The incidence and antibiotic susceptibility of Branhamella catarrhalis in respiratory infections.

The incidence of Branhamella catarrhalis in respiratory infections at City Hospital, Edinburgh from January 1981 to April 1984 is described. Beginning in January 1982 there was an increased incidence associated with a high proportion of beta-lactamase-producing strains. The number of these strains increased: from January 1981 to April 1983, 61% of strains produced beta-lactamase, and 83% produced beta-lactamase from January to April 1984. 53% of patients were infected in hospital. Environmental studies showed that 7% of staff and 8% of patients were carriers; there was also circumstantial evidence of ward and patient-to-patient infection. The antimicrobial susceptibility of 54 clinical strains was tested: all strains were resistant to trimethoprim but were susceptible to clavulanic acid plus amoxycillin, chloramphenicol, erythromycin, co-trimoxazole, cefotaxime and cefuroxime. beta-Lactamase-negative strains were uniformly susceptible to penicillin and ampicillin.