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Updated: Jul 14, 2026
11:29
Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses
Published on: December 3, 2011
Microbial source tracking in a rural watershed dominated by cattle
A K Graves1, C Hagedorn, A Brooks
1Department of Soil Science, North Carolina State University, Campus Box 7619, Raleigh, NC 27695-7619, USA. alexandria.graves@ncsu.edu
Water Research
|June 22, 2007
Summary
Antibiotic resistance analysis (ARA) in a Virginia watershed revealed cattle as the primary source of fecal pollution, impacting water quality year-round. Sampling frequency and seasonality did not affect these microbial source tracking results.
Area of Science:
- Environmental microbiology
- Water quality assessment
- Antimicrobial resistance
Background:
- Rural watersheds can experience significant fecal pollution from livestock.
- Assessing the sources of this pollution is crucial for effective water management.
- Antibiotic resistance analysis (ARA) offers a method for microbial source tracking (MST).
Purpose of the Study:
- To evaluate the effectiveness of ARA for MST in a cattle-dominated watershed.
- To determine the impact of sampling frequency and seasonality on MST results.
- To identify the primary sources of fecal coliform pollution in Mill Creek, Virginia.
Main Methods:
- Monthly monitoring of fecal coliforms and targeted stream sampling during high and low flow periods.
- Development of a host-origin library using ARA on known bacterial isolates.
- Classification of Escherichia coli isolates from water samples using the ARA library.
Main Results:
- Cattle were identified as the dominant source of pollution, contributing to over 60% of water samples.
- Recreational water quality standards for fecal coliforms were frequently exceeded, particularly during low flow.
- Sampling frequency and seasonality did not influence the identification of cattle as the major pollution source.
Conclusions:
- ARA is a reliable method for identifying fecal pollution sources in well-defined watersheds.
- Cattle significantly impact water quality in the Mill Creek watershed, irrespective of sampling strategy.
- Further investigation is needed to determine the origin of unexpected human fecal contributions.
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