Listeria monocytogenes is prevalent in retail produce environments but Salmonella enterica is rare

Publication date: Available online 19 February 2020Source: Food ControlAuthor(s): John Burnett, Sophie Tongyu Wu, Henk C. den Bakker, Peter W. Cook, Deklin R. Veenhuizen, Susan R. Hammons, Manpreet Singh, Haley F. OliverAbstractThe purpose of this study was to determine the prevalence of Listeria monocytogenes and Salmonella enterica in retail produce environments and to elucidate possible ecological niches. Thirty environmental samples per store were collected during daily operations monthly for six months in 30 retail produce departments across seven states. Selected samples were serially diluted and plated to determine aerobic plate count. Each sample was tested for L. monocytogenes and S. enterica using ROKA Atlas LmG2 and SEN assays, respectively. A total of 5,112 samples were tested for each pathogen. S. enterica was found during one sampling event in a single store; less than 0.1% of samples were positive overall. A total of 4.4% environmental samples tested positive for L. monocytogenes. L. monocytogenes was present on 8.1% of non-food contact surfaces and 1.6% of food contact surfaces tested; L. monocytogenes prevalence was highly variable among stores. Most of the positive L. monocytogenes samples were found in drains, floors, squeegees, or standing water. Genetically similar L. monocytogenes clones were found in multiple stores across multiple states. The odds of detecting L. monocytogenes increased 1.8-fold for every 1-log increase in APC (p < 0.0001). Thi...
Source: Food Control - Category: Food Science Source Type: research