Difference between revisions of "Bacteria: Fecal Indicator Bacteria"

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According to studies conducted by the EPA, enterococci have a greater correlation with swimming-associated gastrointestinal illness in both marine and fresh waters than other bacterial indicator organisms, and are less likely to "die off" in saltwater. EPA has set health-based national recreational water quality standards of 35 colony forming units (CFU) per 100 milliliters (ml) of beach water sampled (30-day average) or 104 CFU per 100 ml (single sample standard).  The public is required to be notified if values exceed these limits. Note: The IDEXX tests report results as Most Probable Number (MPN) per 100 ml, which is equivalent to CFU per 100 ml.
 
According to studies conducted by the EPA, enterococci have a greater correlation with swimming-associated gastrointestinal illness in both marine and fresh waters than other bacterial indicator organisms, and are less likely to "die off" in saltwater. EPA has set health-based national recreational water quality standards of 35 colony forming units (CFU) per 100 milliliters (ml) of beach water sampled (30-day average) or 104 CFU per 100 ml (single sample standard).  The public is required to be notified if values exceed these limits. Note: The IDEXX tests report results as Most Probable Number (MPN) per 100 ml, which is equivalent to CFU per 100 ml.
  
Surfrider's [http://www.surfrider.org/whatwedo3c.asp Blue Water Task Force] performs beach water tests for total coliform and E. coli (a subset fecal coliform) using IDEXX's Colilert test or for enterococcus using IDEXX's Enterolert test to evaluate the levels of these indicator bacteria in recreational waters.
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Surfrider's [http://www.surfrider.org/blue-water-task-force Blue Water Task Force] performs beach water tests for total coliform and E. coli (a subset fecal coliform) using IDEXX's Colilert test or for enterococcus using IDEXX's Enterolert test to evaluate the levels of these indicator bacteria in recreational waters.
  
 
Also see our articles on [[Epidemiological Studies]] and [[Health Threats from Polluted Coastal Waters]].
 
Also see our articles on [[Epidemiological Studies]] and [[Health Threats from Polluted Coastal Waters]].

Revision as of 00:24, 20 April 2011

Coliform Bacteria

Coliform Bacteria Tester

The quality of marine and other recreation waters is usually determined through testing for the presence of indicator bacteria. The indicator bacteria that are most commonly examined are called "Coliforms". Coliform bacteria originate from soils, plants and human and animal wastes. Although not all coliforms are harmful to humans the presence of high numbers of coliforms in a water body is a good indicator that the water is polluted with harmful microorganisms and viruses.


Fecal Coliform Bacteria

Fecal Coliforms are a specific kind of coliform bacteria that are found primarily in the intestinal tracts of mammals and birds. These bacteria are released into the environment through human and animal feces. The presence of fecal pollution may come from storm water runoff, pets and wildlife, and human sewage. If they are present in high concentrations in recreational waters and are ingested while swimming or enter the skin through a cut or sore, they may cause human disease, infections or rashes.

One species of fecal coliform bacteria is the infamous E. coli bacteria, a specific strain of which has been linked to numerous foodborne illness outbreaks in the United States.

A number of other bacteria in combination comprise the Fecal Coliform group. In other words, E. coli is not a direct substitute for Fecal Coliform. E. coli can comprise anywhere from 5% to 90% of the Fecal Coliform in the water and often ranges from 80 - 90% of the Fecal Coliform.

Used together, total coliform and fecal coliform bacteria levels are an important tool that help scientists determine whether it is safe to surf and swim at the beach.

Enterococcus

The enterococcus group is a subgroup of the fecal streptococci. The enterococci portion of the streptococcus group is a valuable bacterial indicator for determining the extent of fecal contamination of recreational surface waters. Studies in marine and fresh waters indicate that enterococci are one of the best bacterial indicators of water quality. Enterococcus is a bacteria found in the human intestine and therefore a good indicator of human waste.

According to studies conducted by the EPA, enterococci have a greater correlation with swimming-associated gastrointestinal illness in both marine and fresh waters than other bacterial indicator organisms, and are less likely to "die off" in saltwater. EPA has set health-based national recreational water quality standards of 35 colony forming units (CFU) per 100 milliliters (ml) of beach water sampled (30-day average) or 104 CFU per 100 ml (single sample standard). The public is required to be notified if values exceed these limits. Note: The IDEXX tests report results as Most Probable Number (MPN) per 100 ml, which is equivalent to CFU per 100 ml.

Surfrider's Blue Water Task Force performs beach water tests for total coliform and E. coli (a subset fecal coliform) using IDEXX's Colilert test or for enterococcus using IDEXX's Enterolert test to evaluate the levels of these indicator bacteria in recreational waters.

Also see our articles on Epidemiological Studies and Health Threats from Polluted Coastal Waters.


This article is part of a series on Clean Water which looks at various threats to the water quality of our oceans, and the negative impacts polluted waters can have on the environment and human health.

For information about laws, policies, programs and conditions impacting water quality in a specific state, please visit Surfrider's State of the Beach report to find the State Report for that state, and click on the "Water Quality" indicator link.