The NFO reports that dangerous bacteria in a packaging station may hide under a biofilm of safe bacteria. This is based on the results of research done in three American apple packaging stations where Listeria had a persistent presence, despite disinfection. The research was carried out by the University of Pennsylvania. The findings of the research can be used to develop new strategies to prevent Listeria outbreaks and recalls in the future.
In one of the packing stations, where Listeria was found more than average, there were also more bacteria from the Pseudomonadaceae and fungus from the family Diposacaceae present. These microorganisms are very good at forming biofilms, often a slimy layer. Researchers believe that these innocent microorganisms promote Listeria by protecting it under a hard to penetrate biofilm. This may explain the persistence of Listeria in some packing stations.
These findings have prompted researchers to look into whether certain, safe, bacteria can function as the natural enemy of the Listeria bacteria.