Penicillin-Streptomycin Treatment of Enterococcal Endocarditis

ENTEROCOCCI (Streptococcus faecalis) are generally not highly sensitive to penicillin, and penicillin alone can rarely kill enterococcal populations. Although enterococci are generally resistant to streptomycin, the addition of that drug to penicillin frequently enhances its bactericidal activity in vitro. The combined antibacterial action of the two agents on enterococci is perhaps the most widely accepted example of antibiotic synergism. Their simultaneous administration has resulted in bacteriologic cures of enterococcal endocarditis in a large majority of cases.1 2 3 4 In our laboratory, studies on combined antibiotic effects have been pursued intermittently for the past fifteen years. Several questions have been raised. First of . . .