Clinical significance of respiratory infection caused by Branhamella catarrhalis with special reference to beta-lactamase producing strains.

I found the recent increase during the past eight years of the incidence of respiratory infections caused by Branhamella catarrhalis. Namely, I experienced 74 cases (93 episodes) of the respiratory infections; 5 pneumonia, 14 acute bronchitis, 1 lung abscess, 36 chronic bronchitis, 7 chronic bronchiolitis, 21 bronchiectasis and 9 chronic pulmonary emphysema with infection. In 65 of 93 infectious episodes, Branhamella catarrhalis was isolated as a pure culture and in 28 episodes it was associated with other organisms, 13 Haemophilus influenzae etc. In all the cases, a positive correlation was found between beneficial clinical results and disappearance of the organism from the sputum. Minimum inhibitory concentrations of the representative beta-lactam and other antibiotics against 104 strains were determined. All of these strains were obtained during last four years from 1980 to 1983 from the purulent sputa as the main pathogen. Annually, this organism has significantly acquired resistance to beta-lactams. By 1983, 74% of Branhamella catarrhalis isolated from the purulent sputa became a beta-lactamase producers. And the failure cases of Branhamella catarrhalis infections treated with beta-lactams have increased during the last two years. These results have clearly showed also the importance of Branhamella catarrhalis as the common pathogen for respiratory organ.