Using whole genome sequencing (WGS), researchers from the University of Johannesburg have identified a trend of nonpathogenic Listeria strains developing concerning characteristics, such as virulence and stress resistance. Like the pathogenic L. monocytogenes, the “harmless” strains L. innocua and L. welshimeri are common to food processing facilities.

Whole genome sequencing (WGS) analyses have revealed pervasive Listeria monocytogenes strains to be an issue throughout the Norwegian food system, and researchers hypothesize that genetics may factor into which strains survive and spread in food production environments. 

A recently published review examines the history of foodborne illness outbreaks caused by Listeria monocytogenes in the UK, challenges that food manufacturers face when dealing with the pathogen, and potential future research and strategies related to the pathogen.