Title: Real-Time Monitoring of E. Coli Contamination in Wyoming
Project Type: Research
Start Date: 03/01/2006
End Date: 02/29/2008
Congressional District: 1
Focus Categories: Water Quality, Methods
Keywords: Water Quality Monitoring, Bacteria, Biomonitoring, Bioindicators
Principal Investigator: Johnson, Paul E.
Federal Funds: $17,950
Non-Federal Matching Funds: $96,638
Abstract: This project will demonstrate the feasibility of economical, simultaneous, real-time detection of individual Escherichia coli and their viability in surface waters. The Clean Water Act requires states to monitor surface waters for fecal coliforms or specifically for E. coli. Fecal coliform monitoring is an indicator of the sanitary quality of the water and can determine the extent of fecal contamination in the water from warm-blooded animals. A low-cost, portable, highly sensitive, self-contained single cell detection system for E. coli enumeration is being developed for rapid monitoring of surface waters, including streams, rivers, and lakes. With first-year USGS/WWDC funding, the P-I and his team have demonstrated and significantly improved an innovative technique for detection of pathogenic microorganisms in surface water, economically and in real time. This technology is based on LED-induced fluorescence of antibody- and DNA-labeled cells. The proposed project will demonstrate the detection of individual E. coli simultaneously in two wavebands in order to detect and determine viability of individual microorganisms. The suspended bacteria are stained using both an immunofluorescent antibody and a fluorescent cell viability label. The resulting aqueous sample is passed as a stream in front of an LED, which excites the fluorescent labels. The resulting fluorescence is measured with a CCD imager using an innovative integration scheme (called Fountain Flow), giving a dramatically higher signal-to-noise ratio than conventional techniques. In addition, we are investigating the extension of the fountain flow technology to imaging, to provide increased discrimination capability among E. coli, other biological particles, and small geological particles.
The major tasks of this project are to: 1.) fabricate and test a two-color, LED-illuminated detection system in order to simultaneously detect and determine the viability of E. coli, 2.) perform laboratory measurements on quantified E. coli samples to determine the detection efficiency and sensitivity of the two-color monitoring system, 3.) enumerate E. coli in stream and lake water samples using both our proposed method and the standard method currently recommended by the US Environmental Protection Agency, 4.) determine the feasibility of a rare-cell, fountain flow imaging system based on an extension of our current technology, and 5.) fabricate and test a prototype fountain flow imaging system for proof of concept.
Final Report, 2009, PDF