Chronic secretory otitis media: negative bacteriology

There is disagreement on the role of bacteria in the genesis and maintenance of chronic secretory otitis media (CSOM). Extensive studies from other countries report up to 40% of middle ear cultures with bacterial growth. For the present study, material was collected from 94 ears of children with both clinical and tympanometric diagnoses of CSOM. The samples were sent for bacteriological analysis, in there it was stained according to Gram's method and put into growing media: MacConkey (for gram-negative bacteria) and blood agar (for gram-positive bacteria) for 24 h, at 37 degrees C. If germs were identified by Gram's method, antibiograms would be carried out as well, with the Mueller Hington medium. No cultures were made for anaerobes. Only one ear had grown bacteria (Staphylococcus epidermidis), which was deemed contamination. No other ear studied bore bacteria. The possible causes for this disagreement between our study and the literature are discussed.