Fecal contamination of seawater is widespread in the coastal ocean of the United States, causing illness and beach closures, impacting shellfish harvest, and degrading habitat. Human and animal feces pose different threats to human health, but epidemiological data that link human health outcomes to exposure in water do not distinguish human from animal feces. Current methods of measuring fecal contamination with public health indicator bacteria do not identify its source. Often fecal pollution cannot be corrected, because the source is not known. We have developed a rapid and accurate method of identifying the source of certain kinds of feces in water, utilizing a PCR assay that targets host-specific groups of Bacteroidetes fecal bacteria. The method differs from existing methods of detecting fecal pollution in that it detects genetic marker sequences that identify bacterial groups specific to the host species that produced the feces, allowing discrimination among different potential sources. This method performed well in a comparative study of fecal source tracking methods. Field studies in Tillamook Bay, Oregon, and Mission Bay, California, demonstrate this approach. The method has been tested throughout the U.S., in Canada, Ireland, and New Zealand. Utilizing the same technology, we also developed a quantitative (Q-PCR) assay for Bacteroidetes bacteria that is being tested as a rapid method of detecting fecal pollution. Both of these methods use small water samples, do not require isolating and growing bacteria, do not require a “library”, and are rapid and accurate.
Presenter:
Katharine G. Field, Ph.D.
Associate Professor
Department of Microbiology
Oregon State University
Tuesday January 11, 2005
POST 723
10:30 a.m.
Refreshments will be served after the seminar in POST 121
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation (OCE04-32479) and the National Institute of Environmental Health Sciences (P50ES012740).
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