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. 1995 Dec;39(12):2650–2655. doi: 10.1128/aac.39.12.2650

Inducible NorA-mediated multidrug resistance in Staphylococcus aureus.

G W Kaatz 1, S M Seo 1
PMCID: PMC163006  PMID: 8592996

Abstract

The NorA protein of Staphylococcus aureus mediates the active efflux of hydrophilic fluoroquinolones from the cell, conferring low-level resistance upon the organism. The protein also is capable of transporting additional structurally diverse compounds, indicating that it has a broad substrate specificity. Increased transcription of the norA gene, leading to a greater quantity of the NorA protein within the cytoplasmic membrane, is felt to be the mechanism by which strains possessing such changes resist fluoroquinolones. S. aureus SA-1199 and its in vivo-selected derivative SA-1199B are fluoroquinolone-susceptible and -resistant isolates, respectively; SA-1199B resists hydrophilic fluoroquinolones via a NorA-mediated mediated mechanism in a constitutive manner. SA-1199-3 is an in vitro-produced derivative of SA-1199 in which NorA-mediated multidrug resistance is expressed inducibly. Compared with organisms exposed to subinhibitory concentrations of a NorA substrate for the first time, preexposure of SA-1199-3 to such a compound followed by growth in the presence of that substrate results in the elimination of a 2- to 6-h period of organism killing that occurs prior to the onset of logarithmic growth. The uptake of radiolabeled fluoroquinolone is markedly reduced by preexposure of SA-1199-3 to NorA substrates: such prior exposure also results in a dramatic increase in RNa transcripts that hybridize with a norA probe. Preexposure of SA-1199 and SA-1199B to such substrates results in small increases or no increases in these transcripts. No sequence differences between SA-1199 and SA-1199-3 within the norA gene or flanking DNA were found. It appears likely that the regulation of norA in SA-1193, which may be effected by one or more genetic loci outside the norA region of the chromosome, differs from that of SA-1199 and SA-1199B.

