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RECREATIONAL BEACH WATER QUALITY MONITORING WITH QUANTITATIVE POLYMERASE CHAIN
Citation:
HAUGLAND, R. A. RECREATIONAL BEACH WATER QUALITY MONITORING WITH QUANTITATIVE POLYMERASE CHAIN. Presented at Region 2 LTIG Conference, Newark, NJ, May 01 - 04, 2006.
Impact/Purpose:
The primary objective of this task is to identify, from a statistically significant pool of candidates, the fecal indicator microorganism(s) whose densities in recreational waters best correlate with the rates of illnesses monitored in the current health studies.
A second objective (pending the availability or development of suitable assays) will be to determine whether the rates of these illnesses are correlated with fecal pollution from humans or from various specific animal sources.
Description:
Recreational beaches are an important economic and aesthetic asset to communities, states and the nation as a whole. Considerable resources are expended each year in monitoring the water at these beaches for fecal indicator bacteria as a means of determining if it is safe for public use. Indicator bacteria measurements are presently performed by culture-based methods such as membrane filtration that require at least 24-hour before results are obtained. As a result, these methods often may not allow notification of potential health risks to swimmers until after exposures have occurred. Several molecular microbial analysis technologies have the capability of circumventing this deficiency by providing results in shorter time periods. One particularly rapid technology is the quantitative polymerase chain reaction (QPCR). Water analyses using this technology can provide results in approximately 2-4 hours. This technology has now been adapted for the measurement of the EPA-recommended fecal indicator organisms Eschericia coli and Enterococcus, as well as a promising new group of fecal indicator bacteria in the class Bacteroidetes, in surface water samples. In 2003-2004 studies were conducted by the U.S. EPA, Office of Research and Development (ORD), to determine the correlation between QPCR and EPA Method 1600 (membrane filtration) measurements of enterococci in water samples and swimmer illness rates at four Great Lakes beaches. Positive correlations were observed between the results of these two analytical methods and between the results of the QPCR method and swimmer illness rates. In 2005 a similar study was initiated for a marine beach on the Gulf of Mexico. This presentation will provide an overview of the ORD national beaches study, describe the QPCR method and its application for beach water quality analysis and discuss recent work on the optimization of assays and controls for use with different commercially available instrument and reagent systems.