Persistence of Salmonella Enterica and Listeria Monocytogens in Agricultural Soils: Focus on Bio-Mitigation Strategies to Expedite Replantin

Producers of fresh fruits and vegetables need practical and sustainable methods to minimize the survival and persistence of human pathogens, such Salmonella and Listeria monocytogenes in soil. Soil contamination with these human pathogens represents a major problem for the fresh produce supply chain because of the lack of valid remediation strategies that growers could implement to reduce and/or eliminate the presence of naturally occurring human pathogens. Soil contamination with Salmonella and Listeria monocytogenes across major production regions within the U.S has resulted in numerous acres of abandoned crops including leafy greens and melons. Destruction of multiple fields or contaminated crops due to human pathogen contamination has initiated a decline in the economy of many states not only due to the loss of high cash crops but also to increased environmental damage owed mainly to the use of non-sustainable practices. Our research will focus on three main objectives: 1- studying the prevalence of Salmonella enterica and Listeria monocytogenes on farm land used for leafy green and melon production that utilize uncomposted manure following the 90 to 120day rule for organic productions. 2- We will use this information to develop challenge studies where the persistence of Salmonella enterica and Listeria monocytogenes will be assessed after the application of three intervention strategies: - cover cropping, 2- solarization and 3- the incorporation of grape pomace and mushroom compost to soil mesocosms. These first two objectives are fundamental to understand the mechanisms determining pathogen die-off in soils and therefore increase our ability to formulate effective and sustainable preharvest interventions necessary to sustain fresh produce supply across the U.S. 3- Identify and quantify the costs to farmers required to implement and maintain the recommended mitigation practices within their cropping system. . This last objective will allow us to establish the potential long term economic impact of these new remediation practices on farmer's income and how this new economic expense compares with land abandonment and loss in productivity. Combining this research approach with tangible economic metrics will allow us to provide growers with science-based tools that could salvage their economic livelihood. We aim to increase safety involved in produce and fruit production through implementing sound and sustainable farm practices that can be applied to any cropping system across the U.S.