Fluoroquinolones is an antibiotic used especially in the treatment of systematic infections.Quinolones inhibit DNA gyrase and topoisomerase IVMECHANISM1.Inhibition of DNA Gyrase (Topoisomerase II):Fluoroquinolones bind to the DNA gyrase enzyme, which is responsible for introducing negative supercoils into the bacterial DNA.• By binding to DNA gyrase, fluoroquinolones prevent it from introducing negative supercoils into DNA.• This inhibition leads to the accumulation of positive supercoils ahead of the replication fork.2.Inhibition of Topoisomerase IV:Fluoroquinolones also inhibit topoisomerase IV, another enzyme involved in DNA replication.• Topoisomerase IV is responsible for separating the interlinked daughter chromosomes during DNA replication.• Inhibition of this enzyme leads to the accumulation of DNA breaks and prevents proper separation of daughter chromosomes.3.Disruption of DNA Replication and Repair:With both DNA gyrase and topoisomerase IV inhibited, DNA replication is disrupted.• Bacterial cells are unable to properly replicate their DNA and repair damaged DNA.•The accumulation of DNA damage and the inability to repair it eventually leads to bacterial cell death.4.Selective Action: fluoroquinolones exhibit a higher affinity for bacterial topoisomerases compared to mammalian topoisomerases, providing selective action against bacterial cells with minimal impact on human cells.