Food bug might be adapting

Sanitation practices may no longer affect it, microbiologist says

SARAH SCHMIDT, Canwest News Service

Published: 12 hours ago


Source of Article:

A deadly bacterium at the centre of a growing food-borne outbreak might have figured out how to get around the best sanitation practices at Canada's meat-processing plants, one of the country's top food microbiologists says.

Rick Holley of the University of Manitoba says Maple Leaf Foods Inc. probably uses the best practices to make sure its meat products are safe, but nonetheless the company didn't catch the listeria contamination that has led to one of the country's largest food recalls. Twelve deaths have been blamed on listeria.

"Maybe the organism that we're looking at right now in this outbreak might be adapted to some peculiar way to have a higher tolerance to the sanitation activities, to the sanitation agents that are being used," Holley said.

"That would be unusual, but it's possible," said Holley, who chairs an international panel of experts on food safety management systems.

The team of 10 charged with food safety at the Toronto plant takes 3,000 swabs annually and analyzes them at the plant's in-house microbiology laboratory, looking for bacteria like Listeria monocytogenes, which can be deadly if they cling to food products and multiply as they sit on store shelves.

In this case, a government inspector stationed at the same plant also did not detect any gaps in the company's sanitation protocols that allowed the bacterium to grow; the cooking process kills listeria, but unlike most organisms, it likes salt and nitrate and can grow at refrigeration temperatures.

"We need to look very carefully at the effectiveness of what we consider to be acceptable programs in addressing this particular organism," Holley said.

"Normally, one could expect that such activities would detect the organism, but it will hide anywhere. Where you have a regular maintenance program for equipment combined with a regular sanitation program, you should be able to cover this off. The problem is the organism is coming in to the plant all the time and it's able under normal circumstances to survive in the meat plant and grow. We know that and Maple Leaf knows it ,too, and the only thing to address it is to put in place programs that will protect us," Holley said.

But the current outbreak is a signal that listeria, a type of bacterium often found in food and elsewhere in the natural environment, is currently able to crack through the best food-safety protocols in meat and cheese plants, he said.

"It probably gets through quite a bit. Is there more we can do? Yes, there is, but there are limits."

Lynn McMullen, a food microbiologist at the University of Alberta, says what makes the current outbreak so unusual is Maple Leaf Foods is "very good" at food-safety management.

"The organism had to be there somehow. It could be in a drain, it could be on a human, it could be any place, but often they target the drains because they'll find them in the drains. How that organism got from a drain to a food product is very difficult to figure out. This is something that is very unusual - it doesn't happen every day."

But McMullen said it's "very unlikely" we're looking at a superbug scenario comparable to a hospital setting.

"These organisms are everywhere in the environment. They don't need to adapt. The ones at the hospitals are adapting to antibiotic pressure. These guys don't have that kind of pressure. We don't do that in our food processing plants, so it's not a matter of them becoming a superbug in the same sense that the organisms in the hospitals are becoming. They're just a really resistant organism. They always have been, but the processors know how to deal with it, so this is a rare occurrence. I don't have any real quick and dirty 'Here's what they should have done' answers, because they just don't exist."

Richard Arsenault, who oversees meat inspection for the Canadian Food Inspection Agency, says he's not aware of red flags raised by any government inspector about the Maple Leaf plant.

"You have to make sure everything is basically spotless and is impeccable, probably cleaner than a surgical ward."

In this case, public-health officials first picked up there was a possible problem with food contamination last month when listeriosis cases started popping up in unusually high numbers of patients.

The rare but serious disease hits the elderly or people with a weakened immune system particularly hard; in serious cases, it can lead to brain infection and death.

Pregnant women are also vulnerable because infections can lead to miscarriage or stillbirth.




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