Fecal Contamination - Human or Animal?
Microbial Source Tracking
When fecal contamination is found, a common question is whether the contamination is from a human or animal source.
Up until now, there was no simple bacteriological or chemical test to differentiate between human and animal fecal contamination. In the 1950's and 60's the Fecal Coliform to Fecal Streptococcus (FC:FS) Ratio was used to arrive at a determination. The theory being that human waste had a FC:FS ratio of more than 4:1. Animal waste had a FC:FS ration of less than 0.7.
However the FC:FS ratio was removed from "Standard Methods for the Examination of Water and Wastewater" in the 1970's when it was determined that the different species had significantly different die off rates in water. This caused the FC:FS ratio to shift and greatly limited its use.
Other methodologies have been attempted over the years with limited success.
Recently, Source Molecular Corporation of Miami, Florida led by Dr. Troy Scott, has developed a new technique for microbial source tracking (MST) called the Human Enterococcus "Quantification" IDTM.
This new technique along with others in their Human Fecal Pollution ToolboxTM has the potential to significantly advance the way we determine the sources of fecal contamination.
Using a standardized enterococci test and Polymerase Chain Reaction (PCR) DNA technology, this technique tests for a specific gene in the bacterium Enterococcus faecium, (the enterococcal surface protein or esp) that is a human source marker.
The test is rapid with results available in as little as 3 days.
With the initial bacteriological analysis being performed at Garden State Labs in New Jersey and the PCR analysis performed at Source Molecular you have the most accurate quantitation of enterococci organisms along with the latest in microbial source tracking.
If you have any question on this new technology, including fees and availability, call Harvey Klein, M.S., Laboratory Director, at the Lab at 800-273-8901 or email him at firstname.lastname@example.org. As is common with this type of laboratory analysis, fees are based upon sample volume.
Source Molecular has an excellent web site with detailed technical and scientific articles describing these new valuable additions to microbial source tracking. In addition to fecal contamination source tracking, they have techniques for Cryptosporidium and Giardia DNA analysis. We recommend that you visit their site to learn more about these exciting new techniques. www.sourcemolecular.com
Human Enterococcus "Quantification" IDTM
and Human Fecal Pollution ToolboxTM are trademarks
of Source Molecular Corporation, Miami, Florida.
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