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Overall goals: This proposed project will integrate applied research and outreach education to (i) gain a more comprehensive understanding of pathogen persistence, including transmission dynamics of persistent strains within food processing plants and risk factors associated with cross-contamination of foods by persistent strains (ii) populate and promote the utilization of a publicly available database that permits anonymous deposition of subtype, source and temporal data for key foodborne pathogens, to facilitate identification and surveillance of foodborne pathogen strains that persist in a food processing plant and (iii) develop and deliver outreach training sessions (i.e., in-plant trainings, webinars, workshops and symposia) to augment knowledge regarding pathogen persistence, as well as to communicate risk factors for cross-contamination of food products by persistent strains and mitigation strategies to control pathogen persistence <P>
Objectives: Objective. I. Perform longitudinal studies in meat and seafood processing plants to detect L. monocytogenes, Salmonella and pSTEC in the plant environment and food products. Objective. II. Subtype isolates from Obj. I to identify persistent strains, elucidate persistent strain transmission dynamics, including risk factors for persistence and cross-contamination of food products. Objective. III. Extend knowledge regarding persistence of pathogens in food processing plants, including risk factors for persistence and mitigation strategies to control persistent strains. Outcomes: Through the use of combined field studies and molecular subtyping to characterize L. monocytogenes, Salmonella and pSTEC isolates from the food processing plant environment and their associated food products, our project will provide a greater understanding of factors that contribute pathogen persistence in the food processing plant environment and elucidate the transmission dynamics of pathogens in the plant environment. Results from field studies and molecular characterization will be critically evaluated to identify risk factors for pathogen persistence and cross-contamination of food products by persistent strains, including identification of mitigation strategies to control pathogen persistence. Our team will conduct training sessions (i.e., in-plant trainings, webinars, workshops and symposia) and develop training materials (e.g., fact-sheets, presentations and hands-on activities) to disseminate general knowledge regarding pathogen persistence in the food chain and communicate mitigation strategies to control pathogen persistence with specific emphasis on eliminating harborage sites and interrupting transmission of strains that persist in the plant environment to food products.
NON-TECHNICAL SUMMARY: Recent multistate outbreaks of foodborne illness attributed to cross-contamination of foods by persistent Listeria monocytogenes or Salmonella strains highlight the continued need for research and training on L. monocytogenes persistence and current knowledge gaps regarding Salmonella and Escherichia coli O157:H7 persistence. The overall goal of this project is to integrate applied research and outreach to augment knowledge regarding pathogen persistence. We propose to conduct combined field studies and molecular subtyping to identify persistent L. monocytogenes, Salmonella and E. coli O157:H7 strains to probe risk factors for persistence and pathogen phenotypes that may contribute to persistence. Knowledge gained will be disseminated to food processors and trainers through a series of outreach activities designed to provide fundamental knowledge regarding pathogen persistence, identification of persistent strains and monitoring transmission patterns, risk factors for persistence and mitigation strategies to control persistence. <p/>
APPROACH: Objective I. We will identify and enroll at least four fresh meat, RTE meat and RTE seafood plants each in a longitudinal study where environmental and food product samples will be collected from each plant on a bi-monthly basis for a two-year period. Data on plant demographics, production and sanitation practices will be collected through the use of a standardized questionnaire and these data will be compared as detailed in Obj. II to identify plant factors associated with pathogen persistence. Objective II. We will perform pulsed field gel electrophoresis (PFGE) typing of L. monocytogenes, Salmonella and pSTEC isolates I following standard CDC PFGE protocol. We will also compare data from plant survey questionnaires collected in Obj. I to the nature of persistent colonization of each plant by the pathogens targeted in this study along with contamination patterns for each plant. Objective III. We will (i) regularly communicate testing and molecular subtyping results to each plant enrolled in this study and conducting in-plant training sessions to critically evaluate contamination patterns in each plant (ii) develop short fact-sheets on pathogen persistence in food processing plants and (iii) conduct a web-based seminar (webinar) series to provide information on pathogen persistence in processing plants and (iv) develop and deliver workshops and symposia targeted towards industry and trainers, providing information on pathogen persistence.<p/> PROGRESS: 2011/11 TO 2012/10<br/>
OUTPUTS: Dr. Nightingale and Dr. Wiedmann incorporated teaching modules on molecular methods in food microbiology in courses they teach, team-teach or deliver guest lectures for at Texas University and Cornell University, respectively. Dr. Nightingale delivers lectures on molecular detection and subtyping of foodborne pathogens for the following courses; Food Safety and Food Microbiology. Dr. Wiedmann delivers guest lectures on molecular detection and subtyping of foodborne pathogens for graduate level courses at Cornell University. PARTICIPANTS: Texas Tech University: Kendra Nightingale and Sarah Navratil. Cornell University; Martin Wiedmann, Travis Chapin, Laura Strawn, Rachel Pfuntner, and Ester Fortes. TARGET AUDIENCES: Target audiences include other academic researchers as well as food industry and government agencies that use molecular methods for detection and further characterization of foodborne pathogens and spoilage organisms. PROJECT MODIFICATIONS: Not relevant to this project.
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IMPACT: 2011/11 TO 2012/10<br/>
Approximately 3,000 environmental samples from productions agriculture environments (i.e., produce fields and grazing pastures) and pristine environments (i.e., national parks and wildlife feeding areas) were collected in upstate New York and Colorado each. Environmental samples (i.e., drag-swab, water, soil, and fecal pat/dropping samples) were microbiologically analyzed to detect important foodborne pathogens, including Listeria monocytogenes, Salmonella, and pathogenic shiga toxin encoding Escherichia coli. Isolates have been stored at either Cornell or Texas Tech University and will be characterized by phenotypic (serotyping) and molecular (Pulsed field gel electrophoresis and targeted DNA sequencing) subtyping. Findings from sample collections efforts and characterization of pathogen isolates will be submitted as abstracts to be presented at a scientific meeting in 2013 (e.g., International Association of Food Protection or American Society for Microbiology).