Preservation microbiology and safety: Evidence that stress enhances virulence and triggers adaptive mutations

Bacteria present in food systems are frequently subjected to stresses that are purposefully placed in the food systems as barriers to their growth. Studies using modern gen tic tools are pointing to the fact that while such barriers play a vital role in preventing the outgrowth of pathogenic bacteria, in certain cases, the virulence of the stressed pathogen:; may increase. In short, the bacterium's environment may 'arm' that bacterium to survive similar stresses encountered in the human host. In this Viewpoint article, I wish to focus on the ability of environmental stress to modulate bacterial virulence, and also to act as a potential driving force promoting adaptive mutations that may serve to select strains that are even more virulent.