Final answer:
An antibiotic that covers gram-negative bacilli should be prescribed for a patient with acute prostatitis, as most infections are caused by gram-negative bacteria like E. coli and Klebsiella pneumoniae.
Step-by-step explanation:
The clinician should prescribe an antibiotic that covers gram-negative bacilli for a patient with acute prostatitis. Most cases of prostatitis are caused by gram-negative bacteria, such as Escherichia coli (E. coli), Proteus vulgaris, Pseudomonas aeruginosa, and Klebsiella pneumoniae. These pathogens commonly cause urinary tract infections (UTIs) and can lead to prostatitis. Given this information, antibiotics effective against these gram-negative organisms would be the appropriate choice.