Cow Microbial Source Tracking Case Studies

Detect Cow Fecal Load, Quantify % Cow Contamination, Multiple Samples Recommended

Cow MST Case Studies 2017-06-28T18:27:18+00:00

Cattle MST Case Studies

1. Cattle Markers Exceed Water Quality Criteria in Brandywine Creek

Water samples taken from the Brandywine Creek Basin in Delaware that exceeded the E. coli and the Enterococci recreational water-quality criteria (RWQC) more frequently contained markers of cattle feces or bovine sources, according to a study released in 2011 by the U.S. Department of the Interior and the U.S. Geological Survey in cooperation with the City of Wilmington, Delaware.

The study entitled, “Pathogenic Bacteria and Microbial-Source Tracking Markers in Brandywine Creek Basin, Pennsylvania and Delaware, 2009–10,” was intended to help in understanding the occurrence and distribution of fecal indicator bacteria (FIB), fecally derived pathogens, and potential fecal sources that contribute to microbial water-quality impairments.  “Brandywine Creek drains a mixed-land-use basin that contains agricultural, urban, and suburban areas and has within it several wastewater-treatment discharges and industrial and public-supply withdrawals.  The City of Wilmington, Delaware, which is in the downstream part of the basin on the main stem of Brandywine Creek, uses the stream for its main drinking-water supply.”

The City of Wilmington, which has been investing in best-management-practices (BMP) projects in the Brandywine Creek since 2005, was interested in determining the potential sources of the fecal pollution and pathogens in the basin.  Researchers sampled water monthly for one year during high flow and normal flow at five routinely sampled sites within the basin as well as three additional sites located upstream of the West and East Branches.  “The collected samples were analyzed for the densities of the FIB, Escherichia coli (E. coli), Enterococci, and fecal coliform bacteria.  DNA extracted directly from each water sample was analyzed for the quantity of each of three types of Bacteroides microbial source tracking (MST) markers indicating general, bovine, and human fecal pollution.”

One of the study’s findings was that the E. hirae bovine fecal marker was found more frequently in the West Branch than the East Branch during high flow.  Researchers believe this indicates that elevated FIB densities in the West Branch are more frequently related to bovine sources than in the East Branch.  Researchers also found that water from the West Branch that was carrying FIB of bovine origin spilled over to other areas triggering positive results in those sites at certain times.

A copy of the study is available here.

2. Two Ditches in Northwestern Ohio Tested Positive of Cow Manure

Cattle fecal contamination was detected in water samples collected at certain sites in the Portage River Watershed in Northwestern Ohio, according to a study released in 2010 by the U.S. Department of the Interior and the U.S. Geological Survey in cooperation with Bowling Green State University and the Wood County Health Department.

USGS hydrologists Christopher M. Kephart and Rebecca N. Bushon investigated the usefulness of microbial source tracking (MST) with host-associated molecular markers to characterize cattle and human-origin fecal contamination in the Portage River watershed.  They concluded that results support the utility of using MST with host-specific molecular markers to characterize the sources of fecal contamination in the Portage River watershed.  Concerns were raised on the influx of concentrated animal feeding operations in northwest Ohio and this prompted local agencies to examine the effects of these industrial farms on water quality in the upper Portage River watershed.

A total of 13 fecal source samples and 17 water samples were tested for the presence and relative quantity of MST markers by quantitative polymerase chain reaction (qPCR).  Sample collection of potential fecal sources (treated wastewater, septage, and cattle slurry) was done on November 6, 2007, while the water samples were collected on June 26, 2008, and September 15, 2008.  The study detected the presence of the bovine-associated Bacteroides (BoBac) marker at the Poe Ditch site and the Huffman Ditch site in the Portage River watershed, which result was both expected and unexpected.  At other sites thought to be affected by animal fecal contamination, the BoBac marker was either undetected or at low concentrations.  Researchers note that their study provides (i) a foundation from which future investigations could be conducted concerning fecal contamination in the Portage River watershed and (ii) background information on putative sources and sites that may be helpful in future investigations in the watershed.

A copy of the study is available here.

3. One-Third of Altamaha River Water Samples Positive of Cattle Virus

Bovine enteroviruses were detected in 11 of 30 surface water samples collected monthly from five tidally influenced stations at the Altamaha River in Georgia between July and December 2002, according to study conducted by researchers from the Department of Environmental Health Science of the University of Georgia and the United States Geological Survey’s Florida Integrated Science Center for Coastal and Watershed Studies.

The study, published in 2004, developed and used molecular assays targeting human enteroviruses (HEV), bovine enteroviruses (BEV), and human adenoviruses (HAdV) to identify major sources of fecal contamination in the lower Altamaha River, the largest river of the Georgia coast and the second largest basin in the eastern United States.

Two-liter grab samples were collected from five stations along a 15-km stretch of the lower Altamaha River, located between Glynn and McIntosh counties, in conjunction with the Georgia Marine Extension Service, Brunswick.  Reverse transcriptase polymerase chain reaction (RT-PCR) for bovine enteroviruses was performed.  The study noted that viral pathogen detection by PCR is a highly sensitive and easy-to-use tool for rapid assessment of water quality and fecal contamination when public health risk characterization is not necessary.

Researchers noticed that detection of bovine enteroviruses increased at lower water temperatures and increased streamflow, particularly during the months of November and December while bovine enteroviruses were not detected in July and August samples.  “This finding is consistent with previous reports that the stability of viral particles is highly influenced by water temperature.  Increase in streamflow may have caused more remote influx of contaminants as well as more widespread viral loading.”
Non-point source cattle fecal contamination in the Altamaha River Basin may be attributed to land application of manure, runoff from confined animal feeding operations, and perhaps unconfined cows inhabiting the marsh islands surrounding the sampling stations in the lower Altamaha River.

A copy of the study is available here.