This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
[{'content': 'E. coli can be classified by their characteristic virulence propeies and different mechanisms that cause disease. To which group does the verotoxin producing E. coli 0157:H7 serotype belong? \nSelect and explain. \nA. Enteroaggregative E. coli (EAEC), B. Enterohemorrhagic E. coli (EHEC), C. Enteroinvasive E. coli (EIEC), D. Enteropathogenic E. coli (EPEC)', 'role': 'user'}, {'content': 'Answer: B \nExplanation: E. coli 0157:H7 serotype belongs to EHEC. EHEC Highly virulent serotype. Has low infectious dose (10-100 bacilli). Produce a verotoxin similar to Shiga toxin. Causes hemorrhagic colitis, HUS. Principal cause of acute kidney failure in children.', 'role': 'assistant'}]