What is the treatment for native valve infective endocarditis caused by susceptible streptococci?

• A. Penicillin
• B. Gentamicin alone
• C. Ceftriaxone alone
• D. Vancomycin

Answer: (A)

Penicillin G is the best choice because susceptible streptococci respond rapidly to beta-lactam therapy, and penicillin provides reliable bactericidal activity against these organisms in native-valve endocarditis. It achieves effective concentrations in the bloodstream and within vegetations, leading to efficient sterilization of the infection. Gentamicin alone is not sufficient and adds toxicity risk, and vancomycin is reserved for penicillin allergies or resistant strains. Ceftriaxone can be an alternative in some cases, but when the organism is susceptible, penicillin remains the most proven, first-line option.