E. coli O157:H7 is one of hundreds of strains of
the bacterium Escherichia coli. Although most strains are harmless
and live in the intestines of healthy humans and animals, this strain
produces a powerful toxin and can cause severe illness. E. coli O157:H7 was first recognized as a cause of
illness in 1982 during an outbreak of severe bloody diarrhea; the
outbreak was traced to contaminated hamburgers. Since then, most
infections have come from eating undercooked ground beef. The combination of letters and numbers in the name
of the bacterium refers to the specific markers found on its surface
and distinguishes it from other types of E. coli. from
CDC |
