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Influence of the Pre-Harvest Environment on the Physiological State of Salmonella and Its Impact on Increased Survival Capability

Harris, Linda
University of California - Davis
Start date
End date
Salmonella spp. has been implicated in numerous outbreaks of foodborne illness tied to the consumption of fresh fruits, vegetables, and nuts, seeds and spices. Multistate outbreaks of salmonellosis due to consumption of tomatoes, mangos, melons and raw almonds have highlighted the ability of Salmonella to persist in a wide range of pre- and postharvest environments. Exposure to large swings in moisture, temperature, and nutrient levels are expected in these environments. The relative tolerance to these conditions is known differ among strains of Salmonella. In addition, some of the environmental stressors may trigger a variety of survival response mechanisms in some strains providing further competitive advantage. While strain dependent survival phenomena have been documented, the mechanism of these differences is not clear.

The proposed research seeks to increase our understanding of the environmental factors that trigger survival mechanisms in outbreak-related strains of Salmonella and to better elucidate those mechanisms related to desiccation tolerance and environmental persistence.

The results will help the produce industry to better interpret Salmonella-positive test results and should assist in making informed decisions related to preand postharvest risks of contamination.

Funding Source
Center for Produce Safety
Project source
View this project
Project number
Bacterial Pathogens
Nuts, Seeds