Salmonella bugs could prevent food poisoning

Washington - The discovery of a "hypervirulent" Salmonella strain could help potentially prevent food poisoning outbreaks, a study reveals.

Previous efforts to find hypervirulent strains were unsuccessful since bugs behave much like their less-virulent cousins after environmental exposure.

"The trick was to assess their virulence during infection -- before they switch back to a less-virulent state in the lab," said study co-author Michael Mahan, professor at the University of California, Santa Barbara (UCSB).

Salmonella is the most common cause of infection, hospitalization, and death due to foodborne illness globally. This burden may continue to worsen due to the emergence of new strains that would tax current health-control efforts, the journal Public Library of Science Pathogens reported.

This problem egged the hunt for a hypervirulent strains of the bacteria by a team of scientists -- which included Robert Sinsheimer and William Shimp from the UCSB, John House from University of Sydney, Australia and others, according to a university statement.

Bacteria behave like a Trojan Horse, exposing their weapons only after initiating infection.

"These strains exhibit this behaviour in the extreme -- essentially having a '5th gear' they can switch to during infection," said Douglas Heithoff, from the UCSB, who led the study.

Now that researchers know what to look for, they are developing methods to rapidly detect and discriminate the more harmful strains from their less-virulent cousins.

Humans usually get Salmonella food poisoning from eating contaminated beef, chicken, or eggs. However, animal waste can contaminate fields where fruits, nuts, and vegetables are grown, thus posing a particular health concern for vegetarians.

The threat is exacerbated when these foods are not cooked. Salmonella control efforts are expensive -- recent estimates place this cost up to $14.6 billion annually in the US.