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 the causative agent -: (A) 0 157 : H7, (B) 0 159 : H7, (C) 0 107 : H7, (D) 0 55
Answer is A. Ans. is 'a' i.e., 0157 : 117