VANCOUVER—While traditional methods for detecting salmonella are labour-intensive and time-consuming, a new and ever-so-small device can now identify the potentially deadly bacteria within minutes.
Following several outbreaks across Canada this year, University of British Columbia researchers say the “user-friendly” tool is overdue and there’s a “real potential” to benefit both consumers, and companies.
“Salmonella is a major threat to food safety and is one of the most common pathogens, which is why it is so easily transferred to humans,” said Dian Zou, a visiting international research student who worked on the project. “It is known to cause over 80 million cases of infections and 155,000 deaths each year worldwide.”
In fact, the most recent Health Canada and Canadian Food Inspection Agency investigation — which is currently in progress — has an estimated 84 infections linked to raw poultry, including frozen breaded chicken products. That number was updated on July 30.
That’s why the team wanted to create an affordable, practical and speedy single-detection tool for everyday use. By using fabric (both cotton and silk) as a test base instead of paper, the gadget is the first of its kind, according to researchers.
And it can fit in the palm of the hand: the tool is compacted into three-and-a-half centimetres, Zou said.
The method is simple: add a splash of water into a bag of fresh veggies and a buffer — made up of a phosphate saline solution to match pH levels. Place a few drops of water on the test strip and wait roughly 10 minutes. If the device shows two red lines then salmonella is present, she explained.
Zou, who was visiting from China, worked on the tool as part of the Mitacs Globalink program, which brings hundreds of people to Canada each year to tackle research challenges.
The project has been in the works for more than a year, according to Azadeh Nilghaz, lead researcher and food science post doctoral fellow with roughly a decade of experience in the field.
“This can be used in our kitchens. It is made of natural fibres, it’s plastic-free, low-cost and disposable if incinerated,” Nilghaz said in an interview. “Since it’s for food products, we are trying to keep the price as low as possible to encourage consumers and companies to use it.”
But the hand-held contraption won’t be testing salmonella in cucumbers or tomatoes alone. The aim is to test for other pathogens, such as E. coli, in the future, she noted.
The cotton is “perfect,” she added, because the fabric is cellulose-based, which is necessary for the bacteria test.
And the team is still working on extending the shelf life, Nilghaz said, which involves testing different chemicals and antibodies to bring down the price. Currently, the tool can be used for up to three months. But the goal is to stretch that ability up to two years.
Nilghaz, who works out of the UBC Lu Food Safety & Health Engineering Lab, expects the project to wrap in six months.
“Say you just bought a cucumber and you want to test it,” she explained. “You won’t buy a rapid test for $10. It has to make sense.”
Melanie Green is a Vancouver-based reporter covering food culture and policy.