Hunting down bacteria

Hunting down bacteria

May 1, 2002

To hunt the wily E. coli bacteria, microbiologist Mansel Griffiths has to come armed.

In fact, Griffiths knows that to hunt down the sometimes-deadly strains of the persistent bacteria, it takes a potent combination of knowledge and skill-and the right weapons.

But don't go looking through Griffiths' arsenal for traditional items like guns and ammo. That would be too "Wild West" for a job involving complex, nearly invisible bacteria. Instead, the microbiologist prefers to conduct the hunt using the latest state-of-the-art equipment that science has to offer—including a confocal laser-scanning microscope that will be part of his weapons cache at the new Canadian Research Institute for Food Safety at the University of Guelph.

Griffiths believes the new equipment should make all the difference. "This equipment is important for looking at how micro-organisms interact with their environment and with food matrices," he says. "We know that microorganisms are not distributed homogeneously throughout food. For instance, E. coli 0157 H bacteria can actually play hide-and-seek on the leaves of produce, embedding themselves in surfaces on lettuce leaves. To understand this sort of relationship, it's important to use some microscopic tools."

And Griffiths should know. He's one of the leading Canadian researchers studying the behaviour of pathogenic bacteria, which includes E. coli, salmonella, campylobacter, and cyclospora, to name a few.

Although safe food-handling practices can reduce the amount of illness that consumers contract from undercooked meats or cross-contaminated food, it's not a guarantee. Researchers are discovering that food-borne illnesses caused by salmonella, E. coli, and other bacteria like campylobacter and shigella are creeping into the food chain in ways too difficult for consumers to prevent.

Although individual researchers at the food safety institute are effective and highly regarded in international food-safety circles, Griffiths says they've been hampered in their efforts to collaborate on key issues of food safety. The reason? More than 50 university, federal, and provincial government researchers are scattered in laboratories and buildings across the University of Guelph's campus, making it difficult to combine resources and skills. They've also struggled to build an international identity for their institute.

With support from the CFI and the Ontario Innovation Trust, the University of Guelph is establishing its state-of-the-art complex for the institute. The university is renovating a building to house both the institute and a new, highly secure containment laboratory. And along with new equipment and infrastructure, a world of possibilities opens up. In addition to enabling the institute to work with such extreme pathogens as E. coli 0157 H, the new lab will help researchers explore critical issues such as the evolution of antibiotic-resistant bacteria. It will also help them track the spread of the West Nile virus, and to probe linkages between prions—the mysterious infectious agents responsible for several neurodegenerative diseases found in mammals—and Creutzfeld Jacob's diseases, also known as "mad cow disease."

"The problems associated with food safety are such that no one discipline can solve the problem," says Griffiths. "Having one single centre for food safety research will help us foster this inter-disciplinary approach to solving problems."

Creating and housing the institute will also assist Griffiths and his team in developing inter-disciplinary graduate programs. That way, says Griffiths, graduate students learn not only the hard science of microbiology, but also how to take a more holistic approach to food safety.


Safeguarding Health, Strengthening Industry

If we extrapolate from statistics in the United States, then every year as many as 7 to 10 million Canadians may suffer from some sort of foodborne illness. And since they often suffer without knowing it, most of these illnesses aren't even reported. That's because many of the associated symptoms mimic those of the flu, says Mansel Griffiths, a professor at the University of Guelph's Department of Food Science, and Director of the Canadian Research Institute for Food Safety.

And as the Canadian population ages and cancer, organ transplants, and other illnesses compromise more and more people's immune systems, Griffiths says the risks of contracting food-borne diseases increases.

The institute supports research designed to reduce the incidence of food- and water-borne illness. In an effort to better understand how these bacteria behave, investigators at the University of Guelph are pursuing research aimed at:

  • developing strategies to reduce the number of food-borne pathogens that animals carry;
  • drafting public policy advice and advocacy to safeguard the population;
  • inventing new techniques to detect and diagnose these illnesses;
  • studying the way bacteria adapt to their environments; and
  • investigating the reasons that "new" pathogens emerge, or why certain animal and human hosts are susceptible to them.

One of the reasons for tracking the source of food-borne illness outbreaks is to be able to prevent future events. And that's why the new equipment and infrastructure become so important. The secure containment laboratory at the food safety institute will enable researchers there to collect cultures and store samples so they can compare the genomes of different strains of microorganisms. They can then examine the way they are adapting and evolving.

Although this is all critical from a public health perspective, it will also have a significant impact on the strength and health of Canada's food and agricultural industries.

Increasingly, food safety and consumer concerns about the food supply are influencing trade in agricultural goods. Salmonella in poultry, Hepatitis A in strawberries, as well as E. coli and BSE (Bovine Spongiform Encephalopathy, better known as Mad Cow Disease) in beef have all ruined individual businesses and threatened to devastate the national economies in countries where the problems have been detected.

As part of its goal to stay strong and competitive, the Canadian food industry will benefit from the research performed at the food safety institute's facilities. Researchers will be able to make recommendations on everything including packaging, storage facilities, production processes, and on-farm environmental conditions.

"Fresh produce is now a fairly significant source of food-borne illness. So are ready-to-eat, minimally processed foods that the consumer can't do much to control," says Griffiths. "There is a new trend that's emerging in the problems that we've seen in food safety. It's important that the Canadian industry and the Canadian health agencies keep one step ahead of the game."


Working Together to Safeguard the Food Supply

Partnerships among government and academic resources—which eventually led to the identification of affected wells during the water contamination crisis in Walkerton, Ontario—are proving to be critical in investigating outbreaks of food-borne illness. The institute will help to foster these partnerships by attracting a critical mass of experts available to respond to situations like the Walkerton outbreak—in conjunction with both government and private-sector partners.

The food safety institute is a partnership between the University of Guelph, Health Canada, the Canadian Food Inspection Agency, Agriculture and Agrifood Canada, and the Ontario Ministry of Agriculture, Food and Rural Affairs. One of the areas of specialty the new institute will develop? Understanding the way microorganisms adapt to new processing conditions, such as non-thermal processing technology. The information the researchers accumulate will be important to Canada's food processing industry.

One of the advantages of having a highly visible food safety institute is that it will be one of the best-equipped food safety research centres in North America. It will also attract top-quality visiting researchers, as well as keep the best Canadian researchers right here at home.