Evaluation of the Level of White-tailed Deer Fecal Colonization by E. coli O157:H7 and the Ecological Role of Dung Beetles with the Pathogen in Produce Farms

Wildlife as a source of microbial contamination is a concern among public health and food safety agencies. Deer feces have, on multiple occasions, been determined as the source of E. coli O157:H7 contamination of produce. We plan to use the lowbush blueberry agroecosystem as a conceptual model system in which to test some broadly applicable, food safety questions. We will evaluate the level of white-tailed deer fecal colonization by E. coli O157:H7 and to explore seasonal dynamics of E. coli O157:H7 contamination within feces. Additionally, we feel it is important to understand dung beetles’ ecological role as a potential natural control agent of the pathogen, alternatively as a pathogen vector between feces and fruit, or as a potential pathogen reservoir. Understanding the level of white-tailed deer fecal colonization by E. coli O157:H7 and subsequently, the ecological role of dung beetles in agriculture has strong implications for any system in which vegetables or fruits are at risk of wildlife fecal contaminants. We plan to determine the levels of pathogenic E. coli O157:H7 in deer fecal samples associated with the full geographic range of Maine’s lowbush blueberry. In addition we plan to conduct a laboratory study to elucidate dung beetle ecology as it relates to the suppression and/or transmission of pathogens.
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We will use the full range of Maine’s lowbush blueberry crop and prevalent white-tailed deer feces as a conceptual model system in order to develop a sampling protocol for examining the levels of pathogens in wildlife feces within agricultural systems. We will determine the level of white-tailed deer fecal colonization by E. coli O157:H7 within the context of the lowbush blueberry system and seek to, eventually, extend these methods to other systems. We will develop a model relating potentially heightened seasonal prevalence of E. coli O157:H7 found in deer feces with harvest period of lowbush blueberry. We will test for contamination of any blueberry from sample sites of any feces samples testing positive to E. coli O157:H7 in order to explore the relationship between fecal contamination and fruit contamination. This will have powerful monitoring and management implications. Lastly, we will perform a lab study to determine ecologically important dung beetle/E. coli O157:H7/fruit relationships.
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The anticipated result of our proposed research on the produce industry is to provide information that will allow the quantification of risk due to E. coli O157:H7 contamination of deer feces in fruit and vegetable fields. In addition, we aim to determine seasonal dynamics of E. coli O157:H7 contamination within feces and provide proof of concept for novel ideas in understanding the ecological role of dung beetles in suppression and/or transmission of pathogens.