In 1885, Theodor Escherich, a German pediatrician, first discovered Escherichia and Salmonella in the feces of healthy individuals and called it Bacterium coli commune.
E. Coli captured with the MW5-CCD camera on a BA310 biological microscope.
E. Coli cells are typically rod-shaped and are about 2 micrometers (um) long and 0.5um in diameter. Optimal growth of E. Coli occurs at 98.6°F (37°C), but some laboratory strains can multiply at temperatures up to 120°F (49°C).
E. Coli normally colonizes an infant's gastrointestinal tract within 40 hours of birth, arriving with food or water or with the individuals handling the child. In the bowel, it adheres to the mucus of the large intestine. As long as these bacteria do not acquire genetic elements encoding for virulence factors, they remain benign organisms that neither benefit, nor harm the other.