Aerobic and anaerobic bacteriology of cholesteatoma.

Cholesteatoma specimens were obtained from 28 patients undergoing surgery for chronic otitis media and cholesteatoma. All specimens were cultured for aerobic and anaerobic organisms. Bacterial growth was present in specimens of 24 of the 28 patients. A total of 74 bacterial isolates were present (40 aerobes and 34 anaerobes). Aerobes alone were isolated from 8 (33%) of culture positive patients, 4 patients (26.7%) yielded only anaerobes, and 12 (50%) had both aerobic and anaerobic bacteria. Fifty isolates (27 aerobes and 23 aerobes) were present in a concentration greater than 10(6) CFU/gm. The most commonly isolated aerobic organisms were P. aeruginosa (9), Proteus sp. (7), K. pneumoniae (5), S. aureus (5), and E. coli (4). The anaerobic bacteria most commonly isolated were gram-positive anaerobic cocci (12), Bacteroides sp. (12, including 5 B. fragilis group), Clostridium sp. (3), and Bifidobacterium sp. (3). The above findings indicate the polymicrobial aerobic and anaerobic bacteriology of cholesteatoma.