Coliform bacteria are a commonly used bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

l indicator

Indicator bacteria

Indicator bacteria are types of bacteria used to detect and estimate the level of fecal contamination of water.Each gram of human feces contains approximately ~100 billion bacteria . These bacteria may include species of pathogenic bacteria, such as Salmonella or Campylobacter, associated with...

 of sanitary quality of foods and water. They are defined as rod-shaped Gram-negative

Gram-negative

Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

 non-spore forming

Endospore

An endospore is a dormant, tough, and temporarily non-reproductive structure produced by certain bacteria from the Firmicute phylum. The name "endospore" is suggestive of a spore or seed-like form , but it is not a true spore . It is a stripped-down, dormant form to which the bacterium can reduce...

 bacteria which can ferment lactose

Lactose

Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

 with the production of acid and gas when incubated at 35-37°C. Coliforms can be found in the aquatic environment, in soil and on vegetation; they are universally present in large numbers in the faeces of warm-blooded animals. While coliforms are themselves not normally causes of serious illness, they are easy to culture and their presence is used to indicate that other pathogenic organisms of faecal origin may be present. Faecal pathogens include bacteria, viruses, or protozoa and many multicellular parasites.

Typical genera include:

• Citrobacter
  Citrobacter
  Citrobacter is a genus of Gram-negative coliform bacteria in the Enterobacteriaceae family.The species C. amalonaticus, C. koseri, and C. freundii use solely citrate as a carbon source...
  
  ,
• Enterobacter
  Enterobacter
  Enterobacter is a genus of common Gram-negative, facultatively-anaerobic, rod-shaped bacteria of the family Enterobacteriaceae. Several strains of the these bacteria are pathogenic and cause opportunistic infections in immunocompromised hosts and in those who are on mechanical ventilation...
  
  
• Hafnia
  Hafnia (bacterium)
  Hafnia is the genus of the Enterobacteriaceae family whose only species is the Gram-negative, facultatively anaerobic, rod-shaped bacterium Hafnia alvei....
  
  
• Klebsiella
  Klebsiella
  Klebsiella is a genus of non-motile, Gram-negative, oxidase-negative, rod-shaped bacteria with a prominent polysaccharide-based capsule. It is named after the German microbiologist Edwin Klebs...
  
  
• Serratia
  Serratia
  Serratia is a genus of Gram-negative, facultatively anaerobic, rod-shaped bacteria of the Enterobacteriaceae family. The most common species in the genus, S. marcescens, is normally the only pathogen and usually causes nosocomial infections. However, rare strains of S. plymuthica, S. liquefaciens,...
  
  
• Fecal coliform:
  • Escherichia
    Escherichia
    Escherichia is a genus of Gram-negative, non-spore forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, Escherichia species provide a portion of the...
    
    

Escherichia coli

Escherichia coli

Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

(E. coli), a rod-shaped member of the coliform group, can be distinguished from most other coliforms by its ability to ferment lactose at 44°C in the fecal coliform test, and by its growth and color reaction on certain types of culture media. When cultured on an EMB plate, a positive result for E. coli is metallic green colonies on a dark purple media. Unlike the general coliform group, E. coli are almost exclusively of fecal origin and their presence is thus an effective confirmation of fecal contamination. Some strains of E. coli can cause serious illness in humans.

See also

• Bacteriological water analysis
• Coliform index
  Coliform Index
  The coliform index is a rating of the purity of water based on a count of fecal bacteria. Coliform bacteria are microorganisms that primarily originate in the intestines of warm-blooded animals...
  
  
• Fecal coliform
• Indicator bacteria
  Indicator bacteria
  Indicator bacteria are types of bacteria used to detect and estimate the level of fecal contamination of water.Each gram of human feces contains approximately ~100 billion bacteria . These bacteria may include species of pathogenic bacteria, such as Salmonella or Campylobacter, associated with...