Microorganisms in chronic otitis media with effusion.

A total of 175 effusions obtained from 172 patients suffering from chronic otitis media with effusions was examined for bacterial smear and culture. Eighty percent showed positive bacterial smear, but only 49% yielded positive bacterial culture. The mucoid effusions had positive cultures in only 37%, whereas the bacterial culture rate was higher in serous (59%) and leukocytic (64%) types. The isolation of common pathogens accounted for about 50% of the isolates, and nonpathogens accounted for the remaining 50%. The high incidence of microorganisms in the middle ear effusions in the present series raises the possibility of bacterial contribution in many cases of OME.