Anaerobic bacteria in chronic otitis media.

Abstract

The bacteriology of 200 patients aged between 2 months to 80 years (mean 23 years) with chronic ear infections was studied. A total of 142 patients had otitis media with effusion, and 58 had chronic otitis media but no effusion. A total of 222 specimens were cultured. From the 142 patients with active disease, 16 specimens were taken from the mastoid antrums. Anaerobic bacteria were recovered from 10% of the draining ears; none occurred in the ears without effusion; and 17% of specimens from the infected mastoids grew anaerobic organisms. All of them were Bacteroides species. The antimicrobial susceptibility pattern of the isolates showed a 100% sensitivity of the Bacteroides isolates to metronidazole and chloramphenicol and a high level of resistance to commonly used systemic antibiotics. Fungal infection of the middle ear was found in 6.5% of the isolates.