The role of anaerobic bacteria in recurrent episodes of sinusitis and tonsillitis.

Chronic and recurrent upper respiratory tract infections represent a significant clinical challenge. The causative organisms tend to be heterogeneous, involving both aerobes and gram-positive and gram-negative anaerobes. There is evidence that these mixed groups of bacteria interact synergistically, enhancing and prolonging the overall virulence of infection. The role of anaerobic bacteria, in particular their proposed ability to protect susceptible organisms by the production of beta-lactamases, has been the subject of intense speculation. The evidence of a significant role for anaerobic bacteria in recurrent episodes of tonsillitis and sinusitis is reviewed and the most appropriate antimicrobial strategies and possible future developments in diagnosis and therapy are discussed.