Irish study to look at how bacteria, Yersinia enterocolitica, enters the food chain

Monitoring of pig carcasses and pig meat in slaughterhouses, butchers' premises and retail outlets will be undertaken in Ireland over the next two years in an attempt to determine how a human disease causing bacteria, Yersinia enterocolitica, enters the food chain, scientists announced today (Tuesday 4 September 2007) at the Society for General Microbiology's 161st Meeting at the University of Edinburgh, UK, which runs from 3-6 September 2007.

The survey will look at 1,800 pig tissue samples from 3 slaughterhouses and 200 pork meat samples from 50 retailers.

So far, of 516 samples studied, 12 (2%) have already been found with non-disease causing Yersinia enterocolitica, and 15 samples (3%) have been found to contain the bacteria with disease causing genes.

Some of the contaminated samples were also shown to contain antibiotic resistant strains of the bacteria, representing an emerging pathogen which is a potential public health risk.

“Yersinia enterocolitica is widespread in nature and found in animals and water supplies. These bacteria can cause serious gastroenteritis in humans, and sometimes the symptoms can mimic appendicitis, leading to unnecessary surgery. The bacteria colonise the tonsils and the neck muscles of pigs and as a result may enter the food chain”, says Dr Brenda Murphy of the Veterinary Food Safety Laboratory, Cork County Council and Centre for Food Safety, University College Dublin.

Public health officials do not yet know quite how significant (or not) the problem is. Once the key environmental reservoirs of the pathogen are known, the main entry points into the food chain will be identified. Consumers and the food industry will benefit from improved biosecurity measures based on our scientific findings. This will lead in turn to better monitoring and reduction in the risk of dissemination of the pathogen.

“Once we have identified the full extent of the problem in pigs our future work may include screening other food animals such as cattle to work out where else this organism might be,” says Dr Murphy. “We also hope that our antimicrobial resistance data will facilitate clinicians to improve antibiotic treatments in cases of human and animal infections when required”.