Figure 2.
Mechanisms of metronidazole resistance. Metronidazole (MTZ) acts by inducing DNA strand breakage and cytotoxicity, causing bacterial cell death.31 It is administered as an inactive prodrug that is activated under reductive conditions inside the cell.31C. difficile (CD) resistance to MTZ may be achieved by factors that prevent the generation of the active form of the drug, which are possibly mediated by multigenetic mechanisms involved in oxidoreductive and iron-dependent metabolic pathways.32–34 While the high copy number plasmid pCD-METRO is associated with CD MTZ resistance, its mechanism is unknown.11 CD growing in biofilms have shown increased tolerance to MTZ.40 *, mutated. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.