New rapid test for E. coli improves food safety

Dr. Michael Rieder and his team have created a new rapid-test system to detect E. coli 0157 – a food-borne bacteria most commonly found in ground meat.

The test would allow manufacturers to identify contaminated food quickly before it leaves the processing plant and enters the grocery store. The system was developed as a result of collaborations between Dr. Rieder, professor, Schulich School of Medicine & Dentistry, and associate scientist at Robarts Research Institute, and London entrepreneurs, Michael Brock and Craig Combe.

Current conventional testing can take from three to 21 days for definitive results and relies on bacterial culture. By the time the bacteria are identified, the food has been shipped to grocery stores and may have already caused illness. With this current system, two weeks of food may need to be recalled to ensure against cross-contamination.

Dr. Rieder's rapid-test system would allow food to be sampled at the end of one day, and the results would be available before the food is shipped the next morning. “This means that one day’s production is lost, not five days production,” he said. “This has the potential to save companies considerable money, and more importantly could save a lot of people from being exposed to food-borne disease.”

On average, 440 cases of E. coli 0157 infection in humans are reported annually to the Public Health Agency of Canada.

The rapid-test relies on targeting proteins identified by Dr. Rieder’s lab that are only present in the organisms that cause people to become ill. By collaborating with Toronto-based company, International Point of Care, the team was able to use flow-through technology to mark the protein with colloidal gold so that it is visible to the naked eye. The process is similar to that used in pregnancy tests – one line for negative, two lines for positive.

Much of the work has been funded through a grant from Mitacs, a federal non-profit that encourages academic and industrial collaboration. Dr. Rieder credits the success of the project to these collaborations with industry, as well as colleagues at Robarts and Schulich Medicine & Dentistry. Sadly, Michael Brock, a key member of this project, died suddenly just as it was entering its final stages.

The rapid-test system has completed testing at Robarts and the Health Canada-certified Agriculture and Food Laboratory at the University of Guelph. The final application has been submitted to Health Canada for approval.