Bacterial and protozoal deoxyribonucleic acid (DNA)

Bacterial and protozoal deoxyribonucleic acid (DNA) in anaerobic organisms serves as the primary molecular target for the nitroimidazole class of antibiotics, such as metronidazole (StatPearls, 2023). These drugs function as prodrugs that require reductive activation within the low-redox environment characteristic of anaerobic metabolism. Specifically, electron transport proteins like ferredoxin or flavodoxin transfer electrons to the nitro group of the drug, generating highly reactive nitro radical anions (PubChem, 2024). These radicals cause extensive oxidative damage to the microbial DNA, including the loss of helical structure and the induction of single- and double-strand breaks (Löfmark et al., 2010). This catastrophic damage inhibits DNA synthesis and transcription, leading to rapid cell death in susceptible pathogens. The selectivity of this mechanism is due to the absence of these high-energy reductive pathways in aerobic cells, which prevents the formation of toxic intermediates in the host (PubMed, 2022).

Other names

Microbial DNAAnaerobic genomic DNAProkaryotic DNABacterial DNAProtozoal DNA

Nitroimidazole drugs act as prodrugs that undergo reductive activation by the pyruvate:ferredoxin oxidoreductase (PFOR) system in anaerobic organisms. This reduction generates reactive nitro radical intermediates that cause oxidative damage to the DNA, resulting in strand breakage, loss of helical structure, and inhibition of nucleic acid synthesis (StatPearls, 2023; PubChem, 2024).