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News Release

November 01, 2006

New Research Has Disease-Fighting Potential

A new find by an international research team that includes University of Guelph microbiologists could help fight deadly disease-causing bacteria.

The scientists’ discovery of a novel bacterial protein complex may ultimately help in designing drugs to disable pathogens that cause a range of disorders such as meningitis, blood diseases and hospital-acquired infections, said Chris Whitfield, a professor in Guelph’s Department of Molecular and Cellular Biology who is leading one of the two teams involved in the research.

The research was published today in Nature. It was authored by Whitfield and U of G post-doctoral researchers Jutta Nesper, Anne Brunkan-LaMontagne and Brad Clarke, along with a research team at the Centre for Biomolecular Sciences at the University of St. Andrews in Scotland.

The research team described the first structure representing a previously unknown class of membrane proteins essential in allowing pathogens to elude host immune defences. This protein enables the bacteria to move large, complex sugar-containing molecules called polysaccharides through the cell membrane. Once on the cell surface, these long polymer chains make a protective “coat” against the immune system.

“This protein breaks the rules as we knew them,” said Whitfield. “It’s effectively a new way to make a membrane channel. While we had many working models for the protein, the final structure was a real surprise. It is a beautiful example of nature’s ability to find elegantly simple solutions for complex biological problems.”

The discovery may give researchers a new target for antibiotics intended to prevent the polymers from passing through bacterial membranes. Alternatively, drug companies may devise new ways to keep large membrane channels fixed open – another strategy that may prove just as lethal to pathogens.

The U of G research was supported by the Canada Foundation for Innovation and the Canadian Institutes of Health Research (CIHR).

"The work of Dr. Whitfield and his team demonstrates the importance of collaboration in expanding our knowledge of how bugs evade the body’s host defence," said Dr. Bhagirath Singh, Scientific Director of the CIHR Institute of Infection and Immunity. "Their research findings may allow the development of new treatments for diseases such as meningitis and hospital-acquired infections."

The work may also attract food manufacturing companies who harness bacteria with a similar membrane transport process to make xanthan gum, which is used to thicken and stabilize dairy products and salad dressings. Whitfield said these companies might use his team’s work to learn how to increase yields of xanthan or its modified products.

As holder of the Canada Research Chair in Molecular Microbiology, He is interested in how bacteria selectively allow extremely large and complex polymers to pass out of the cell while keeping out potentially harmful molecules at the same time.

“This recent discovery represents a massive step forward in our understanding," said Whitfield. "The challenge for us now is to learn how to exploit it. We hope that will come from the next few years of research.”