New insights into cross-contamination of fresh-produce

Cross-contamination is a primary cause of pathogen contamination in fresh-produce affecting any point of its production-distribution chain. This work provides a review of the latest research on cross -contamination in vegetables and fruits based on laboratory data, epidemiological information, and predictive models. Importantly, the review stresses the paramount impact of water-mediated microbial transfer on prevalence levels of pathogens in produces during industrial water-based processing. This increasing effect on prevalence and the low infective dose of some pathogens can bring to light the prime role of cross-contamination in the illness burden and the large outbreaks usually linked to produces. The use of disinfectants can reduce but not eliminate cross-contamination, being largely influenced by other factors (organic load, produce/ water ratio, produce surface, time, etc.). Produce preparation areas can also play a leading role due to the formation of cross -contamination ecosystems, making microbial transfer possible in any direction, involving different sources, utensils, fomites, and handling practices, as well as affecting different food batches. Therefore, unraveling and understanding the complexity of the cross-contamination pathways in food preparation areas should be considered as a priority. A myriad of variables can reduce or enhance microbial transfer efficiency, including cells' adhesion, chemical and physical properties of the produce and abiotic surfaces, moisture content, contact pressure and time, biofilm, aggregative cell structures, handling practices, and so on. More mechanistic predictive models such as agent-based approaches are needed to overcome experimental limitations and data gaps. Models, if accessible, may be used as simulation bench to assist decision-makers in testing different control measures and interventions, identifying the most effective strategies to reduce cross-contamination.