Scientists who discovered evidence of extremely rare strains of antibiotic-resistant E. coli in chicken sold in some Canberra shops say the threat to human health is low.
Researchers from the Australian National University's Research School of Biology tested more than 90 packages of chicken bought from several Canberra retailers for the presence of the bacteria E. coli.
The ABC this week reported researchers discovered a small number of strains containing E. coli that were resistant to antibiotics not used in Australia's poultry industry.
Professor of microbial population biology and evolution, David Gordon, said almost 200 samples were found to contain E. coli and of those, about two-thirds were discovered to be antibiotic-resistant strains of E. coli.
Just four strains of E. coli were found to be resistant to antibiotics known as fluoroquinolone, which were not used by Australia's poultry industry, he said.
Professor Gordon said the E. coli strains researchers found were rare in the samples.
He said it was unlikely the strains of fluoroquinolone-resistent E. coli were in the chicken before slaughtering, and the "most logical, although not necessarily true, explanation for their presence in poultry is post-processing contamination".
"It probably occurred post-processing because we know those strains are out there in the environment," he said. "We know we find them in dogs and therefore it wouldn't surprise me if we found them in humans and from humans, they can get back to the poultry meat.
"I would argue that given the relatively high frequency of fluoroquinolone-resistant E. coli from humans and other animals, the risk these rare strains in chicken meat pose to humans is low."
Professor Gordon said E. coli bacteria could be easily killed by cooking chicken properly.
"E. coli – relative to many other kinds of bacteria – are real wimps when it comes to high temperature and the E. coli starts dying rapidly at 50 degrees, so if you've cooked the chicken properly, there's no risk. You've killed it."
An ACT Health spokeswoman said although the directorate had not seen the study, the presence of resistant bacteria in chicken meat highlighted the importance of good food handling and preparation when eating chicken, including thorough cooking and cleaning of food-preparation surfaces.
"This is important to prevent bacterial food-borne illness regardless of whether bacteria are resistant to an antibiotic," she said.
"Although this research was conducted at ANU and the chicken meat was therefore sourced from Canberra supermarkets, the ACT does not have a large commercial chicken-meat industry," she said.
"Any use of antibiotics in commercial chickens is likely to be a wider issue for primary production in Australia generally."
An Australian Pesticides and Veterinary Medicines Authority spokeswoman said the was responsible for the assessment and registration of veterinary medicines, including antibiotics, in Australia.
She said fluoroquinolones have never been registered for use in food-producing animals in Australia.
"State and territory governments are responsible for controlling the use of pesticides and veterinary medicines beyond the point of retail sale," she said.
A Department of Agriculture spokeswoman said states, territory and local government food-regulatory agencies were responsible for ensuring all food, imported and domestically produced, available for sale within their jurisdiction met Australia New Zealand Food Standards Code requirements.
She said the department worked with these agencies to respond and manage food-safety incidents that may involve imported food.
"The Department of Agriculture’s main role in residues is to monitor imported food and some agricultural products destined for export," she said.
She said all imported food must meet Australia’s strict biosecurity and food-standard requirements. She said the department routinely inspected and tested imported foods for compliance with the Food Standards Code.
Professor Gordon said the research was part of an ongoing study. He said E. coli resistant to flouoroquinolones from poultry meat had been reported in WA.