Effect of amoxycillin with or without clavulanate on adenoid bacterial flora

The effect of antimicrobial therapy with amoxycillin (AMX) or co-amoxiclav (AMC) on the adenoid bacterial flora of 45 children with recurrent otitis media (ROM), scheduled for elective adenoidectomy, was studied. Patients were randomized before surgery into three groups of 15, having had either no antibiotic therapy (control), or 10 days of therapy with AMX or AMC. Core adenoid tissues were quantitatively cultured for aerobic and anaerobic bacteria. Polymicrobial aerobic-anaerobic flora was present in all instances. The predominant aerobes in all groups were alpha-haemolytic and non-haemolytic streptococci, Haemophilus influenzae, Staphylococcus aureus, group A beta-haemolytic streptococci and Moraxella catarrhalis. The prominent anaerobes were Peptostreptococcus spp., Prevotella spp. and Fusobacterium spp. The number of isolates was significantly reduced in those treated with AMX (110; P < 0.05) or AMC (54; P < 0.001) compared with control (148). The number of bacteria per gram of tissue was lower in those treated with both antibiotics. The number of potential pathogens was lower in those treated with AMC compared with the other two groups (P < 0.001 ). The number of beta-lactamase- producing bacteria (BLPB) was lower in those treated with AMC compared with those treated with AMX (P < 0.025) or no antibiotic (P < 0.001). These data illustrate the ability of AMX and AMC to reduce the bacterial load as well as potential pathogens and BLPB from the adenoids of children with ROM.