Escherichia coli (E. coli) are members of a large group of bacterial germs that inhabit the intestinal tract of humans and other warm-blooded animals (mammals, birds). Newborns have a sterile alimentary tract, which within two days becomes colonized with E. coli.
More than 700 serotypes of E. coli have been identified. E. coli O157:H7, far and away the most notorious serotypes, is one of many shiga-toxin producing strain of the bug. Shiga toxin is one of the most potent toxins known to man, so much so that the Centers for Disease Control and Prevention (CDC) lists it as a potential bioterrorist agent. It seems likely that DNA from Shiga toxin-producing Shigella bacteria was transferred by a bacteriophage (a virus that infects bacteria) to otherwise harmless E. coli bacteria, thereby providing them with the genetic material to produce Shiga toxin.
Post-diarrheal hemolytic uremic syndrome (D+HUS) is a severe, life-threatening complication that occurs in about 10 percent of those infected with E. coli O157:H7 or other Shiga toxin- (Stx-) producing E. coli. D+HUS was first described in 1955, but was not known to be secondary to E. coli infections until 1982. It is now recognized as the most common cause of acute kidney failure in infants and young children. Adolescents and adults are also susceptible, as are the elderly, who often succumb to the disease. Read more on HUS, including its symptoms, diagnosis, and treatment.