Efficacy and Mechanisms of Power Ultrasound Based Hurdle Technology for Reduction of Pathogens in Fresh Produce

Bacterial pathogens such as Escherichia coli O157, Salmonella enterica and Listeria monocytogenes are frequently implicated in foodborne disease outbreaks linked to various minimally processed fresh produce, causing thousands of cases of human infections in the U.S. and have become an eminent public concern for food safety. The overall goal of this project is to develop and validate an effective "hurdle technology" based on combined use of a newly developed continuous flow power ultrasound wash system and chemical sanitizers to reduce bacterial pathogens on fresh produce surface under realistic, plant-scale produce washing conditions. Molecular and next-gen RNA-sequencing technologies will be used to elucidate mechanisms underlying the survival and persistence of different human outbreak-associated bacterial pathogens on treated fresh produce as well as in wash water as a "persistent" environmental reservoir for cross contamination. This project will provide much needed validation data for an innovative and sustainable intervention technology to improve the microbial safety of minimally-processed fresh produce. This project will also fill important knowledge gaps regarding the mechanisms of pathogen survival and persistence during fresh produce processing.