<prompt> A 20 year old man presented with hemorrhagic colitis. The stool sample grew Escherichia coli in pure culture. The following serotype of E.coli is likely to be causative agent -0157:H70 159:H70107:H70 55:H7  <response>: Ans. is a i.e., 0 157 : H7 . Amongst E. coli, Enterohemorrhagic E. coli causes heamorrhagic colitis and the typical EHEC is serotype 0157: H7. Remember . Few other serotype such as 026 : Hl also belongs to this category. 