2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? The research falls within component 1.1 (Pathogens, Toxins and Chemical Contaminants, Preharvest) of NP 108. The project primarily addresses problem statement 1.1.2 (Epidemiology) in that it will provide an assessment of the potential for contamination of organic as compared to conventionally grown fresh market produce. It also addresses Problem Statement 1.1.4 (Interventions) in that it will provide information which may useful in minimizing the potential for contamination of fresh market produce. This project is aligned with National Program 108 Food Safety. Contamination of fresh produce with various gastrointestinal pathogens is responsible for many cases of human illness. Although most outbreaks are attributable to contamination during processing or preparation, recent reports have established the potential for contamination in the field prior to harvest. Pathogens contaminating the outer surfaces of leafy vegetables, edible roots, or fruits may pose a threat to human health if consumed without thorough washing. Alternatively, limited data suggests that enteric pathogens may also be able to invade and survive within the vascular tissue of produce. In this case, washing or cleaning will be ineffectual in preventing human exposure. Organic production practices have come under particular scrutiny due to the use of manures or manure-derived products, despite the existence of stringent guidelines regulating their use. However, there is currently inadequate data to assess the risk of in-field contamination with either organic or conventional practices. The goals of this research are to evaluate the various mechanisms of contamination in the field, the impact of different management systems on the likelihood of contamination, and potential intervention strategies to minimize human exposure. 2.List by year the currently approved milestones (indicators of research progress) Objective 1: Determine the prevalence, diversity, and quantity of bacteria associated with organic as compared to conventional fresh produce in MD and VA. Milestone 1: On-farm assessment of microbial ecology of pre-harvest produce and farm soil, water, and amendments. Sample produce, analyze, count, isolate, & identify microbial population patterns, at organic and conventional farm pairs in the growing season; summarize data, review and report results with basic statistical analysis, and review the need for adjustments at the end of year 1. Milestone 2: Repeat the on-farm assessment as in year 1 with any necessary adjustments; summarize data from year 2, including basic statistical analysis, and compare with year 1; review and report results and review the need for adjustments at the end of year 2. Milestone 3: Repeat the on-farm assessment as in years 1 and 2 with any necessary adjustments; summarize data from year 3 and compare with years 1 and 2; perform statistical analysis of all three years results; review and report results of all three years. Milestone 4: Perform statistical analysis of three years on-farm assessment results, by farm, by system, by commodity, relative to farm practices, location, weather events (floods) harvest time, and inputs. Write papers for peer-review journals by end of year 4. Milestone 5: Write papers on microbial community analyses from the on-farm assessment dataset (cultural and molecular data) for peer review journals (year 5). Objective 2: Determine colonization and survival rates of bacterial pathogens associated with selected organic and conventional raw produce. Milestone 1: Conduct growth chamber experiments to determine colonization (surface and internally) and survival rates of bacterial pathogens from polluted water and manure sources on selected organic and conventionally grown produce; include assessments of microbial ecology. Sample produce, analyze, count, isolate, & identify microbial population patterns among organic and conventional experimental units; summarize data, review and report results with basic statistical analysis (year 1). Milestone 2: Determine minimum inhibitory concentrations of essential oil supplements in Compost Teas containing E. coli O157:H7, Salmonella, and other pathogens; perform statistical analysis of all results; review and report results (year 1). Milestone 3: Determine the survival rates of epi- and endophytic bacteria associated with organic and conventional tomato plants (in growth chamber experiments) that are treated with manure-based compost tea; summarize data and report basic statistical analysis, report results at the end of year 2. Milestone 4: Establish field plots for future experiments (year 2). Milestone 5: Conduct field plot experiments that follow up on treatments from the growth chamber results (year 3). Milestone 6: Conduct field plot experiments that follow up on treatments from the growth chamber results (year 4). Milestone 7: Analyze results from field plot studies and prepare manuscripts for peer-review journals (year 5). Objective 3: Compare the extent of enteric pathogen transmission by a chewing insect, Colorado Potato Beetle, in organically- and conventionally-grown produce. Milestones 1 and 2: Conduct growth chamber experiments to determine colonization (surface and internally) and survival rates of bacterial pathogens vectored by Colorado potato beetles chewing on selected organic and conventionally grown produce; include assessments of microbial ecology. summarize data, review and report results with basic statistical analysis. (years 3 and 4) Milestone 3: Conduct field experiments to determine colonization (surface and internally) and survival rates of bacterial pathogens Colorado potato beetles chewing on selected organic and conventionally grown produce; include assessments of microbial ecology. summarize data, review and report results with basic statistical analysis. (year 5) 4a.List the single most significant research accomplishment during FY 2006. This is a new Project which was approved in April, 2006; consequently, there are no research accomplishments for FY06. 4d.Progress report. This project was initiated half-way through the current annual reporting cycle so the main accomplishments involve startup activities. These activities include completion of the restricted access growth chamber facility and finalization of endophyte extraction and cultivation protocols. 5.Describe the major accomplishments to date and their predicted or actual impact. This is a new Project which was approved in April, 2006; consequently, there is no major accomplishment to date. 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? This is a new Project which was approved in April, 2006; consequently, there is no major accomplishment to date.