The bacterial flora of the nasopharynx, with special reference to middle ear pathogens. A quantitative study in twenty children.

Quantification of middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis) and potential pathogens (S. aureus and coagulase-negative staphylococci) adhering to the posterior wall of the nasopharynx was performed in 20 patients of whom 5 were suffering from secretory otitis media (SOM), 5 from recurrent attacks of acute otitis media (rAOM), 5 from attacks of upper respiratory infection (URI) and 5 from blocked nose (BN). While the patients were under general anesthesia a glass cylinder (diameter 1.3 cm) was pressed against the posterior wall of the nasopharynx and swabs were taken from the mucosa delineated by the glass tube. Quantification of the bacteria was performed using blood and chocolate agar plates. Total bacterial counts ranged between 2.6 x 10(4)CFU/cm2 and 4.0 x 10(8)CFU/cm2. In the rAOM group, 4 out of 5 children had bacterial counts in the nasopharynx which constituted of 95% pathogens. Coagulase-negative staphylococci never exceeded 1.9 x 10(5)CFU/cm2.