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Canadian researchers invent quick test for E. coli in food New device tests for E. coli contamination



Researchers at a Canadian university have developed a test that can detect a particularly severe strain of E. coli bacteria much more quickly than existing methods.

The team from Western University in London, Ont. says its testing kit can show whether a food has been contaminated with E. coli O157 in a matter of hours, rather than the days or weeks it currently takes for test results to come back.

Food samples to be tested are incubated for a few hours. A sample is then placed on a pad. After 15 minutes, the pad displays one red line to show it worked properly – and a second if the sample contains E. coli O157.

“It’s very much like a pregnancy test,” Rieder told CTV’s Your Morning on Thursday.

The O157 strain, which is commonly found in ground meat, is considered more likely to cause severe illnesses than other forms of E. coli. Approximately 440 cases of E. coli O157 are reported in Canada in an average year.

Rieder and his team at Western say their kit also makes the process of testing for E. coli O157 cheaper than existing technology, which could make smaller-scale producers more amenable to testing their products.

The main benefit to quicker testing, they say, is that results are received long before contaminated products make it to market – reducing the risk to the public and the need for large-scale food recalls.

“You can have an area in the plant where you can test the food directly,” Rieder said.

“It’s quick, it’s simple and it’s not expensive.”

The kit has received approval from Health Canada and was developed with support from the food industry.

“By this time next year, we’re hoping that it’s in routine use in food plants,” Rieder said.

E. coli O157 is the same strain responsible for dozens of recent illnesses in Canada and the U.S. linked to romaine lettuce. The Public Health Agency of Canada has advised people living in Ontario and Quebec not to consume any romaine lettuce until more details about the source of the illnesses is known.

While quicker detection of E. coli O157 contamination could lead to fewer foodborne illnesses, some experts say there are other ways to address all dangerous forms of contamination.

“It’s like finding a needle in a haystack. It’s best not to have needles in that haystack,” Keith Warriner, a food science professor at the University of Guelph, told CTVNews.ca Wednesday via telephone.

Warriner said he would like to see more focus put on decontamination processes at commercial food processing facilities and other efforts to stop E. coli contamination at its source rather than catch it after it has affected foods.

Public health authorities have been playing that sort of catch-up game with the recent reports of contaminated romaine. No recall has been issued, which is the same way the Public Health Agency of Canada and U.S. officials handled a similar outbreak involving romaine last year.

Warriner said the health authorities may have been reluctant to issue a blanket recall on romaine because of the harm it would cause to producers and vendors of products having no connection to the illnesses – even though warning of potential danger caused many people to avoid romaine altogether.
“You wouldn’t expect it from a public health agency, but it seems to be becoming the norm now,” he said.

“You might as well do a blanket recall, because who’s going to serve romaine lettuce now?”