Preventing Pathogen Transport to Southern Piedmont Landscapes from Poultry Production Systems

With the Poultry Microbiological Safety Research Unit, we will assess pathogen movement in the landscape and develop collaboration with new partners. Existing field sites will be used to determine what organisms are in the environment. Molecular techniques will be explored for source identification of pathogens. Salmonella, Campylobacter and Clostridia will be studied and practices developed to eliminate these pathogens from poultry litter. Impacts of landscape position, vegetation, and soil properties on pathogen persistence and transport will be investigated. Solute transport models will be modified to describe organism movement in surface and subsurface water. Hydrologic models will be linked with baseline data to develop control strategies. After initial studies, analyses will be conducted of indirect risks, such as toxic algae that may result from nutrient-enriched aquatic ecosystems.

PROGRESS: 1999/10 TO 2000/09
1. What major problem or issue is being resolved and how are you resolving it? In 1998, the U.S. poultry industry produced 12 Tg (>13 million tons) of broiler litter, most of which was applied to agricultural fields within fifteen miles of its production. Broiler litter, like all animal manures, is a source of plant nutrients, but it is also a source of pathogenic bacteria like Salmonella, Campylobacter, and Clostridium perfringens. Broiler litter is also a source of sex hormones. Both pathogenic microorganisms and sex hormones may be transferred from crop and pasture lands to surface and ground waters that are used for recreation or drinking, and thus, pose an environmental health risk to humans as well as wild and aquatic life. Information on the fate and transport of pathogens and sex hormones from poultry litter is needed. Our research focuses on methods to identify and reduce transmission of pathogens, and sex hormones from poultry litter to runoff, streams, ground water, irrigation water, crops, and food producing animals. We will 1. conduct baseline assessment of pathogens in Southern Piedmont watersheds and landscapes where high levels of poultry production occur, 2. develop methods for sample collection from diverse field environments and for source identification of organisms, 3. elucidate the transport processes and degradation of sex hormones from poultry litter, 4. elucidate pathogen fate and transport processes within the environment and determine filtering effectiveness of different soils and vegetation, 5. develop management systems for handling and land application of poultry manure and litter that protect environmental quality and food safety. 2. How serious is the problem? Why does it matter? Thousands of Americans become ill each year through exposure to organisms that are known to exist in animal manures, including poultry. Much of the manure is applied to crop and pasture land to provide plant nutrients, but little is known about the risks of survival and transport of pathogens in the environment that might be associated with land applications of manure. Because of concern about the presence of endocrine disrupters (chemicals that mimic sex hormones) in the environment, and suggestions that these chemicals lead to decreased sperm counts in men, prepubescent development in children and widespread disorders in a variety of wildlife, the presence of the actual sex hormones in broiler litter cannot be ignored. With poultry litter applications on agricultural fields these hormones can potentially appear in soil, groundwater, and surface water. A better understanding of potential environmental and human health risk associated with on-farm handling and land application of poultry litter is needed in order to reduce these risks. Producers need cost-effective and safe ways to utilize nutrients in manures to improve sustainability of their systems. This research should contribute to sustained poultry production and income to rural communities and safe, healthy, and economical food and water supply for consumers. The research will support Federal action and regulatory agencies, including the USDA-Natural Resource Conservation Service and the Environmental Protection Agency, and provide technical expertise to better respond to national food safety and environmental emergencies. 3. How does it relate to the National Program(s) and National Component(s)? This research investigates survival and transport of pathogenic bacteria, and sex hormones associated with poultry litter that is applied to agricultural lands. These investigations relate directly to the Pathogen Component of the National Program 206, Manure and Byproduct Utilization. It is part of the Food Safety Initiative funded by Congress in FY99 to initiate a broad, integrated research program to address health and environmental concerns associated with food production systems in the US. It supports directly the Food Safety National Program 108 (Microbial Pathogen Component). This research will make contributions to National Program 205 (Rangeland, Pastures and Forages), National Program 207 (Integrated Farming Systems), and National Program 201 (Water Quality and Management). 