Experimental endocarditis caused by Streptococcus sanguis: single and combined antibiotic therapy.

The effectiveness of penicillin G, fosfomycin, and cefoxitin alone and in combination was studied in vitro and in the treatment of left-sided Streptococcus sanguis endocarditis in rabbits. In vitro, the combinations penicillin G plus fosfomycin, penicillin G plus cefoxitin, and fosfomycin plus cefoxitin were synergistic or partially synergistic for S sanguis. Therapy with the combinations was more effective in eradicating the species from cardiac vegetations that was that with each antibiotic used alone.