Effect of amoxicillin or clindamycin on the adenoids bacterial flora.

Abstract

We sought to compare the effect on the adenoid bacterial flora of patients with recurrent otitis media of antimicrobial therapy with amoxicillin (Am) or clindamycin (C). Patients and methods Forty-five children scheduled for elective adenoidectomy participated in a prospective randomized study. They were divided into 3 groups of 15 each to receive either no therapy (control) or 10 days of therapy with Am or C. Core adenoid tissues was quantitatively cultured for aerobic and anaerobic bacteria. Polymicrobial aerobic-anaerobic flora were present in all instances. The predominant aerobes in all groups were alpha-hemolytic and gamma-hemolytic streptococci, Haemophilus influenzae, Staphylococcus aureus, group A beta-hemolytic streptococci, and Moraxella catarrhalis. The prominent anaerobes were Peptostreptococcus, Prevotella, and Fusobacterium spp. The number of isolates was significantly reduced in those treated with Am (n = 110, P < 0.05) or C (n = 58, P < 0.001) compared with control (n = 148). The number of bacteria per gram/tissue was lower in those treated with either antibiotics. The number of potential pathogens was lower in those treated with C compared with the other 2 groups (P < 0.001). The number of beta-lactamase-producing bacteria was lower in those treated with C than in those treated with Am (P < 0.025) or control (P < 0.001). These data illustrate the ability of C and, to a lesser degree, of Am to reduce the bacterial load as well as potential pathogens and beta-lactamase-producing bacteria from the adenoids of children with recurrent otitis media.