4. What were the most significant accomplishments this past year? A. Single Most Significant Accomplishment During FY 2000: We prepared a draft five-year project statement that successfully underwent agency review in early FY2000. Under that plan, we have established new experiments on long-term watersheds and are developing new experimental watersheds to study land application of poultry litter to crops and winter pasture. Projected outcomes of this new research are better methods to collect environmental samples to monitor pathogens, methods for source identification of organisms found in environmental samples, knowledge of survival and transport of pathogens in the environment, knowledge of transport and fate of sex hormones from poultry litter, and development of improved management practices to reduce environmental and health risks. This research should directly contribute to reduced environmental and human health risk associated with US poultry production systems. B. Other Significant Accomplishments: The presence of Escherichia coli, and Enterococci in surface waters is indicative of fecal contamination. We initiated bi-weekly baseline monitoring of E. coli and Enterococci at 25 locations in the Upper Oconee River Basin. In collaboration with Dr. Peter Hartel, University of Georgia, and others, we have developed ribotyping methods to identify host species of E. coli that may allow source identification of contaminants in the future. The application of ribotyping indicator bacteria will identify the source of the organisms, and thus identify a nonpoint source. For ribotyping to be a reliable tool for identifying sources of fecal contamination, ribotypes must display stability over time. We thus initiated a study of the temporal variability of E. coli ribotypes associated with cattle. Preliminary analysis of the data indicate that there are two components to E. coli ribotypes of cattle, a stable resident component and a fluctuating nonresident component. This project will be the first study to determine if E. coli ribotypes associated with a specific animal remain stable over time and can be used to identify a source of fecal contamination within a defined region. C. Significant Accomplishments/Activities that Support Special Target Populations: 5. Describe the major accomplishments over the life of the project including their predicted or actual impact. Research was initiated that was integrated with landscape hydrology, nutrient cycling, grazing systems, and water quality research. The work was also integrated with research in the Poultry Microbiological Safety Research Unit in Athens, GA. Michael B. Jenkins was recruited as a Category 1 microbiologist, and started on September 26, 1999. We developed a position description for a Biological Science Research Technician (Microbiology); it was filled by Tracy Olexa. The microbiology laboratory was developed at Watkinsville to support the new research. Conservation practices are needed to reduce the movement of microbial pathogens from grazing lands into the surface waters of the USA. We examined the impact of farm ponds and associated stream buffers on losses of E. coli and enterococci bacteria from grazing lands. Numbers of microbes in the stream above the pond were elevated by grazing animals but in the outflow of the pond numbers were lower than observed in a wooded creek without domestic animals. This work is currently being presented to the community of producers and researchers interested in protecting water quality and may provide an economic and effective means of limiting losses of pathogens to the environment. 6. What do you expect to accomplish, year by year, over the next 3 years? Project was replaced with new CRIS-6612-42000-032 7. 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 & durability of the technology product? Because we use participatory approaches to our research, technology transfer to poultry producers, farmers who land apply poultry litter, other industry people, and state and federal agencies occur throughout the research process. The baseline assessment that we have initiated is needed to ascertain the highest priority issues to address in this new research program and the technology transfer program is being designed in conjunction with end-users. Many of the poultry producers are small farmers who have limited capital resources and operate on very tight economic margins, so the systems and technologies must include low-cost options that can be maintained by farmers who may also have off-farm jobs. 8. List your most important publications in the popular press (no abstracts) and presentations to non-scientific organizations and articles written about your work (NOTE: this does not replace your peer-reviewed publications which are listed below) Hartel, P.G., Segars, W.I., Stern, H.J., Steiner, J., Buchan, A. Ribotyping to determine the host origin of Escherichia coli isolates in different water samples. p.377-382. In: (Olsen, D.S., Potyondy, J.P. Eds.) Wildland Hydrology. American Water Resources Association, Herdon, Virginai, TPS- 99-3. 1999. p.536.