Antibacterial activity of the sulbactam-ampicillin combination.

The in vitro antibacterial activity of ampicillin combined with sulbactam 2:1 was evaluated on 257 aerobic Gram-positive and Gram-negative bacteria, and on 174 anaerobic bacteria from isolated hospital strains by evaluating the minimum inhibitory concentration (MIC). The results obtained show a synergic effect which was able to significantly decrease the MIC90 of the tested beta-lactamase producing bacteria. Among the Gram-positive aerobic strains, we underline the efficacy of sulbactam/ampicillin on resistant Staphylococci, including those methicillin-resistant. The activity on the Gram-negative strains was particularly evident against enterobacteria and haemophilus. The combination of sulbactam and ampicillin provides increased activity against anaerobic strains, including Bacteroides fragilis.