Cambridge University researchers have found antibiotic-resistant E. coli on 24 percent of chicken samples tested from the seven largest supermarkets in the U.K. That contamination level is four times higher than results from a similar study done last year.
The researchers tested 189 U.K.-sourced pork and poultry samples from the grocery chains ASDA, Aldi, Co-op, Morrisons, Sainsbury’s, Tesco and Waitrose.
The type of E. coli highly resistant to cephalosporin antibiotics, known as ESBL E. coli, was found on poultry samples from all of those stores. However, no pork samples tested positive for ESBL E. coli.
For the chicken, scientists tested diced breast meat, whole roasting chickens, and packets of thighs and drumsticks, and detected E. coli in 22 of 92 samples.
A total of 51 percent of the E. coli from chicken and pork samples were resistant to the antibiotic trimethoprim, which is used to treat lower urinary tract infections.
“The levels of resistant E. coli that we have found are worrying. Every time someone falls ill, instead of just getting a food poisoning bug, they might also be getting a bug that is antibiotic resistant,” Cambridge professor Mark Holmes told The Guardian newspaper.
“I am concerned that insufficient resources are being put into the surveillance of antibiotic resistance in farm animals and retail meat. These results highlight the need for improvements in antibiotic stewardship in veterinary medicine.”
In a recently released report, the British Poultry Council noted that producers had reduced antibiotic use by 44 percent since 2012. The U.K. industry group called this fact “amazing” given that poultry meat production went up by 5 percent during the same period.
“Resistance is complex and we have seen evidence of it persisting even after stopping the use of antibiotics. Like any life, bacteria are subject to natural selection so we need to continue challenging the resistant bacteria in an environment hostile to its continuation. How best to do this is just one of the incredibly difficult questions we and the scientific community are trying to answer,” the council stated on its website.
Save Our Antibiotics, the U.K.-based advocacy group which commissioned the study, said the findings should be a wake-up call for supermarkets and the government.
“They show that many consumers are being exposed to high levels of antibiotic resistance daily at meal time,” said Cóilín Nunan, a scientific advisor to the group. “Scientific evidence is accumulating that the overuse of antibiotics on farms is an important contributor to antibiotic resistance in E. coli infections.”
According to data from Public Health England, E. coli kills more than 5,500 people each year in England alone, which is more than twice as many as MRSA (Methicillin-resistant Staphylococcus aureus) and Clostridium difficile combined.
E. coli bacteria can be killed by thoroughly cooking meat and poultry. To be safe, USDA’s Food Safety and Inspection Service recommends cooking pork to an internal minimum temperature of 145 degrees F and chicken to an internal minimum temperature of 160 degrees F.
