Metronidazole and drug resistance.

In recent years, the basis of metronidozole resistance has been examined in anaerobic protozoa, such as Trichomonas and Giardia, as well as anaerobic bacteria, such as Bacteroides and Clostridium. In this review, Patricia Johnson looks at a variety of mechanisms that lead to reduced susceptibility of these pathogens to the drug. The frequent correlation between metronidozole resistance and inefficient drug activation suggests that this is the level at which drug resistance operates.