This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
A patyient needs antibiotic treatment for aificial valve, culture-positive infective enterococcal endocarditis. His medical history includes severe anaphylactic reaction to penbicillin G during the past year. The best approach would be treatment with: 
Select and explain. 
A. Amoxicillin-clavulanic acid, B. Aztreonam, C. Cefazolin plus gentamicin, D. Vancomycin
D: Vancomycin
Answer: D: Vancomycin 
Explanation: (Ref: KDT 6/e p732) Severe allergy to penicillins rule out the use of amoxicillin and cefazolin. Vancomycin is highly effective against MRSA and enterococcal infections. Drugs for VRSA and VRE (Vancomcin Resistant Enterococcus faecalis) include linezolid and daptomycin.