Effect of different combinations of sparfloxacin, oxacillin, and fosfomycin against methicillin-resistant staphylococci

The in vitro activity of combinations of sparfloxacin/oxacillin, sparfloxacin/fosfomycin, and oxacillin/fosfomycin was investigated against 16 methicillin-resistantStaphylococcus aureus (MRSA) isolates and 12 methicillin-resistantStaphylococcus epidermidis (MRSE) isolates moderately resistant to sparfloxacin. Synergic interactions were observed more frequently against MRSE than against MRSA strains. The most effective combination on both species was fosfomycin plus oxacillin, synergistic against ten of 16 MRSA and eight of 12 MRSE strains.