In acute suppurative otitis media, Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes are the most commonly isolated pathogens.1.2 These bacteria are susceptible to many antibiotic agents used in general practice and thus empirical therapy with antibiotics directed against these pathogens is usually successful.
Since 1971 we have seen eight pediatric patients with acute otitis media and mastoiditis from whom the initial microbiological isolates were Pseudomonas aeruginosa and indole-positive Proteus strains. These Gram-negative bacilli, while frequently present in chronic otitis media3 and external malignant otitis, generally have not been considered to be etiologically important in acute otitis media.4.5 We present these patients to emphasize that failure to appreciate the pathogenic role of P aeruginosa in acute suppurative otitis media leads to irreparable delay in initiating adequate therapy and an unusually high rate of mastoiditis.
Patients and Methods.—During the period of 1971 to 1976, eight pediatric patients