Strain of Escherichia coli O157:H7

Although most kinds of E. coli bacteria do not cause disease in humans, those that are pathogenic are a significant threat to public health, especially relating to food safety.

The most common and notorious of these pathogenic bacteria are E. coli O17:H7, which part of a category call enterohemorrhagic E. coli (EHEC).

Escherichia coli O157:H7 was first identified as a human pathogenic in 1982. A rare but dangerous type of E. coli, the strain O157:H7 is now a major public health problem worldwide.

The main method of identifying pathogenic strains of E coli has been stereotyping base on specific markers found on the bacterial cell surface, namely the O, H and K antigens. The “O” antigen of E. coliO157:H7 was the 157th cell surface lipopolysaccharide or somatic antigen, to be identified; the ”H” antigen was the seven flagellar antigen identified.

The major reservoir of E. coli O157:H7 are ruminant animal, particularly cattle. E. coli O157:H7 has also been isolate from sheep, deer, and goats. E. O157:H7 was identified as the cause of two outbreaks of hemorrhagic colitis that occurred in 1982 and were associated with undercooked ground beef.
Strain of Escherichia coli O157:H7