title: Effects of norfloxacin on DNA metabolism in Pseudomonas aeruginosa.
abstract: Norfloxacin is a quinolone (pyridonecarboxylic acid derivative) effective against Pseudomonas aeruginosa infections. We studied the effects of this drug on DNA metabolism in P. aeruginosa. Norfloxacin inhibits DNA replication immediately on its addition to a logarithmically growing culture of P. aeruginosa. It inhibits the ability of P. aeruginosa DNA gyrase to supercoil relaxed, closed circular DNA in vitro. At intermediate concentrations of the drug, inhibition of DNA replication in vivo is followed by secondary (recovery) synthesis. Both recovery synthesis and the bactericidal effects of norfloxacin are dependent on continued protein synthesis, suggesting that these are inducible functions. Neither norfloxacin nor nalidixic acid induces Weigle-reactivation (inducible DNA repair) or mutagenesis in P. aeruginosa.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004269:DNA, Bacterial / Q000096:biosynthesis*; D009152:Mutagenicity Tests; D009643:Norfloxacin / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004250:DNA Topoisomerases, Type II; D009643:Norfloxacin