Association between tonsillar core microflora and post-tonsillectomy bacteremia

Abstract

The aim of the study was to determine whether the population levels of aerobic and anaerobic bacteria in the core tonsils of adults with recurrent acute tonsillitis influence the development of post-tonsillectomy bacteremia. For that purpose we performed qualitative and quantitative bacteriology of 24 excised tonsillar core specimens, together with aerobic and anaerobic perioperative blood cultures. The blood cultures from ten non-surgical patients with recurrent acute tonsillitis served as controls to determine the occurrence of baseline bacteremia. Post-tonsillectomy bacteremia was found in nine (38%) patients. Isolated bacteria were α-hemolytic streptococci (n = 2), group C β-hemolytic streptococci (n = 2), group A β-hemolytic streptococcus (GAS) (n = 1), Peptostreptococcus sp. (n = 1), Bacteroides sp. (n = 1) and Prevotella sp. (n = 2). None of the blood cultures from the controls were positive. Mixed aerobic and anaerobic bacterial flora was found in the tonsil cores from both the patients with blood culture positive or negative results. All blood culture isolates were also recovered in the corresponding tonsillar core, except for the GAS. However, its presence was subsequently demonstrated by PCR. In further analysis, we found no correlation between the bacterial population levels and the development of post-tonsillectomy bacteremia. The absence of GAS growth from the core tonsil of a patient with GAS bacteremia also suggests that translocation of certain bacteria may occur in spite of low counts. In conclusion, the occurrence of post-tonsillectomy bacteremia is quite frequent in adults and the spectrum of invading agents is variable.