** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** E. COLI O157:H7 (ECO157) CONTAMINATION OF LETTUCE HAS BEEN A GRAVE CONCERN FOR DECADES, CAUSING NUMEROUS ILLNESS CASES AND FATALITIES, AND THUS THREATENING BOTH PUBLIC HEALTH AND A US INDUSTRY VALUED AT >$2 BILLIONANNUALLY. THIS FOOD SAFETY HAZARD IS TIED TO ECO157'S ABILITY TO COLONIZE THE SURFACE OF LETTUCE. THE COLONIZATION IS HIGHLY UNEVEN ON LEAF SURFACES AND INVOLVES INTERACTION WITH COMPLEX COMMUNITIES OF RESIDENT MICROBES INDIGENOUS TO LETTUCE (MICROBIOME). DESPITE THE MAGNITUDE OF HAZARD AND MOUNTING EVIDENCE THAT THE FATE OF IMMIGRANT ECO157 CELLS TO LETTUCE DEPENDS ON THEIR INTERACTION WITH THE NATIVE LETTUCE MICROBIOME, WHAT AND HOW SPECIFIC CONSTITUENTS OF THE RESIDENT MICROBIOME INTERACT WITH ANDAFFECT THE IMMIGRANT PATHOGEN REMAINS LARGELY UNEXPLORED.OUR LONG-TERM GOAL IS TO MITIGATE FOODBORNE PATHOGEN RISK OF LEAFY GREENS BY MODULATING THE PRODUCE MICROBIOME AND/OR OPTIMIZING PRODUCE PROCESSING ACCORDING TO THE MICROBIOME. IN THIS PROJECT, WE AIM TO SPATIALLY RESOLVE AND FUNCTIONALLY DISSECT ECO157-MICROBIOME INTERACTIONS AT THE RESOLUTION OF SINGLE BACTERIAL CELLS. USING A RECENT BREAKTHROUGH IN MICROBIOME IMAGING, WE WILL CREATE A BIOGEOGRAPHY OF THE LETTUCE MICROBIOME TO ADDRESS PREVIOUSLY INTRACTABLE QUESTIONS SUCH AS WHO IS THERE AND ALIVE, WHO INTERACTS WHOM, AND WHERE DOES THE INTERACTION OCCUR IN THE COMPLEX SURFACE TERRAIN OF LETTUCE. WE WILL ASSESS KNOWN AND NEWLY DISCOVERED RESIDENT BACTERIA THAT MAY HOLD PROMISE IN BIOCONTROL OF ECO157 (EFFECTOR STRAINS). WE SEEK TO IDENTIFY BIOLOGICAL MECHANISMS THAT MEDIATE THE INTERACTIONS ON BOTH SIDES OF THE MICROBIOME-ECO157 INTERPLAY. WE WILL ALSO DETERMINE THE EFFECT OF EFFECTOR STRAINS ON ECO157 SURVIVAL AND LOCALIZATION ON POST-HARVEST LETTUCE IN MODIFIED ATMOSPHERE PACKAGING DURING COLD STORAGE AND TEMPERATURE ABUSE. THROUGH THIS APPROACH, WE WILL PROVIDE A PROOF-OF-CONCEPT FOR THE FEASIBILITY OF POST-HARVEST MITIGATION OF ECO157 VIA MICROBIOME MANIPULATION.

University Of Georgia Research Foundation, Inc.

Investigators