Water Resources Research Act Program

Details for Project ID 2006MN161B

Development of a DNA Marker Gene System to Determine Sources of Fecal E. coli in Watersheds

Institute: Minnesota
Year Established: 2006 Start Date: 2006-03-01 End Date: 2008-02-29
Total Federal Funds: $30,000 Total Non-Federal Funds: $85,816

Principal Investigators: Michael Sadowsky

Project Summary: The contamination of waterways with fecal material remains a persistent threat to public health. Identification of sources of fecal contamination is a vital component for abatement strategies and in the determination of total maximum daily loads. While phenotypic and genotypic techniques have been used to determine potential sources of fecal bacteria in surface waters, most methods require the construction of large known-source libraries, and often fail to adequately differentiate among environmental isolates originating from diverse animal sources. In contrast, library-independent, gene probe methods may provide a cost-effective approach to determine sources of environmental isolates originating from different animal sources. In this proposal, we will use the suppression subtractive hybridization technique to enrich for host source-specific DNA markers for E. coli originating from cows and humans. We have previously used this approach to identify DNA markers for E. coli originating from geese and have used these markers as gene probes in a library independent analysis of sources of E. coli in Lake Superior. The second objective of the proposed research is to use the newly identified DNA markers (and the existing goose marker gene) as gene probes to determine sources of E. coli in the Minneopa Creek watershed. Analyses will be done using a recently developed high throughput, automated, macroarray screening procedure. The identified markers will provide a quantitative, cost-effective, and accurate library-independent method to determine sources of genetically diverse E. coli for use in source tracking studies.