Featured Research

from universities, journals, and other organizations

Pathogenic E. Coli Pervasive In Stream-water Samples With Low Concentrations Of Fecal Indicator Bacteria

Date:
October 29, 2009
Source:
American Society of Agronomy
Summary:
Bacteria commonly used to indicate health risks in recreational waters might not be so reliable after all. Pathogenic E. coli were pervasive in stream-water samples with low concentrations of fecal indicator bacteria. This is one of the unexpected findings that may affect how we rely on indicator bacteria to determine if water is contaminated with bacteria that can make people sick.

Bacteria commonly used to indicate health risks in recreational waters might not be so reliable after all. Pathogenic E. coli were pervasive in stream-water samples with low concentrations of fecal indicator bacteria.

Related Articles


This is one of the unexpected findings from recent research that may affect how researchers and resource managers rely on indicator bacteria to determine if water is contaminated with bacteria that can make people sick. Although harmless themselves, fecal indicator bacteria such as nonpathogenic forms of E.coli, enterococci, and fecal coliform bacteria have long been used as an easy-to-measure surrogate to determine if pathogens are present.

“We saw little relation between pathogenic E. coli and fecal indicator bacteria criteria for recreational waters,” said Joseph Duris, U.S. Geological Survey (USGS), Michigan Water Science Center scientist who led the study. “This is intriguing because we rely on indicator bacteria to tell us whether or not the water could make people sick,” said Duris, whose study was published in the September-October issue of the Journal of Environmental Quality.

For this study, scientists collected water samples from 41 river sites in Michigan and Indiana from 2001-2003 and measured fecal indicator bacteria concentrations and markers of pathogens. Scientists grouped samples on whether or not they met recreational water quality criteria. The frequency of pathogen detection was compared between the sample groups.

Among the key findings:

  • Gene markers for pathogenic E. coli were pervasive in water from Michigan and Indiana streams even in water with low concentrations of fecal indicator bacteria.
  • Water samples exceeding the fecal coliform criteria for recreational water were significantly more likely to contain two of the tested pathogen markers. But for the three other tested pathogen markers, there was no significant difference between the groups.
  • There was no difference in the frequency of pathogen marker occurrence between groups based on exceeding the E. coli or enterococci indicator organism recreational water quality criteria.

In natural waters, low concentrations of fecal indicator bacteria, such as fecal coliform bacteria, E. coli and enterococci are presumed to indicate the absence of fecal inputs, and therefore, the absence of fecally-derived pathogens. However, the distribution of pathogenic bacteria in river systems and the relation of these bacterial pathogens to fecal indicator bacteria concentrations is poorly understood.

“We will need a more intensive study to determine what might be driving the relationship between fecal indicator organisms and pathogenic E. coli occurrence,” said Duris, whose team of USGS microbiologists completed the study with funding provided in part by the USGS Toxic Substances Hydrology Program.

The USGS Michigan Water Science Center is involved in several other studies investigating the relation between pathogen occurrence and fecal indicator bacteria criteria. National studies to assess the impacts of non-point source pollution are underway. Two regional studies are ongoing to investigate the occurrence of other bacterial pathogens including Salmonella, Shigella, and Campylobacter, and the pathogenic types of E. coli. Factors that could influence the occurrence of these pathogens in river systems, such as hydrology, season, land-use, and source are being investigated for relation with pathogen occurrence.


Story Source:

The above story is based on materials provided by American Society of Agronomy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joseph W. Duris, Sheridan K. Haack and Lisa R. Fogarty. How Good Are Indicator Bacteria at Predicting Pathogens in Recreational Water? J Environ Qual, Published online 23 July 2009; 38:1878-1886 (2009) DOI: 10.2134/jeq2008.0225

Cite This Page:

American Society of Agronomy. "Pathogenic E. Coli Pervasive In Stream-water Samples With Low Concentrations Of Fecal Indicator Bacteria." ScienceDaily. ScienceDaily, 29 October 2009. <www.sciencedaily.com/releases/2009/09/090922160106.htm>.
American Society of Agronomy. (2009, October 29). Pathogenic E. Coli Pervasive In Stream-water Samples With Low Concentrations Of Fecal Indicator Bacteria. ScienceDaily. Retrieved November 22, 2014 from www.sciencedaily.com/releases/2009/09/090922160106.htm
American Society of Agronomy. "Pathogenic E. Coli Pervasive In Stream-water Samples With Low Concentrations Of Fecal Indicator Bacteria." ScienceDaily. www.sciencedaily.com/releases/2009/09/090922160106.htm (accessed November 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, November 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Raw: Baby Okapi Born at Houston Zoo

Raw: Baby Okapi Born at Houston Zoo

AP (Nov. 20, 2014) The Houston Zoo released video of a male baby okapi. Okapis, also known as the "forest giraffe", are native to the Democratic Republic of the Congo in Central Africa. Video is mute from source. (Nov. 20) Video provided by AP
Powered by NewsLook.com
Your Complicated Job Might Keep Your Brain Young

Your Complicated Job Might Keep Your Brain Young

Newsy (Nov. 20, 2014) Researchers at the University of Edinburgh found the more complex your job is, the sharper your cognitive skills will likely be as you age. Video provided by Newsy
Powered by NewsLook.com
Mysterious Glow Worms Found in the Amazon

Mysterious Glow Worms Found in the Amazon

Buzz60 (Nov. 20, 2014) Wildlife photographer Jeff Cremer teamed up with entomologist Aaron Pomerantz and others to investigate a predatory glow worm found in the Amazon. Patrick Jones (@Patrick_E_Jones) explains. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins