上気道細菌感染症における扁桃常在菌叢の意義

Abstract

Bacterial interference between normal oral flora and pathogens is known to play a significant role in non-specific host defense mechanisms against bacterial infection. In particular, much attension has been focused on a-streptococci with inhibitory activity against group A streptococcus in the oral cavity and throat.We developed a new method named “filter paper stamp method” to investigate the bacterial interference and this method was found to be simpler and more accurate than previous procedures. The detection rate of a-streptococci with inhibitory activity against group A streptococcus was examined in both healthy individuals and patients with tonsillitis. In healthy individuals, the inhibitory strains increased with age and may reflect the fact that group A streptococcal infection decrease with age. In patients with tonsillitis, the detection rate of inhibitory α-streptococcus in patients for whom tonsillectomy was clinically indicated was much lower than in those not indicated for this surgery. In the patients who received tonsillectomy, the detection rate of the inhibitory strains steadily increased after surgery. It is suggested that studies of α-streptococcus with inhibitory activity against group A streptococcus in the oral cavity and throat are of clinical significance in determining the indication for tonsillectomy and in evaluating the effect of surgery.We also found that non-pathogenic oral bacteria such as β-lactamase-producing H. parainfluenzae as well as α-streptococci with inhibitory activity against group A streptococcus were of considerable significance in the antimicrobial therapy for tonsillar infection. As a result, bacteriological follow-up studies of both pathogenic and non-pathogenic strains in the oral cavity and throat are of importance in patients with tonsillitis.