Microbial dynamics of persistent purulent otitis media in children.

Repeated aspirations (for a period of 36 to 55 days) of the exudate through an open perforation were performed in seven children with acute otitis media that did not respond to antimicrobial therapy. Penicillin-resistant organisms were present in all but one of the first two aspirates. Failure to respond to antimicrobial therapy was associated with the emergence of resistant anaerobic and aerobic bacteria in the third and fourth cultures. The infection was cured in all instances after administration of antimicrobial agents effective against these bacteria.