Climate Change May Cause E. coli to Thrive, Researchers Warn

July 05, 2010 - News Release

Ten years after the Walkerton, Ont., tragedy, a University of Guelph professor says deadly E. coli bacteria adapting to a changing climate may pose new public health dangers to water and soil.

A new review paper co-authored by Prof. Jack Trevors, School of Environmental Sciences, warns that different forms of E. coli — particularly the pathogenic O157:H7 strain that killed seven people and sickened thousands more in Walkerton in 2000 — may find new ways to thrive in a warming environment.

The paper, titled “Survival of Escherichia coli in the Environment: Fundamental and Public Health Aspects,” appeared in June in The ISME Journal, published by the International Society for Microbial Ecology.

The paper was co-authored by researchers in the Netherlands and Portugal.

Changing climate and environment will likely trigger genetic changes in bacteria that could enable pathogens to survive in soil and water, potentially contaminating drinking-water sources.

“It’s a public-health alert," said Trevors, a microbiologist. "We have to be alert to possible new public health aspects.”

Public-health agencies, municipalities and operators of public and private water and waste-water systems need to pay more attention to infrastructure to prevent contamination, he said.

“The more we know about this, the better we can protect our water supply.”

The scientists reviewed existing research on genomic changes in E. coli, especially in the O157:H7 strain. That strain has developed tolerance for more acidic environments. That means the bug could more readily survive passage through the guts of animals and humans and enter the drinking-water system and farm fields.

They call for more study of the genetic ability of pathogenic bacteria to survive in open environments.

“We don’t know how organisms are going to respond to warming environments,” said Trevors.

This study was funded by the Security Through Science program of the North Atlantic Treaty Organization.

Prof. Jack T Trevors
School of Environmental Sciences
519-824-4120, Ext. 53367

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