Esherichia coli (E.coli) O157:H7 is an enterohemorrhagic strain and a cause of foodborne illness. These Diarrheagenic E.coli are classi-fied into five types.
 Among these,  Enterohemorrhagic E.coli (EHEC) causes hemorrhagic colitis through the production of the verotoxin that it produces; it can also cause hemolytic uremic syndrome and encephalopathy, which can be fatal.

 Most illness has been associated with eating undercooked, contaminated beef, drinking unpasteurized milk, drinking contaminated water and contaminated vegetables.  The bacteria can also be spread by faces or polluted food. In addition to E. coli O157,  other verotoxin production strains have known detected, O26, O111, O118, O103, and O121 strain. In Japan, however, most of EHEC are reported to be of E.coli O157.

 Establishment of rapid  diagnostic method is important to perform appropriate treatment and measures, and prevent the spread of secondly infections.