The role of coagulase-negative staphylococci in chronic otitis media with effusion

Twenty-eight middle ear effusions from 27 patients with chronic otitis media with effusion were studied for the presence of bacteria. The most common isolates were coagulase-negative staphylococci. However, biochemical and antibiotic sensitivity patterns demonstrated that these organisms represented a heterogenous group. At least three subtypes of coagulase-negative staphylococci were identified from the middle ear effusions, and in only one instance was the isolate from the ear canal identical with that of the middle ear effusion. The data presented suggest that coagulase-negative staphylococci from the middle ear effusions may not be contaminants; however, it cannot be determined from this study whether these organisms play a role as pathogens or as the result of indolent colonization.