Definition - What does Coliform Bacteria mean?
Coliform bacteria are bacteria that are rod shaped and lactose fermenting. Coliform bacteria are not normally responsible for many serious diseases, although there are some strains which are pathogenic. They are easily cultured and commonly used as fecal indicators as their presence indicates that there are other pathogenic organisms originating from feces present as well. The most commonly used fecal indicator is the E-Coli family of bacteria, of which most strains are harmless.
Safeopedia explains Coliform Bacteria
Coliform bacteria are normally found in soil and vegetation, as well as the feces of most warm blooded creatures. They are often used to determine whether water is safe for human consumption. When the original test for the water is positive, further tests will be conducted on the water to determine the presence of specific pathogenic, illness causing organisms with fecal origins.