Listeria monocytogenes, biofilm formation and fresh cut produce

The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in freshcut produce are Listeria monocytogenes, pathogenic Escherichia coli, and Salmonella spp. Listeria monocytogenes is able to grow and multiply in vegetables packaged and stored in modified atmosphere. Biofilms formed by Listeria monocytogenes pose a serious threat to the safety of fresh cut produce as they can persist for long periods of time in the food processing environment and thus represent a source of recurrent contamination. Moreover the occurrence of naturally formed biofilms on fresh produce has been demonstrated. In this article the microbiological safety of fresh-cut produce and factors affecting Listeria monocytogenes survival and growth on fresh-cut produce are discussed. Moreover, the structure and physiology of Listeria monocytogenes biofilms are reviewed.