Purpose: The purpose of this study was to quantify Salmonella transfer from contaminated gloves to cantaloupes, and vice versa, evaluating different contact times (5, 10, and 20 s) and pressures (none, mild, and vigorous).
Methods: Experiments were performed using store purchased cantaloupe with three types of gloves (nitrile, cotton, and rubber) typically worn by harvest crews. Two different transfer scenarios were evaluated: inoculated cantaloupe to clean glove and inoculated glove to clean cantaloupe. To simulate contamination in a dry environment, a dry inoculum protocol (inoculum mixed with sand) was used at a final concentration of 106 CFU/g. Salmonella populations from cantaloupes and gloves were enumerated on nonselective and selective agar supplemented with 50 µg/ml nalidixic acid. Transfer coefficients (TCs) were calculated, analyzed for analysis of variance, and significance was determined using least-squares significance test (P≤0.05) using SAS.
Results: Salmonella TCs were not significantly different between contact times for the two transfer scenarios. A positive association was observed between amount of contact pressure and Salmonella TCs. At vigorous pressure, rubber gloves transferred significantly more Salmonella to cantaloupes than nitrile and cotton gloves (P≤0.05). The rates of Salmonella transfer from inoculated cantaloupe to gloves were significantly higher than the rates of transfer from inoculated gloves to cantaloupe (P≤0.05). Similar to above, at vigorous pressure, cantaloupes transferred significantly more Salmonella to rubber gloves than nitrile and cotton gloves (P≤0.05).
Significance: The likelihood of Salmonella cross-contamination was influenced by different glove materials. Limiting the use of rubber gloves by harvest crews may minimize the risk of Salmonella transfer potential during field pack handling. The use of laundered cotton gloves or single-use nitrile gloves is recommended.