Escherichia coli

Theodor Escherich, a German bacteriologist reported the isolation of a bacterium called Bacteria coli from a fecal sample in 1885. Later in 1888, it was renamed Escherichia coli. E. coli is a Gram-negative, shortrods (1-2μm in length), aerobic, and generally motile organism. Some pathogenic strains are also acid resistant. A majority of E. coli strains are nonpathogenic and exist harmlessly in the intestinal tract of humans and animals. E. coli has been used extensively as a model organism to study bacterial physiology, metabolism, genetic regulation, signal transduction, and cell wall structure and function. Pathogenic E. coli strains cause a variety of diseases including gastroenteritis, dysentery, hemolytic uremic syndrome (HUS), urinary tract infection (UTI), septicemia, pneumonia, and meningitis. However, the major concern in recent years has been the increasing numbers of outbreaks of enterohemorrhagic E. coli, due to consumption of contaminated meat, fruits, and vegetables primarily in developing countries.