In vitro susceptibilities and β-lactamase production of 53 clinical isolates of Branhamella catarrhalis

We tested 53 clinical isolates of Branhamella catarrhalis recovered from patients with respiratory symptoms to determine the susceptibility of the isolates to 25 antimicrobial agents, including the newer β-lactam antibiotics. Of the 53 strains, 46 (86.7%) were β-lactamase producers. All the strains were susceptible to the majority of the new penicillins and cephalosporins. The combinations of amoxacillin-clavulanic acid and ticarcillin-clavulanic acid were also very active against the β-lactamase-producing strains.