A male patient, aged , presents to the emergency department complaining of a -day history of fever, chills, and severe left knee swelling. He has a past medical history significant for type diabetes mellitus but denies any recent falls or joint trauma. Initial vital signs reveal a temperature of (), blood pressure of , and heart rate of . Physical examination highlights a warm, intensely erythematous, and exquisitely tender left knee with a noticeable effusion.
Arthrocentesis is performed, yielding frankly purulent synovial fluid with a leukocyte count of ( neutrophils). Blood and synovial fluid cultures are obtained, and he is empirically started on intravenous vancomycin and ceftriaxone before undergoing urgent arthroscopic lavage.
On hospital day , the patient demonstrates clinical improvement and is currently afebrile. The microbiology laboratory reports that both the synovial fluid and blood cultures are growing *Staphylococcus aureus*. Susceptibility testing demonstrates that the isolate is resistant to penicillin but susceptible to oxacillin, cefazolin, and clindamycin. The patient's allergy profile notes a mild, non-pruritic maculopapular rash that occurred after taking amoxicillin during childhood; he has never experienced anaphylaxis, angioedema, or respiratory compromise associated with any medication.
Which of the following is the most appropriate antimicrobial regimen for this patient going forward?
- Intravenous cefazolinCevap
- BIntravenous vancomycin
- CIntravenous daptomycin
- DIntravenous piperacillin-tazobactam
- EOral cephalexin