[In vitro effect of cefixime against Haemophilus influenzae]

Cefixime activity has been determined against Haemophilus influenzae strains producing or not beta-lactamase, or resistant to ampicillin by non-enzymatic mechanism. All strains are inhibited by a concentration of 1 mg/l of cefixime independently of beta-lactamase secretion. Ampicillin-resistant non beta-lactamase producing strains are inhibited by concentrations of 0.12 - 1 mg/l. MIC50 and MIC90 were, respectively, 0.06 and 0.12 mg/l for ampicillin-susceptible strains and 0.12 and 0.12 mg/l for ampicillin-resistant strains. The activity of cefixime against Haemophilus influenzae was superior to that of other orally administered antibiotics tested in this study: amoxicillin, amoxicillin-clavulanic acid, cefaclor and cefuroxime.