This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'An elderly male develops fever 3 days after cholecystectomy. He becomes sho of breath, andCXR shows a new right lower lobe infiltrate. Sputum Gram stain shows gram-positive cocci in clumps, and preliminary culture results suggest staphylococci. Initial antibiotic of choice is \nSelect and explain. \nA. Nafcillin, B. Vancomycin, C. Antibiotic therapy should be based on the incidence of methicillin-resistant staphylococci in that hospital, D. Quinolones is the drug of choice for pneumonia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In the treatment of hospital acquired staphylococcal pneumonia, the incidence of methicillin-resistant staph in the local facility will be very impoant. In most hospitals, methicillin-resistant staph is common enough to require initial therapy with vancomycin. Oxacillin would be the drug of choice only if the incidence of methicillin-resistant staph is very low. Quinolones are often useful in the treatment of community-acquired pneumonia, but they would not be effective against methicillin-resistant staph.', 'role': 'assistant'}]