Antibiotic resistant bugs have been found in cheese despite a three-year-old Europe-wide ban on the agricultural use of the veterinary drug thought to be responsible.
The study, by Giorgio Giraffa at the Istituto Sperimentale Lattiero Caseario in Lodi, Italy, revealed a quarter of bacterial strains isolated from the cheeses sampled contained vancomycin-resistant enterococci (VRE).
While the bugs are mostly harmless to humans, research published in the journal Food Microbiology underlines the ability of resistant strains to persist in the environment.
Use of vancomycin to boost the health of cattle was banned across Europe to prevent resistant strains of bacteria spreading. The fear is that VRE could pass their antibiotic resistance on to other bacteria, including human pathogens. Some vancomycin-resistant "superbugs" have already claimed victims in the United Kingdom.
The discovery of high frequencies of VRE in several different cheeses, mostly traditional ones made from raw milk, suggests the resistant bugs are likely to persist for a long time in the environment and that some cattle farmers may still be illicitly using the banned antibiotics.