Escherichia coli O121 is a serotype of Escherichia coli, a species of bacteria that lives in the lower intestines of mammals.
Escherichia coli | 1993 Jack in the Box E. coli outbreak | Verotoxin-producing Escherichia coli | Melanosis coli | ''Escherichia coli'' O157:H7 | enteroaggregative ''E. coli'' | ''E. coli'' bacteria |