Estimating Salmonella transfer rates between inoculated ground beef and food contact surfaces with varying contamination levels and serotypes

Abstract

Salmonella remains a leading cause of foodborne illness associated with beef products. Cross-contamination during food handling represents a critical pathway for transmission. While previous studies have evaluated the individual factors that could influence Salmonella transfer, there is limited research examining the combined effects of serotype, inoculation level, and surface type on cross contamination dynamics. Therefore, the objective of this study is to simulate conditions of a typical consumer home kitchen setting to better evaluate how different bacterial levels (high, medium, and low) of distinct Salmonella serotypes (Typhimurium, Infantis, Newport, and Dublin) and surface material (hands, wood, plastic, and patty) contribute to cross-contamination. Significant differences (P<0.0001) were observed among all three interactions (serotype, treatment, surface). Data presented as percent transfer revealed that transfer efficiency remained consistently high across all surfaces, within treatment, and within serotype. Nearly all observations, with exception to the Mitt sample, approached nearly 100% transfer, indicating minimal loss of microbial level during the processing steps. Although serotype-specific differences were detected, particularly for Salmonella Dublin, these did not substantially alter the observed patterns of transfer. Overall, these findings demonstrate that Salmonella can be transferred readily between surfaces with high efficiency regardless of initial contamination level, serotype, or surface type. From a food safety perspective, these results underscore the importance of strict hygiene and sanitation practices, as even low levels of contamination may spread and contribute to foodborne illness, particularly in consumer homes.