Some kinds of E. coli cause disease by making a toxin called Shiga toxin. The bacteria that make these toxins are called Shiga-Toxin-producing E. coli or STEC. You might also hear them called verocytotoxic E. coli (VTEC) or enterohemorrhagic E. coli (EHEC); these all refer generally to the same group of bacteria. STEC cause the illness, hemorrhagic colitis, an intestinal illness that usually manifests as bloody diarrhea. The most commonly identified STEC in North America is E. coli O157:H7 (often shortened to E. coli O157 or even just “O157”). When you hear news reports about outbreaks of E. coli, they are usually talking about E. coli O157. E. coli O157:H7 has been closely linked to the illness hemolytic uremic syndrome (HUS), a rare blood disease that is the leading cause of acute kidney failure for children in the U.S.
In addition to E. coli O157, many other serogroups of STEC cause disease. These other kinds are sometimes called “non-O157 STEC.” E. coli serogroups O26, O111, and O103 are the non-O157 serogroups that most often cause illness in people in the United States.
Richard J. Arsenault, 2010
