Nucleotide sequence and characterization of the Staphylococcus aureus norA gene, which confers resistance to quinolones.

摘要: The norA gene cloned from chromosomal DNA of quinolone-resistant Staphylococcus aureus TK2566 conferred relatively high resistance to hydrophilic quinolones such as norfloxacin, enoxacin, ofloxacin, and ciprofloxacin, but only low or no at all hydrophobic ones nalidixic acid, oxolinic sparfloxacin in S. Escherichia coli. 2.7-kb fragment containing the had a long open reading frame coding for 388 amino acid residues with molecular weight 42,265, which was consistent experimental value about 49,000 obtained on DNA-directed translation. deduced NorA polypeptide has 12 membrane-spanning regions is partly homologous tetracycline protein sugar transport proteins. uptake quinolone, by harboring plasmid carrying 50% that parent strain lacking plasmid, it increased almost same level latter carbonyl cyanide m-chlorophenyl hydrazone. On other hand, sparfloxacin, similar two strains. These results suggest may constitute membrane-associated active efflux pump quinolones.