WATER RESOURCES RESEARCH GRANT PROPOSAL
Project ID: 2005WY24B
Title: Real-Time Monitoring of E. Coli Contamination in Wyoming
Project Type: Research
Focus Categories: Water Quality, Methods
Keywords: Water Quality Monitoring, Bacteria, Biomonitoring, Bioindicators
Start Date: 03/01/2005
End Date: 02/28/2006
Federal Funds: $35,500
Non-Federal Matching Funds: $79,088
Congressional District: 1
Paul E. Johnson
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. Fecal contamination is important from a public standpoint when the surface water’s designated use includes contact recreation such as beach use, boating, or swimming. It has been shown that E. coli enumeration is more accurate than fecal coliform enumeration in assessing the potential of surface waters to transmit infectious diseases to humans via contact recreation. A low-cost, portable, highly sensitive, self-contained single cell detection system for E. coli enumeration is proposed for rapid monitoring of surface waters, including streams, rivers, and lakes. With previous USGS/WWDC funding, the P-I and his team have demonstrated an innovative technique for detection of pathogenic microorganisms in surface water, economically and in real time. This technology is based on laser-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 propose to investigate 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 will be 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 4.) fabricate and test a prototype fountain flow imaging system for proof of concept.
Final Report, 2009, PDF