• genes
  • The control of DNA-supercoiling in S. pneumoniae occurs mainly via the regulation of topoisomerase gene transcription: relaxation triggers the up-regulation of gyrase and the down-regulation of topoisomerases I and IV, while hypernegative supercoiling down-regulates the expression of topoisomerase I. Relaxation affects 13% of the genome, with the majority of the genes affected located in 15 domains. (frontiersin.org)
  • 13, 14 In laboratory mutants of N gonorrhoeae , mutations in the gyr A and gyr B genes of DNA gyrase and in the par C gene of topoisomerase IV, associated with decreased susceptibilities to quinolones, have been identified. (bmj.com)
  • mutations
  • 16 Alterations in the ParC have been identified only in strains having GyrA mutations and had a complementary role in further decreasing susceptibility of N gonorrhoeae to fluoroquinolones. (bmj.com)
  • The presence of mutations in both gyrA and parC is strongly associated with reduced susceptibility to fluoroquinolones. (pubmedcentralcanada.ca)
  • fluorine
  • In particular, some congeners of this drug family (for example those that contain the C-8 fluorine), display high activity not only against bacterial topoisomerases, but also against eukaryotic topoisomerases and are toxic to cultured mammalian cells and in vivo tumor models. (wikipedia.org)
  • The majority of drugs in clinical use are actually quinoline derivatives that belong to the subset fluoroquinolones, which have a fluorine atom attached to the central ring system, often at the C-6 or C-7 position. (wikipedia.org)
  • Salmonella
  • Due to sickle-cell disease patients' being at increased risk for developing osteomyelitis from the Salmonella genus, fluoroquinolones are the "drugs of choice" due to their ability to enter bone tissue without chelating it, as tetracyclines are known to do. (wikipedia.org)
  • Escherichia
  • Aerobic Gram-positive microorganisms: Staphylococcus aureus (methicillin-susceptible strains) Streptococcus pneumoniae (penicillin-susceptible strains) Streptococcus pyogenes Aerobic Gram-negative microorganisms Citrobacter koseri (Citrobacter diversus) Enterobacter aerogenes Escherichia coli Haemophilus influenzae Klebsiella pneumoniae Neisseria gonorrhoeae Proteus mirabilis Pseudomonas aeruginosa Other microorganisms: Chlamydia trachomatis In general, fluoroquinolones are well tolerated, with most side-effects being mild to moderate. (wikipedia.org)
  • drugs
  • Even though this was the first fluoroquinolone, it is often overlooked when classifying the drugs within this class by generations and excluded from such a list. (wikipedia.org)
  • musculoskeletal
  • In most countries, fluoroquinolones are approved for use in children only under narrowly-defined circumstances, owing in part to the observation of high rates of musculoskeletal adverse events in fluoroquinolone treated juvenile animals. (wikipedia.org)
  • Fluoroquinolones are not licensed by the U.S. FDA for use in children due to the risk of permanent injury to the musculoskeletal system, with two exceptions. (wikipedia.org)
  • renal
  • In contrast to other fluoroquinolones, renal clearance accounts for only 5% of the removal of difloxacin from the canine system, which makes it an attractive choice for dogs with compromised renal function. (wikipedia.org)
  • molecules
  • The number of superhelical turns introduced into an initially relaxed circular DNA has been calculated to be approximately equal to the number of ATP molecules hydrolyzed by gyrase. (wikipedia.org)
  • Therefore, it can be suggested that two ATP molecules are hydrolyzed per cycle of reaction by gyrase, leading to the introduction of a linking difference of -2. (wikipedia.org)
  • Gyrase is present in prokaryotes and some eukaryotes, but the enzymes are not entirely similar in structure or sequence, and have different affinities for different molecules. (wikipedia.org)
  • tablets
  • The FDA wrote: "An FDA safety review has shown that fluoroquinolones when used systemically (i.e. tablets, capsules, and injectable) are associated with disabling and potentially permanent serious side effects that can occur together. (wikipedia.org)
  • Achilles
  • Tendinitis and rupture, usually of the Achilles tendon, are a class-effects of the fluoroquinolones, most frequently reported with pefloxacin. (wikipedia.org)
  • The most severe form of tendonopathy associated with fluoroquinolone administration is tendon rupture, which in the great majority of cases involves the Achilles tendon. (wikipedia.org)