Abstract
The in vitro sensitivity of 108 strains of Neisseria catarrhalis to ampicillin, penicillin G, penicillin V, erythromycin and oxytetracycline was determined. The strains were isolated, inter alia, from ear exudate of children with acute otitis media. Ampicillin was more active than penicillin G, which was followed by erythromycin, penicillin V and oxytetracycline. In acute otitis media caused by N. catarrhalis, an effect could probably be expected of ampicillin and of penicillin V treatment with daily dosages of 50 mg per kg body weight. Erythromycin would be preferred to oxytetracycline in those instances in which penicillins are contraindicated.