Chronic otitis media in children. Microbiological studies.

Aspiration of the exudate through the open perforation was performed in 68 children with chronic otitis media. The middle ear aspirate and a swab specimen of the external auditory canal were cultured aerobically and anaerobically. Seventy-eight isolates were recovered from the middle ears, 99 from the external ear canals, and 95 were present at both sites. Aerobes only were isolated from 33 patients (48.5%), nine (13.2%) had only anaerobes, and 26 (38%) had a culture that grew both aerobes and anaerobes. There were 99 aerobic isolates. Aerobes commonly recovered were Pseudomonas aeruginosa, Staphylococcus aureus, Proteus sp, Klebsiella pneumoniae, and Haemophilus influenzae. There were 74 anaerobes isolated. Anaerobes commonly isolated were anerobic Gram-positive cocci, Bacteroides sp, and Clostridium sp. These findings demonstrate the polymicrobial bacteriology of chronic otitis media in children. Cultures collected from the external auditory canals prior to their sterilization can be misleading. Reliable information can be obtained from the ear exudates when collected through the open perforation in the tympanic membrane.