Foodborne pathogen sheltered by harmless bacteria that support biofilm formation

Pathogenic bacteria that stubbornly lurk in some apple-packing facilities may be sheltered and protected by harmless bacteria that are known for their ability to form biofilms, according to Penn State researchers, who suggest the discovery could lead to development of alternative foodborne-pathogen-control strategies.

That was the key finding that emerged from a study of three tree-fruit-packing facilities in the Northeast where contamination with Listeria monocytogenes was a concern. The research, done in collaboration with the apple industry, was an effort to better understand the microbial ecology of food-processing facilities. The ultimate goal is to identify ways to improve pathogen control in the apple supply chain to avoid foodborne disease outbreaks and recalls of apples and apple products.

In the study, researchers sought to understand the composition of microbiota in apple-packing environments and its association with the occurrence of the foodborne pathogen Listeria monocytogenes. Their testing revealed that a packing plant with a significantly higher Listeria monocytogenes occurrence was uniquely dominated by the bacterial family Pseudomonadaceae and the fungal family Dipodascaceae.

Biofilms are a collection of microorganisms that attach to a surface and then secrete a slimy material that slows down the penetration of cleaners and sanitizers. The findings of the research provide insight into the Listeria contamination problem and may lead to researchers and the apple industry getting closer to solving it.

The challenge presented by microbiota possibly sheltering Listeria monocytogenes is not limited to fruit-processing facilities or produce, Penn State researchers suspect.

See:

Xiaoqing Tan, Taejung Chung, Yi Chen, Dumitru Macarisin, Luke LaBorde, Jasna Kovac. The occurrence of Listeria monocytogenes is associated with built environment microbiota in three tree fruit processing facilities. Microbiome, 2019; 7 (1) DOI: 10.1186/s40168-019-0726-2

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology