.”

The Bureau said the Red Tractor certification scheme, which covers more than 90% of British pig producers, requires testing for livestock-associated MRSA, but the certifier wouldn’t share any information on compliance with the requirements.

The Bureau’s full report is available here.