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: Medicine
All are true about primary bacterial peritonitis, EXCEPT: 
Select and explain. 
A. Ascitic fluid PMN count > 250 is diagnostic, B. Microbiology of PBP is distinctive, C. Some patients may be totally asymptomatic, D. Usually does not respond to routine antimicrobial therapy
D: Usually does not respond to routine antimicrobial therapy
Answer: D: Usually does not respond to routine antimicrobial therapy 
Explanation: PBP is commonly present with fever, but it can present without any symptoms too. Ascitic fluid analysis should be performed in all suspected cases and PMN > 250/l is diagnostic of PBP. Escherichia coli are most commonly encountered as the cause of PBP. In PBP, a single organism is typically isolated. PBP is usually treated with cefotaxime and it responds very well to it. Ref: Harrison, E-18, P-1081.