ANAEROBES IN POLYMICROBIAL SURGICAL INFECTIONS - INCIDENCE, PATHOGENICITY, AND ANTIMICROBIAL RESISTANCE

Many types of anaerobic bacteria have been isolated from clinical infe ctions. Although most of these infections are polymicrobial and involv e facultative Gram-negative bacilli, some are strictly anaerobic. For most of them, surgical intervention such as drainage of an abscess and debridement of devitalised tissue is the primary treatment and re-est ablishes good blood flow to the affected area. Appropriate antimicrobi al treatment is also important to kill both residual organisms and tho se that may have spread from the site of primary infection. Several gr oups of anaerobes (for example, Bacteroides fragilis group, Prevotella , Porphyromonas, and Fusobacterium) have developed mechanisms of resis tance to beta-lactam agents, the most common of which is production of beta-lactamases. A recent approach to neutralising these enzymes has been to combine the beta-lactam agent with an irreversible beta-lactam ase inhibitor. Because of their potency against both aerobes and anaer obes, these combinations may replace traditional combination treatment (gentamicin/ clindamycin) for polymicrobial infections. Piperacillin/ tazobactam was the beta-lactam/beta-lactamase combination that was mos t active against the B fragilis group in the present study.