Metronidazole versus anaerobes. In vitro data and initial clinical observations.

Metronidazole, a systemic trichomonicide which has been used extensively since 1960, has recently been shown to be active against various anaerobic bacteria in vitro and in experimental infections. In the present study, metronidazole showed significant activity against virtually all of 54 strains of anaerobic and microaerophilic bacteria tested, including Bacteroides fragilis. Since this organism is the anaerobe most commonly isolated from human infections and has demonstrated significant resistance to many antimicrobial agents, metronidazole may prove to be very useful. Our initial clinical evaluation of metronidazole in human anaerobic infections is presented. Because of metronidazole's in vitro activity, its low incidence of toxic reactions, and this initial favorable clinical trial, the drug deserves further evaluation in the management of anaerobic infections.