[Studies on the combined effect of fosfomycin with sulbactam/cefoperazone on methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa].

We studied the combined effect of fosfomycin (FOM) with sulbactam/cefoperazone (SBT/CPZ) on clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA, 246 strains) and Pseudomonas aeruginosa (190 strains) in vitro. In ratio of mixed serum concentration of antibiotics at three hours after intravenous administration, the combination of FOM with SBT/CPZ and alone of arbekacin showed over 90% in cumulative percentage of MIC against MRSA and P. aeruginosa. The effect of the combination of FOM and SBT/CPZ was observed in MRSA strains of > 16 micrograms/ml of SBT/CPZ MIC and > 256 micrograms/ml FOM MIC. As well as in P. aeruginosa strains, the effect of the combination of FOM and SBT/CPZ was observed in strains of > 16 micrograms/ml of SBT/CPZ MIC and < 256 micrograms/ml FOM MIC, but it was not remarkable in strains of > 256 micrograms/ml FOM MIC. These results suggests that the combination treatment of FOM and SBT/CPZ may be effective for mixed infection of MRSA and P. aeruginosa.