[Comparison of the in vitro activity of amoxycillin + clavulanic acid and ampicillin + sulbactam combinations against 50 Haemophilus influenzae strains producing beta lactamase].

We compared the ability of two beta lactamase inhibitors, clavulanic acid and sulbactam, to reduce the minimal inhibitory concentrations (MICs) respectively of amoxycillin and ampicillin against fifty strains of Haemophilus influenzae producing a beta lactamase. The reduction of MICs of aminopenicillins was studied using low concentrations of beta lactamase inhibitors (0.125 to 0.5 mg/l). Moreover, the synergic effect of each association was evaluated against a heavy bacterial inoculum (10(8) cfu/ml). The combination of amoxycillin + clavulanic acid was more synergic on these strains than the association of ampicillin + sulbactam.