Escherichia coli are bacteria found in the environment, foods, and intestines of the people and animals. E. coli are large and diverse group of bacteria. Although most strains of E.coli are harmless, others can make you sick. some kinds of E. coli can cause diarrhoea, while others cause urinary tract infections, respiratory illness and pneumonia, and other illnesses.
E. coli and other facultative anaerobes constitute about 0.1% of gut microbiota, and fecal-oral transmission is the major route through which pathogenic strains of the bacterium cause disease. Cells are able to survive outside the body for a limited amount of time, which makes them potential indicator organism to test environmental samples for fecal contamination. A growing body of research, through has examined environmentally persisten E.coli which can survive for and grow outside a host.
The bacterium can be grown and cultured easily and inexpensively in a laboratory defined medium must include a source of investigated for over 60 years. E.coli is a chemoheterotroph whose chemically defined medium must include a source of carbon and energy.