Stage is set for breakthrough in food safety

Most Canadians have heard of and are familiar with the danger posed by bacteria such as E. coli, salmonella and listeria — but few of us are aware of something called Campylobacter.

We should be — the bacteria, Campylobacter jejuni, is responsible for as many as 400,000 cases of food poisoning in Canada every year, and the leading cause of bacterial gastroenteritis in Canada.

We may not know its name, but a great many Canadians are familiar with the symptoms of Campylobacter infection — severe abdominal pain, fever, vomiting and diarrhea. While it is rarely life-threatening, as Public Health Agency of Canada researcher Dr. Eduardo Taboada points out, the cost of several hundred thousand people missing a week of work every year makes Campylobacter a significant drain on Canada's economy and productivity.

Common but almost untraceable

"Although the existing methods are slow and in need of improvement, we do have ways to track the source of outbreaks of infections like E. coli and salmonella," says Dr. Taboada. "We can ask the infected person where or what they have eaten recently, and quickly compare a sample of the bacteria that's infected the person with samples taken from the likely sources until we find a genetic match."

In the case of Campylobacter, though it is incredibly common — Campylobacter is shed by virtually every type of livestock, from chickens to sheep — there is no effective way to identify specific strains of the bacteria, making it almost impossible to track the source of an outbreak.

Thanks to some ground-breaking work by Dr. Taboada and his colleagues, that is changing.

New genomics capacity key to progress

Through research made possible by funding from the Government of Canada's Genomics Research and Development Initiative (GRDI), Dr. Taboada and his team have developed an approach to genetic fingerprinting Campylobacter in a matter of hours rather than days, using tools that have been standard equipment in microbiology labs for many years.

"Basically, we've taken a 'bar code' approach to make the process a lot faster and a lot cheaper," says Dr. Taboada. "We've identified a set of genes in the bacteria that acts like a highly specific fingerprint for a particular strain. With this approach, a lab has to look at only a very small part of the Campylobacter genome to see whether it matches the fingerprint of the strain suspected as the source of the infection."

Enhancing food safety

While the results of the work led by Dr. Taboada are not yet in widespread use, it is generating a lot of interest in public health circles across Canada. The British Columbia Centre for Disease Control, for example, is testing the new method in the field, and the Canadian Food Inspection Agency (CFIA) is using it in a major study of Campylobacter in Canada's poultry industry.

"Studies have shown that as much as 70 percent of the raw chicken sold in Canadian grocery stores is contaminated with Campylobacter — that's why it's so important to handle raw chicken properly and cook it thoroughly — but we don't know at what point in the production process the contamination happened," says Dr. Taboada. "Using our method, the CFIA will be able to pinpoint where a specific strain came in, how it moved from place-to-place, and from there, look for ways to reduce its transmission."

Among other benefits, Dr. Taboada says that the new method will ultimately contribute to enhancing the health of Canadians by allowing the agencies tasked with safeguarding the safety of the food supply to quickly and accurately identify the source of a Campylobacter infection.

Establishing Canadian leadership

At Agriculture and Agri-Food Canada (AAFC), food safety researcher Dr. Doug Inglis says the method of characterizing Campylobacter jejuni developed by Dr. Taboada, "puts Canada beyond what others in the world are doing."

"This method allows us to achieve real breakthroughs in reducing the impact of this bacterium on Canadians" says Dr. Inglis. "For example, as part of our research at AAFC, we plan to genotype as many as 20,000 C. jejuni isolates. From there, we will identify which ones pose a danger to humans and which ones are harmless. The genotyping method developed by Dr. Taboada and his team allows us to identify major sources of harmful strains, and how they are transmitted to Canadians, information that's critical to mitigating disease caused by this very important bacterium."

By the same token, Dr. Taboada says that, without the GRDI, his research would have been impossible. "GRDI made it possible for us to conduct meaningful genomic research — to do the kind of fundamental research that led to the results we've been able to achieve," says Dr. Taboada. "GRDI has also promoted collaboration, allowing us to work with people like Dr. Inglis and with the CFIA in building toward real, practical applications that will protect the health and safety of Canadians."

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