Clinical and bacteriological evaluation of Branhamella catarrhalis in respiratory infections.

The clinical significance of Branhamella catarrhalis in respiratory infections is evaluated. 175 strains were isolated, mainly from the sputum, in 71 patients with respiratory infections. B. catarrhalis was most frequently isolated in mixed infections with Haemophilus influenzae (38.3%), H. influenzae plus Streptococcus pneumoniae (10.3%) or S. pneumoniae (9.7%). The rate of isolation of B. catarrhalis alone was as low as 5.1% and from mixed infections with Pseudomonas aeruginosa, Escherichia coli, and Enterobacter and/or Klebsiella species it was 36.6%. More than 10(7) cfu/ml of B. catarrhalis were isolated from 71.4% of cases. In 29 cases the organism was determined to be causative according to our criteria, most often in secondary infections in patients with complicated pneumoconiosis, chronic bronchitis and bronchiectasis. 29 of 47 strains (61.7%) produced beta-lactamase of the penicillinase type. Against these strains, penicillin antibiotics and first and second generation cephalosporin antibiotics (except cefroxadine) showed weak activity compared with their activity against non-beta-lactamase-producing strains. The third generation cephalosporins showed a uniform spectrum of activity against both groups of organisms.