1995 Volume 69 Issue 9 Pages 982-986
The role of normal pharyngeal flora in the defense mechanism against infections in the upper respiratory tract was studied in 50 children with otitis media with effusion (O. M. E.).
In the bacteriological study of the nasopharynx, the incidence of H. influenzae, S. pneumoniae, S. aureus, M. catarrhalis and group A Streptococcus was about 46%, 24%, 20%, 12% and 8%, respectively. The incidence of these species in the cases with O. M. E. was higher than that in the cases with chronic tonsillitis or control cases.
In 41 O. M. E. cases with a-streptococci (82%), the incidence of α-streptococci with inhibitory activity against 5 pathogens (H. influenzae, S. pneumoniae, S. aureus, M. catarrhalis, group A Streptococcus) was examined. The detection rate of a-streptococcal strains with inhibitory activity against 5 pathogens derived from the nasopharynx in the cases with O. M. E. was significantly lower than that of the strain in the chronic tonsillitis cases and the control cases.
Moreover, the detection rate of inhibitory α-streptococci from the nasopharynx was lower than that of from the tonsil. These findings suggest that the decline of inhibitory activity against pathogens by normal flora in nasopharynx is one of the factors causing O. M. E.
