Bacterial Record Checks: Suspects of the Food Safety System

E. coli -- though we tend to associate it with foodborne illness outbreaks, most forms of the bacteria live naturally in the intestines of healthy humans and animals.

But some kinds of bacteria associated with food, can make people sick and cause a range of illnesses. During a foodborne illness outbreak, public health officials across the country need to know which food products pose a risk to Canadians.

In order to tell if there is a foodborne illness outbreak, the Public Health Agency of Canada (PHAC) relies on its experts and laboratory tests to identify illnesses that are related to one another.

Genomics: A Deluxe Security System for Foodborne Pathogens

In an earlier blog, we looked at how PHAC and its food safety partners including the Canadian Food Inspection Agency, investigate, monitor, and respond to foodborne illness outbreaks. When lab experts identify that many people are becoming ill from the same strains of bacteria —like E. coli, Listeria, or Salmonella— the information is shared with epidemiologists who work to identify the contaminated food. If the contaminated food can be identified, a food recall is initiated.

Previously, scientists at PHAC’s National Microbiology Laboratory (NML) relied on “wet lab” approaches to identify the ‘genetic fingerprint’ of foodborne illness-causing bacteria. The NML’s “wet labs” were traditional labs where scientists used petri dishes and microscopes.

Now, to identify the disease-causing bacteria, NML scientists use genomics - the science of understanding, interpreting and harnessing the genetic code in “dry labs” using advanced computing. Genomics can generate an organism’s entire DNA with incredible precision and accuracy. This is used to examine DNA of the bacteria for common markers to link the bacteria collected from patients with the ones collected from food.

Imagine that the bacterium being studied is actually a crime novel. The old technology provided a sneak peek of the table of contents, while new advanced genomic methods generate every word present in the book for our disease detectives.

The use of genomics and advanced computing technologies provides Canada’s food system a deluxe security structure. NML scientists can now identify high-risk foodborne agents during an outbreak with greater accuracy. These technologies are setting the next gold standard for public health and are being made available to other federal and provincial partners.

The Bacterial Record: Data for the Future

Computer data generated by genomics technologies allow scientists to identify an outbreak and launch a response to it. This data also contributes to genetic storehouses that can be used to identify disease caused by matching bacteria in future.

For instance, during a Salmonella outbreak associated with chicken nuggets in Canada, the NML used genomics to generate a complete genome, characterized the illness-causing strain in the chicken nuggets, and as a result was able to quickly link cases across Canada with the contaminated chicken nuggets.

With the advancement of genomics, Canada has a stronger ability to respond to future foodborne outbreaks and help protect the health of Canadians.