Comparison of the microbiology of group A and non-group A streptococcal tonsillitis.

We studied the microbial flora of tonsils removed from 20 children who suffered from recurrent group A beta-hemolytic streptococcal (GABHS) tonsillitis and 20 who had tonsillar hypertrophy following recurrent non-GABHS tonsillitis. Similar polymicrobial aerobic and anaerobic flora were recovered from the cores of the tonsils in each group. beta-Lactamase-producing bacteria (BLPB) were recovered more often in the group with GABHS. This difference was due mostly to the lower incidence of beta-lactamase-producing strains of Branhamella catarrhalis and Bacteroides sp in hypertrophic tonsils following non-GABHS tonsillitis. beta-Lactamase-producing Staphylococcus aureus was found with equal frequency in both groups. These findings demonstrate that although BLPB are recovered more often in recurrently inflamed tonsils following GABHS infection, BLPB also can be found in hypertrophic tonsils following non-GABHS tonsillitis.