April 9, 2008

Canadian researchers discover anti-virulence determinant in salmonella
 

Researchers at Canada's University of British Columbia have discovered an anti-virulence determinant in salmonella, which could be used to produce improved salmonella vaccines.

Virulence factors allow a pathogen to thrive and cause disease in the host, whereas an anti-virulence factor controls the degree of infectiveness.

The finding suggests that there is a pathway in salmonella that acts as an anti-virulence factor and fine-tunes the host-pathogen balance during infection.

Research shows that the pathway is triggered before ingestion and entry into the intestine but stops once salmonella enters the intestine.

Salmonella becomes up to 10 times more virulent when the anti-virulence factor is shut down, according to Brett Finlay, professor of Microbiology and Biochemistry at UBC and senior investigator at the Michael Smith Laboratories. Finlay continued that salmonella could control its virulence even before it enters the host.

The pathway is designed to control the level of virulence and not to kill the host immediately, said Finlay.

The research will allow scientists to tailor the vaccine strain with the appropriate level of virulence, which will improve salmonella vaccines, said Finlay.