What is the common name for the bacterium Escherichia coli?

The common name for the bacterium Escherichia coli is E. coli. The shortened form combines the first letter of the genus, Escherichia, with the species name, coli. In formal scientific writing, the genus is capitalized, the species name is lowercase, and both are italicized: Escherichia coli. The abbreviation is written E. coli, with a period after the initial.

E. coli normally lives in the intestines of humans and many other warm-blooded animals. Most strains are harmless and form part of the usual gut microbial community. Scientists also use harmless laboratory strains extensively in genetics, molecular biology, and biotechnology because the organism grows quickly and is relatively easy to study.

The name is often associated with illness because some strains carry genes that produce toxins or otherwise enable infection. These pathogenic variants can cause food poisoning, diarrhea, urinary-tract infections, or more serious disease. E. coli is not the same as Salmonella, Shigella, or Vibrio; those are different bacterial genera, although they can cause some overlapping symptoms.