Survival of Listeria monocytogenes and Salmonella on surfaces found in the dry packinghouse environment and effectiveness of dry-cleaning processes on pathogen reduction
Salmonella and Listeria monocytogenes are important foodborne pathogen involved in foodborne outbreaks linked to the consumption of produce and fresh fruits. Contamination of fresh produce is problematic since these products are usually consumed without heating. To avoid contamination events, the packing industry must rely on rigorous sanitation practices including in the dry areas of the packinghouse. This study proposes to develop informational tools regarding the die off rates of the pathogens exposed to matric stress. Experiments will reassemble packinghouse conditions. Dried planktonic cells and dried biofilms formed by the packing house microbiota and L. monocytogenes or Salmonella will simulate packing industry surfaces and environmental conditions. Experiments will investigate the conditions that favor transition of the planktonic cells present on surfaces to form attached embedded communities or biofilms, and formation of VBNC cells. Inactivation studies will provide data for best practices regarding dry cleaning/sanitation methodology in the packing house and elimination of the foodborne pathogens. These findings will be validated for practical use in the packing house, in a large pilot plant study to reduce the load of microorganisms on equipment and produce. Results from this study will provide improved pathogen control in addition to basic good agricultural practices.