Antimicrobial treatment of anaerobic infections

Anaerobes are the most predominant components of normal human skin and mucous membrane bacterial flora and are, therefore, a common cause of endogenous bacterial infections. Because of their fastidious nature, they are difficult to isolate from infectious sites and are often overlooked. Anaerobic infections can occur at all body sites, including the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin and soft tissues.

This up-to-date review describes the antimicrobials available for the treatment of anaerobic infections and the advantages in using them according to the site of infection and expected antimicrobial susceptibility.

Treatment of anaerobic infection is complicated by the slow growth of these organisms, their polymicrobial nature and the growing resistance of anaerobes to antimicrobials. Antimicrobial therapy is often the only therapy required, or it is an important adjunct to a surgical approach. Because anaerobes generally are recovered mixed with aerobic organisms, the choice of appropriate antimicrobial should provide adequate coverage of both types of pathogen. The most effective antimicrobials against anaerobes are: metronidazole, the carbapenems, chloramphenicol, the combinations of a penicillin and a beta-lactamase inhibitor, and tigecycline.