Microbial and protozoal DNA and macromolecules

Microbial and protozoal DNA and macromolecules in anaerobic cells represent the primary pharmacological targets for the nitroimidazole class of anti-infective agents, such as metronidazole (StatPearls, NBK539728). These targets are specifically vulnerable in anaerobic environments where the low oxidation-reduction potential allows for the reductive activation of prodrugs. Upon entering the anaerobic cell, the drug is reduced by electron transport proteins such as ferredoxin, which are part of the pyruvate:ferredoxin oxidoreductase (PFOR) system (PubChem, CID 4168). This reduction produces short-lived, highly reactive nitro radical intermediates that form covalent bonds with DNA and other cellular macromolecules. The resulting damage includes DNA strand breakage, loss of helical structure, and inhibition of nucleic acid synthesis, ultimately leading to the death of the pathogen (DrugBank, DB00916). This mechanism provides high selectivity for anaerobic bacteria and certain protozoa, as aerobic cells lack the necessary reductive environment to activate the drugs.

Other names

Bacterial DNAProtozoal DNAAnaerobic cellular macromoleculesMicrobial nucleic acids

Reductive activation by anaerobic metabolic pathways (e.g., pyruvate:ferredoxin oxidoreductase) leads to the formation of reactive nitro radicals that cause DNA strand breakage and inhibition of nucleic acid synthesis.