Age-dependent changes in bacterial adherence to epithelial cells of nasopharynx in vivo

Epithelial cells were scraped from the posterior wall of the nasopharynx (NPH) of 20 consecutive patients (age range 1 to 52 years, 9 males, 11 females) undergoing ENT surgery under general anaesthesia. The cellular mixture was immediately homogenized, filtrated through a 5 microns pore filters and centrifuged (10 min, 1,500 rpm). Non-ciliated, squamous epithelial cells caught by the filter were harvested and stained with acridine orange. Epithelial cells with bacteria attached were evaluated when specimens were examined under a fluorescence microscope. A distinct difference was noted between young individuals and adult patients regarding bacterial adherence to nasopharyngeal epithelial cells, adherence in young patients being especially remarkable. Bacteria appeared not to attach to ciliated epithelial cells. The high incidence of otitis media infections among young individuals may be due to the remarkable bacterial adherence to nasopharyngeal non-ciliated epithelial cells in this age group.