Bacterial stress response in Listeria monocytogenes:: jumping the hurdles imposed by minimal processing

Minimal processing relies on the use of multiple sub-lethal stresses (or processes) to achieve a similar level of microbial control as that traditionally achieved using a single lethal stress. The benefit to the consumer is products which are less obviously processed than a frozen or canned, acidified or heavily salted food item. However, our increasing understanding of haw bacteria can adapt to sub-lethal stresses in a manner which can render them less susceptible to additional insults, should be borne in mind when designing safety or extended shelf-life into a minimally processed product. Listeria monocytogenes is a target organism for many minimally processed food manufacturers because of its ability to tolerate adverse conditions such as low Aw and low temperature. In this communication we use L. monocytogenes as a model system to describe some of the consequences of stress adaptation in terms of improved survival in minimally processed foods and, importantly, the consequences in terms of the virulence of the target organism. (C) 2002 Elsevier Science Ltd. All rights reserved.