Salmonella solution

McMaster University researchers have developed a quick and inexpensive test for Salmonella contamination in chicken and other foods – a test that is easier to use than an at-home COVID test.

The test, described in a new paper in the journal Applied chemistrycan improve food safety, reduce the cost of processing fresh poultry and other foods, and help limit widespread recalls for batches that have been specifically identified as contaminated.

Researchers have shown that the test provides accurate results in one hour or less without the need for accessories or a power source, compared to current monitoring via laboratory culture, which requires at least a full day to produce results.

Once scaled up and commercially available, this new test could be of significant benefit to poultry processors, for whom Salmonella poses one of the most significant contamination risks. This test will also be useful in ensuring the safe processing of other foods that are highly susceptible to Salmonella, such as eggs, dairy products and ground beef.

One primary poultry processor does tens of thousands Salmonella laboratory tests every year. Reducing or even eliminating the need for overnight laboratory cultures represents significant savings and makes it easier to identify contamination early in the process.

“Anyone can use it right where food is prepared, processed, or sold,” said co-author Yingfu Li, a professor of Biochemistry and Chemical Biology who leads McMaster’s Functional Nucleic Acid Research Group. “There is a balance between cost, convenience and necessity. If it’s cheap, reliable, and easy, why not use it?”

Protecting the public from Salmonella is a high priority for food manufacturers, retailers and regulators Salmonella is one of the most common and serious forms of foodborne infection, causing 155,000 deaths globally each year.

What made the test work were the new synthetic nucleic acid molecules, which were developed at McMaster. For testing, molecules are sandwiched between microscopic particles such as gold.

The test platform coats the inside of the pipette tip and starts working when a liquid sample of the food being tested is taken in the tube.

If Salmonella bacteria is present, they cut the particles, allowing the molecules to escape.

When the solution was dropped onto the test strip paper, there was Salmonella shows a visible red color, thanks to a new biosensor shape, also created by the McMaster team. The greater the concentration of Salmonellathe brighter the color.

“Using this test is easier than using the COVID test, which many people are already doing,” said co-author Carlos Filipe, chair of McMaster’s Department of Chemical Engineering. “For this to be as effective and useful as possible, it has to be easy to use.”

The new technology has been developed with support from the non-profit research organization Mitacs, and Toyota Tsusho Canada Inc., an indirect subsidiary of Toyota Tsusho Corporation in Japan, which plans to develop the innovation for commercial use.

This research is part of a broader ongoing effort to establish McMaster and Global Nexus for Pandemics and Biological Threats as a center for the development of real-time sensors, pathogen repellents, and other products that improve food safety.

“This was very important to us in the development of our food testing program,” said co-author Tohid Didar, a professor of Mechanical Engineering and Canadian Research Chair in Nano-biomaterials. “Being able to make a test that is easy to use and produces an easily visible color within an hour is very important.”

Li, Didar and Filipe co-authored the paper with postdoctoral research associate Jiuxing Li, PhD student and Vanier Scholar Shadman Khan, and research associate Jimmy Gu.

Reducing disease and food waste is in line with Toyota Tsusho Canada values, said Grant Town President Toyota Tsusho Canada Inc.

“Our goal is to help bring proven research from the lab to market, which can benefit society,” said Town. “Reducing disease risk while cutting food waste will benefit everyone, and Toyota Tsusho Canada sees this as a great opportunity.”