Escherichia coli

Escherichia coli is a Gram-negative, facultative anaerobic, rod-shaped bacterium of the genus Escherichia. This is a large diverse group of bacteria which predominantly inhabit the gastrointestinal tract of mammals and are shed to the environment through feces. Most pathogenic E. coli are transmitted by fecal-oral route from food materials, water, animals, and environment. Shedding of E. coli in feces makes this microorganism abundantly available in the environment.