Indicator bacteria

Indicator bacteria

Each gram of human feces contains approximately 12 billion (12*109) bacteria, among them may include pathogenic bacteria, such as "Salmonella", associated with gastroenteritis. In addition, feces may contain pathogenic viruses, protozoa and parasites. If ingested, these organisms would cause disease. When testing drinking water for contamination, the variety and often low concentrations of pathogens makes them difficult to test for individually. Health authorities therefore use the presence of other more abundant and more easily detected fecal bacteria as indicators of the presence of fecal contamination.

Indicator bacteria are not themselves dangerous to the health but are used to indicate the presence of a health risk.

The most popularized known indicator bacteria are fecal coliforms, which are found in the intestinal tracts of warm blooded animals. Another less commonly used group of indicator organisms are hydrogen sulfide producing bacteria, which are also found in humans as well as the intestinal tracts of birds and reptiles - known carriers of Salmonella.

WHO Guidelines for Drinking Water Quality state that as an indicator organism "Escherichia coliform" provides conclusive evidence of recent fecal pollution and should not be present in water meant for human consumption. It is generally assumed that higher the number of coliform organisms found in a 100L sample, the higher the risk for waterborne disease.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Indicator organism — Indicator organisms are used to measure potential fecal contamination of environmental samples. The presence of coliform bacteria, such as E. coli , in surface water is a common indicator of fecal contamination. Coliform bacteria in water samples …   Wikipedia

  • bacteria — bacterial, adj. bacterially, adv. /bak tear ee euh/,, sing. bacterium / tear ee euhm/. ubiquitous one celled organisms, spherical, spiral, or rod shaped and appearing singly or in chains, comprising the Schizomycota, a phylum of the kingdom …   Universalium

  • Coliform bacteria — Not to be confused with Coliiformes. Escherichia coli Coliform bacteria are a commonly used bacterial indicator of sanitary quality of foods and water. They are defined as rod shaped Gram negative non spore forming bacteria which can ferment… …   Wikipedia

  • Bacteriological water analysis — is a method of analysing water to estimate the numbers of bacteria present and, if needed, to find out what sort of bacteria they are. It is microbiological analytical procedure which uses samples of water and from these samples determines the… …   Wikipedia

  • Fecal coliforms — (sometimes faecal coliforms) are facultatively anaerobic, rod shaped, gram negative, non sporulating bacteria. They are capable of growth in the presence of bile salts or similar surface agents, oxidase negative, and produce acid and gas from… …   Wikipedia

  • Reclaimed water — Reclaimed water, sometimes called recycled water, is former wastewater (sewage) that has been treated to remove solids and certain impurities, and then allowed to recharge the aquifer rather than being discharged to surface water. This recharging …   Wikipedia

  • Hypochlorous acid — Hypochlorous acid …   Wikipedia

  • Aliso Creek (Orange County) — Not to be confused with Aliso Creek (Los Angeles County). Coordinates: 33°30′38″N 117°45′9″W / 33.51056°N 117.7525°W / 33.51056; …   Wikipedia

  • Life Sciences — ▪ 2009 Introduction Zoology       In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …   Universalium

  • method — The mode or manner or orderly sequence of events of a process or procedure. SEE ALSO: fixative, operation, procedure, stain, technique. [G. methodos; fr. meta, after, + hodos, way] Abell Kendall m. a …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”