Effects of antimicrobial therapy on the microbial flora of the adenoids.

The core of the adenoids contains polymicrobial aerobic and anaerobic flora and also includes potential respiratory pathogens. Similar flora, although in higher numbers and with a higher frequency of pathogens, are found in inflamed or hypertrophic adenoids and many of these bacteria are resistant to antimicrobial agents. Exposure to antimicrobial therapy can alter the colonization patterns and select for resistant organisms. Production of beta-lactamase is one of the major mechanisms of resistance of these organisms. The adenoids of healthy individuals, in contrast to those with recurrent respiratory tract infections, are generally colonized by aerobic and anaerobic organisms that are capable of interfering with the growth of potential pathogens. Maintaining the beneficial effects of normal flora by avoiding unnecessary exposure to antimicrobial therapy may be a useful tool in preventing colonization of the adenoids by potential pathogens. This review discusses the unique microbiology of the adenoids in individuals with a variety of pathological conditions, the interactions between the various organisms and the effects of antimicrobial therapy on the microbial flora of the adenoids.