Purpose: The purpose of this study was to identify cantaloupe contact surfaces in retail environments for both whole and fresh-cut cantaloupe and determine the presence of microorganisms, including Listeria, on such surfaces.
Methods: A total of 141 environmental samples were collected using Dey/Engley sponge swabs from seven contact surfaces at four time points in five food retail locations during the fall of 2016. Swabs were homogenized with peptone water and plated on ECC for coliforms and Eschericia coli, TSA for total aerobic count, MOX for Listeria spp., and LMPM for Listeria monocytogenes.
Results: Approximately 32% (45 of 141) of swabs tested positive for Listeria spp.; no L. monocytogenes positive sample was recovered from any of the surfaces. Surfaces associated with whole cantaloupe contact had higher prevalence of Listeria spp. with 73.7% (28 of 38) testing positive. Surfaces associated with fresh-cut production had a comparatively lower prevalence of Listeria (17.9%; 17 of 95). One sample (0.71%) tested positive for E. coli. Surfaces that were regularly cleaned showed a decrease in coliform levels after sanitation. Whole cantaloupes were placed on top of foam to provide cushioning and prevent bruising. This foam had a high prevalence of Listeria, with 100% (19 of 19) swabs testing positive for Listeria spp.
Significance: No samples tested positive for L. monocytogenes and only one sample tested positive for E. coli. Additionally, cleaned surfaces showed a reduction in coliform counts, suggesting effective cleaning practices. Areas associated with whole cantaloupe use are more likely to be contaminated with Listeria spp. Foam, which was rarely cleaned, was found to be a harborage point for Listeria spp.