Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How Good Are Indicator Bacteria at Predicting Pathogens in Recreational Water?

24.09.2009
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 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.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://jeq.scijournals.org/cgi/content/abstract/38/5/1878.

The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | Newswise Science News
Further information:
http://www.agronomy.org

More articles from Agricultural and Forestry Science:

nachricht Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University

nachricht New machine evaluates soybean at harvest for quality
04.10.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>