Escherichia coli

Escherichia coli (IPA: [ˌɛ.ʃəˈɹɪ.kjə ˈkʰoʊ.laɪ]) (E. coli), is one of the main species of bacteria living in the lower intestines of mammals, known as gut flora. When located in the large instestine, it actually assists with waste processing, vitamin K production, and food absorption. Discovered in 1885 by Theodor Escherich, a German pediatrician and bacteriologist,[1] E. coli are abundant: the number of individual E. coli bacteria in the feces that a human defecates in one day averages between 100 billion and 10 trillion.[citation needed] However, the bacteria are not confined to this environment, and specimens have also been located, for example, on the edge of hot springs. The E. coli strain O157:H7 is one of hundreds of strains of the bacterium that causes illness in humans.[2]

As with all Gram-negative organisms, E. coli are unable to sporulate. Thus, treatments which kill all active bacteria, such as pasteurization or simple boiling, are effective for their eradication, without requiring the more rigorous sterilization which also deactivates spores.