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Evaluation of Fecal Indicator and Pathogenic Bacteria Originating from Swine Manure Applied to Agricultural Lands Using Culture-Based and Quantitative Real-Time PCR Methods
PEED, L., C. A. KELTY, M. SIVAGANESAN, T. Mooney, O. C. SHANKS, AND S. Rogers. Evaluation of Fecal Indicator and Pathogenic Bacteria Originating from Swine Manure Applied to Agricultural Lands Using Culture-Based and Quantitative Real-Time PCR Methods. Presented at American Society for Microbiology 110th General Meeting, San Diego, CA, May 23 - 27, 2010.
Fecal bacteria, including those originating from concentrated animal feeding operations, are a leading contributor to water quality impairments in agricultural areas. Rapid and reliable methods are needed that can accurately characterize fecal pollution in agricultural settings. Our study examines runoff from swine manured agricultural lands, comparing traditional culture-based methods with PCR and quantitative real-time PCR (qPCR) approaches. Four small experimental watersheds (1.5 to 2 acres) planted with corn were used for this study. The watersheds were designed so that all runoff flows through a single focal point at the edge of each field, where flow-weighted average samples were collected during each runoff event using Coshocton wheel samplers. Two watersheds received swine manure at a rate of 160 lbs N/acre. Two additional watersheds served as unmanured controls, receiving only chemical fertilizer. A total of 113 runoff samples were collected over a range of runoff intensities spanning a 12 month period. All runoff samples were analyzed with six PCR and eight qPCR assays detecting general fecal indicators including E. coli, enterococci, Bacteroidales, as well as human, cattle, and swine host-associated genetic markers. Culture-based methods were used to measure E. coli and enterococci bacteria concentrations and to detect the presence or absence of Salmonella and E. coli O157:H7 fecal pathogens. Our results indicate discharge of unsafe levels of fecal indicators and pathogens during initial runoff events. The concentrations of viable fecal indicator bacteria cells and fecal bacteria genetic markers in subsequent runoff events attenuate at different rates suggesting that these indicators do not share similar fates in manured soils. Notice - Although this work was approved by EPA for publication, it may not reflect official Agency policy.
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Record Details:Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
WATER SUPPLY AND WATER RESOURCES DIVISION
MICROBIAL CONTAMINANTS CONTROL BRANCH