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Selected References

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  1. Ahmed M., Borsch C. M., Neyfakh A. A., Schuldiner S. Mutants of the Bacillus subtilis multidrug transporter Bmr with altered sensitivity to the antihypertensive alkaloid reserpine. J Biol Chem. 1993 May 25;268(15):11086–11089. [PubMed] [Google Scholar]
  2. Chomczynski P. A reagent for the single-step simultaneous isolation of RNA, DNA and proteins from cell and tissue samples. Biotechniques. 1993 Sep;15(3):532-4, 536-7. [PubMed] [Google Scholar]
  3. Ferrero L., Cameron B., Manse B., Lagneaux D., Crouzet J., Famechon A., Blanche F. Cloning and primary structure of Staphylococcus aureus DNA topoisomerase IV: a primary target of fluoroquinolones. Mol Microbiol. 1994 Aug;13(4):641–653. doi: 10.1111/j.1365-2958.1994.tb00458.x. [DOI] [PubMed] [Google Scholar]
  4. Goswitz J. J., Willard K. E., Fasching C. E., Peterson L. R. Detection of gyrA gene mutations associated with ciprofloxacin resistance in methicillin-resistant Staphylococcus aureus: analysis by polymerase chain reaction and automated direct DNA sequencing. Antimicrob Agents Chemother. 1992 May;36(5):1166–1169. doi: 10.1128/aac.36.5.1166. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Harnett N., Brown S., Krishnan C. Emergence of quinolone resistance among clinical isolates of methicillin-resistant Staphylococcus aureus in Ontario, Canada. Antimicrob Agents Chemother. 1991 Sep;35(9):1911–1913. doi: 10.1128/aac.35.9.1911. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Hooper D. C., Wolfson J. S. Mode of action of the new quinolones: new data. Eur J Clin Microbiol Infect Dis. 1991 Apr;10(4):223–231. doi: 10.1007/BF01966994. [DOI] [PubMed] [Google Scholar]
  7. Kaatz G. W., Seo S. M., Ruble C. A. Efflux-mediated fluoroquinolone resistance in Staphylococcus aureus. Antimicrob Agents Chemother. 1993 May;37(5):1086–1094. doi: 10.1128/aac.37.5.1086. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kaatz G. W., Seo S. M., Ruble C. A. Mechanisms of fluoroquinolone resistance in Staphylococcus aureus. J Infect Dis. 1991 May;163(5):1080–1086. doi: 10.1093/infdis/163.5.1080. [DOI] [PubMed] [Google Scholar]
  9. Lindberg M., Sjöström J. E., Johansson T. Transformation of chromosomal and plasmid characters in Staphylococcus aureus. J Bacteriol. 1972 Feb;109(2):844–847. doi: 10.1128/jb.109.2.844-847.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Neyfakh A. A., Bidnenko V. E., Chen L. B. Efflux-mediated multidrug resistance in Bacillus subtilis: similarities and dissimilarities with the mammalian system. Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4781–4785. doi: 10.1073/pnas.88.11.4781. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Neyfakh A. A., Borsch C. M., Kaatz G. W. Fluoroquinolone resistance protein NorA of Staphylococcus aureus is a multidrug efflux transporter. Antimicrob Agents Chemother. 1993 Jan;37(1):128–129. doi: 10.1128/aac.37.1.128. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Neyfakh A. A. The multidrug efflux transporter of Bacillus subtilis is a structural and functional homolog of the Staphylococcus NorA protein. Antimicrob Agents Chemother. 1992 Feb;36(2):484–485. doi: 10.1128/aac.36.2.484. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ng E. Y., Trucksis M., Hooper D. C. Quinolone resistance mediated by norA: physiologic characterization and relationship to flqB, a quinolone resistance locus on the Staphylococcus aureus chromosome. Antimicrob Agents Chemother. 1994 Jun;38(6):1345–1355. doi: 10.1128/aac.38.6.1345. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Novick R. P. Genetic systems in staphylococci. Methods Enzymol. 1991;204:587–636. doi: 10.1016/0076-6879(91)04029-n. [DOI] [PubMed] [Google Scholar]
  15. Pearce H. L., Winter M. A., Beck W. T. Structural characteristics of compounds that modulate P-glycoprotein-associated multidrug resistance. Adv Enzyme Regul. 1990;30:357–373. doi: 10.1016/0065-2571(90)90026-x. [DOI] [PubMed] [Google Scholar]
  16. Peterson L. R., Quick J. N., Jensen B., Homann S., Johnson S., Tenquist J., Shanholtzer C., Petzel R. A., Sinn L., Gerding D. N. Emergence of ciprofloxacin resistance in nosocomial methicillin-resistant Staphylococcus aureus isolates. Resistance during ciprofloxacin plus rifampin therapy for methicillin-resistant S aureus colonization. Arch Intern Med. 1990 Oct;150(10):2151–2155. [PubMed] [Google Scholar]
  17. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Shalit I., Berger S. A., Gorea A., Frimerman H. Widespread quinolone resistance among methicillin-resistant Staphylococcus aureus isolates in a general hospital. Antimicrob Agents Chemother. 1989 Apr;33(4):593–594. doi: 10.1128/aac.33.4.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Silver S., Budd K., Leahy K. M., Shaw W. V., Hammond D., Novick R. P., Willsky G. R., Malamy M. H., Rosenberg H. Inducible plasmid-determined resistance to arsenate, arsenite, and antimony (III) in escherichia coli and Staphylococcus aureus. J Bacteriol. 1981 Jun;146(3):983–996. doi: 10.1128/jb.146.3.983-996.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Southern E. M. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. doi: 10.1016/s0022-2836(75)80083-0. [DOI] [PubMed] [Google Scholar]
  21. Sreedharan S., Oram M., Jensen B., Peterson L. R., Fisher L. M. DNA gyrase gyrA mutations in ciprofloxacin-resistant strains of Staphylococcus aureus: close similarity with quinolone resistance mutations in Escherichia coli. J Bacteriol. 1990 Dec;172(12):7260–7262. doi: 10.1128/jb.172.12.7260-7262.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Trucksis M., Wolfson J. S., Hooper D. C. A novel locus conferring fluoroquinolone resistance in Staphylococcus aureus. J Bacteriol. 1991 Sep;173(18):5854–5860. doi: 10.1128/jb.173.18.5854-5860.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Yoshida H., Bogaki M., Nakamura S., Ubukata K., Konno M. Nucleotide sequence and characterization of the Staphylococcus aureus norA gene, which confers resistance to quinolones. J Bacteriol. 1990 Dec;172(12):6942–6949. doi: 10.1128/jb.172.12.6942-6949.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]

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