Peters, Kenlyn Eve2017-07-072019-06-082017-05-30Peters_cornellgrad_0058F_10269http://dissertations.umi.com/cornellgrad:10269bibid: 9948886https://hdl.handle.net/1813/51663The purpose of this study was to contribute to the understanding of the presence of foodborne pathogens at different levels in the food supply chain of animal origin and the potential factors associated with their risk, and possible mechanisms of disease in humans. Given the broad spectrum of the issue, this study focuses on bacterial pathogens among different aspects of the food chain in the diverse State of Qatar, including animal, human and retail samples, and among conventional and organic dairies in New York State. Using a combination of bacterial enrichments, biochemical and agglutination tests, and molecular detection, the presence of pathogens was tested for among samples taken from farms, slaughterhouses, retail stores and restaurants and from fecal samples obtained from humans admitted to hospitals with cases of gastroenteritis in Qatar, and milk and milk filter samples from conventional and organic dairies in New York. Other shiga toxin-producing serotypes are becoming nearly as much of a concern as the more commonly known E. coli O157:H7. The presence of the cytolethal distending toxin (CDT) in isolates recovered from gastroenteritis cases suggests a role in the pathogenesis of the condition. Furthermore, the detection of CDT among food animal isolates along the food supply chain highlights the potential zoonotic risk. Being exposed to foodborne pathogens can increase the risk of chronic gastroenteritis sequelae, including Inflammatory Bowel Disease.en-USE. coliEpidemiologyAnimal sciencesMicrobiologyCampylobacterCytolethal Distending ToxinFoodborne PathogensSalmonelladissertation or thesishttps://doi.org/10.7298/X4HQ3X1X