U of G Scientist Expanding Research on E. coli

June 02, 2011 - News Release

A University of Guelph food scientist wants to learn more about deadly E. coli bacteria, including a strain linked to organically grown vegetables that has killed at least five people and sickened hundreds more in Europe.

Calling the disease an emerging food safety issue, Prof. Keith Warriner said we need to know more about the pathogen, including its source and persistence in the environment. That information will help the food industry refine control measures. He’s especially interested in the so-called “top six” types of E. coli that are known to cause hemolytic uremic syndrome (HUS), as well as the O104:H4 version implicated in the German outbreak.

About 600 cases of E. coli infection were confirmed late last month in Germany, with more reports from Britain, the Netherlands, Sweden and Denmark. More than 250 cases have led to HUS, which can cause kidney failure, strokes and seizures.

Until now, HUS has been associated mostly with E. coli O157:H7. In 2000, that strain killed seven people and sickened thousands of others in Walkerton, Ont., after contamination of the town’s water supply.

Besides O157:H7, more than 200 kinds of E. coli contain genes to make a toxin called shiga. Most of these shiga toxin-producing E. coli (STECs) cause no illness or induce symptoms no more serious than those of the 24-hour flu, said Warriner.

“In recent years, there has been a dramatic increase in the number of illnesses of non-O157 STECs that can lead to serious outbreaks as being observed in Germany,” he said. “More worrying is that the deadly non-O157 STEC can affect broad host ranges and is not limited to the elderly or young.”

Regulators want to screen for the “top six” non-O157 types, but tests for E. coli O157:H7 cannot be used for these six strains, said Warriner. A test is available to identify those six non-O157 serotypes, but it would have missed the O104 strain in Germany.

“We need more reliable and sensitive tests to identify the pathogenic STEC from less significant serotypes.”

A Canadian survey done 10 years ago found the pertinent strains in 40 per cent of beef cattle.

Warriner hopes to work with experts in microbiology, food engineering and epidemiology at several agencies, including Agriculture and Agri-Food Canada, the Ontario Ministry of the Environment, the Public Health Agency of Canada, and U of G’s Laboratory Services Division.

He will discuss his work during a health symposium hosted by U of G’s Centre for Public Health and Zoonoses June 9. For information, visit www.ovc.uoguelph.ca/cphaz/.

For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, lhunt@uoguelph.ca, or Deirdre Healey, Ext. 56982, d.healey@exec.uoguelph.ca.

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