Surface vs core-tonsillar aerobic and anaerobic flora in recurrent tonsillitis

Specimens from both the surface and the core of tonsils from 23 children with recurrent tonsillitis were cultured for aerobic and anaerobic microorganisms. Mixed aerobic and anaerobic flora were obtained from all patients. The predominant anaerobic isolates were Bacteroides sp, Fusobacterium nucleatum, anaerobic Gram-positive cocci, and Eubacterium sp. The predominant aerobic isolates were alpha-hemolytic streptococci, Staphylococcus aureus, beta-hemolytic streptococci, and Haemophilus sp. beta-Lactamase production was noted in 49 isolates from 19 patients (83%). Seventy percent of the aerobic isolates were recovered in both core and surface specimens, compared with 57% of the anaerobic isolates. Ten percent of aerobes were recovered only in the core, compared with 33% of the anaerobes, and 20% of the aerobes in the surface only, compared wtih 10% of the anaerobes. These data demonstrate the discrepancies between surface and core cultures in the isolation of anaerobic bacteria, and raise the question whether surface cultures can accurately predict the presence of beta-lactamase-producing organisms or other pathogens in the recurrently infected tonsil.