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Genetics in Water Quality and Public Health Microbiology

Researchers use microbial and molecular techniques as tools to manage beach water quality and to protect the public from swimming-related illnesses such as gastroenteritis.

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  Research Activities
Genetics and genomics USGS ecosystems research is supported by the USGS Ecosystems Mission Area.

Application of qPCR for Real-Time Monitoring of Recreational Water Quality
Beach goers at West Beach in Porter County, Indiana
Beach goers at West Beach in Porter County, Indiana

Recreational water quality is currently monitored for fecal indicator bacteria (E. coli or enterococci) to protect visitors from swimming-related illnesses such as gastroenteritis. Because the traditional culturing methods are time-consuming, often exceeding the rate of change for indicator bacteria, the U.S. EPA is currently revising the guidelines and considering the use of rapid methods (e.g., quantitative polymerase chain reaction qPCR) for indicator bacteria in beach waters. Recently, scientists with USGS examined the relationship between analytical outcomes using culture- and qPCR-based methods for enterococci in a variety of fresh and natural waters. Results indicated that the relationship was predictable but that the variation increased at lower concentrations of culturable enterococci. Overall, variation between samples was much higher for the qPCR-based results. Further research is needed to understand the relative contributions of analytical uncertainty, distribution and source of target bacteria, and antecedent environmental conditions.

See the project abstract:  Relationship and Variation of qPCR and Culturable Enterococci Estimates in Ambient Surface Waters Are Predictable

For more information contact Richard Whitman, Murulee Byappanahalli and Meredith B. Nevers.



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In the Spotlight USGS Scientist Katarzyna Przybyla-Kelly at a Lake Michigan beach collecting water sample that will be analyzed for enterococci using membrane filtration and quantitative PCR. Photo credit: USGS

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Page Last Modified: Monday January 14 2013