1887

Abstract

Biocides and dyes are commonly employed in hospital and laboratory settings. Many of these agents are substrates for multiple-drug resistance (MDR)-conferring efflux pumps of both Gram-positive and Gram-negative organisms. Several such pumps have been identified in , and mutants overexpressing the NorA and MepA MDR pumps following exposure to fluoroquinolones have been identified. The effect of exposure to low concentrations of biocides and dyes on the expression of specific pump genes has not been evaluated. Using quantitative reverse-transcription PCR we found that exposure of clinical isolates to low concentrations of a variety of biocides and dyes in a single step, or to gradually increasing concentrations over several days, resulted in the appearance of mutants overexpressing , , and , with overexpression predominating. Overexpression was frequently associated with promoter-region or regulatory protein mutations. Mutants having significant increases in MICs of common pump substrates but no changes in expression of studied pump genes were also observed; in these cases changes in expression of as-yet-unidentified MDR pump genes may have occurred. Strains of that exist in relatively protected environments and are repeatedly exposed to sublethal concentrations of biocides can develop efflux-related resistance to those agents, and acquisition of such strains poses a threat to patients treated with antimicrobial agents that are also substrates for those pumps, such as ciprofloxacin and moxifloxacin.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.2008/021188-0
2008-10-01
2019-11-19
Loading full text...

Full text loading...

/deliver/fulltext/micro/154/10/3144.html?itemId=/content/journal/micro/10.1099/mic.0.2008/021188-0&mimeType=html&fmt=ahah

References

  1. Ausubel, F. M., Brent, R., Kingston, R. E., Moore, D. D., Seidman, J. G., Smith, J. A. & Struhl, K. ( 2005; ). Current Protocols in Molecular Biology. New York: Wiley.
  2. Bateman, B. T., Donegan, N. P., Jarry, T. M., Palma, M. & Cheung, A. L. ( 2001; ). Evaluation of a tetracycline-inducible promoter in Staphylococcus aureus in vitro and in vivo and its application in demonstrating the role of sigB in microcolony formation. Infect Immun 69, 7851–7857.[CrossRef]
    [Google Scholar]
  3. Boyce, J. M. ( 2007; ). Environmental contamination makes an important contribution to hospital infection. J Hosp Infect 65 (Suppl. 2), 50–54.[CrossRef]
    [Google Scholar]
  4. Bryson, V. & Szybalski, W. ( 1952; ). Microbial selection. Science 115, 45–51.
    [Google Scholar]
  5. CLSI ( 2006; ). Approved standard M7-A7. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically, 7th edn. Wayne, PA: Clinical and Laboratory Standards Institute.
  6. DeMarco, C. E., Cushing, L. A., Frempong-Manso, E., Seo, S. M., Jaravaza, T. A. & Kaatz, G. W. ( 2007; ). Efflux-related resistance to norfloxacin, dyes, and biocides in bloodstream isolates of Staphylococcus aureus. Antimicrob Agents Chemother 51, 3235–3239.[CrossRef]
    [Google Scholar]
  7. Hassan, K. A., Skurray, R. A. & Brown, M. H. ( 2007; ). Active export proteins mediating drug resistance in staphylococci. J Mol Microbiol Biotechnol 12, 180–196.[CrossRef]
    [Google Scholar]
  8. Horobin, R. W. & Kiernan, J. A. ( 2002; ). Conn's Biological Stains, 10th edn. Oxford, UK: BIOS Scientific Publishers.
  9. Horsburgh, M. J., Aish, J. L., White, I. J., Shaw, L., Lithgow, J. K. & Foster, S. J. ( 2002; ). σ B modulates virulence determinant expression and stress resistance: characterization of a functional rsbU strain derived from Staphylococcus aureus 8325-4. J Bacteriol 184, 5457–5467.[CrossRef]
    [Google Scholar]
  10. Huang, J., O'Toole, P. W., Shen, W., Amrine-Madsen, H., Jiang, X., Lobo, N., Palmer, L. M., Voelker, L., Fan, F. & other authors ( 2004; ). Novel chromosomally encoded multidrug efflux transporter MdeA in Staphylococcus aureus. Antimicrob Agents Chemother 48, 909–917.[CrossRef]
    [Google Scholar]
  11. Kaatz, G. W. ( 2005; ). Bacterial efflux pump inhibition. Curr Opin Investig Drugs 6, 191–198.
    [Google Scholar]
  12. Kaatz, G. W. & Seo, S. M. ( 1995; ). Inducible NorA-mediated multidrug resistance in Staphylococcus aureus. Antimicrob Agents Chemother 39, 2650–2655.[CrossRef]
    [Google Scholar]
  13. Kaatz, G. W., Seo, S. M., O'Brien, L., Wahiduzzaman, M. & Foster, T. J. ( 2000; ). Evidence for the existence of a multidrug efflux transporter distinct from NorA in Staphylococcus aureus. Antimicrob Agents Chemother 44, 1404–1406.[CrossRef]
    [Google Scholar]
  14. Kaatz, G. W., McAleese, F. & Seo, S. M. ( 2005a; ). Multidrug resistance in Staphylococcus aureus due to overexpression of a novel multidrug and toxin extrusion (MATE) transport protein. Antimicrob Agents Chemother 49, 1857–1864.[CrossRef]
    [Google Scholar]
  15. Kaatz, G. W., Thyagarajan, R. V. & Seo, S. M. ( 2005b; ). Effect of promoter region mutations and mgrA overexpression on transcription of norA, which encodes a Staphylococcus aureus multidrug efflux transporter. Antimicrob Agents Chemother 49, 161–169.[CrossRef]
    [Google Scholar]
  16. Kaatz, G. W., DeMarco, C. E. & Seo, S. M. ( 2006; ). MepR, a repressor of the Staphylococcus aureus MATE family multidrug efflux pump MepA, is a substrate-responsive regulatory protein. Antimicrob Agents Chemother 50, 1276–1281.[CrossRef]
    [Google Scholar]
  17. Levy, S. B. ( 2002; ). Active efflux, a common mechanism for biocide and antibiotic resistance. J Appl Microbiol 92 (Suppl.), 65S–71S.[CrossRef]
    [Google Scholar]
  18. Livak, K. J. & Schmittgen, T. D. ( 2001; ). Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔ C (T) method. Methods 25, 402–408.[CrossRef]
    [Google Scholar]
  19. Luong, T. T., Dunman, P. M., Murphy, E., Projan, S. J. & Lee, C. Y. ( 2006; ). Transcription profiling of the mgrA regulon in Staphylococcus aureus. J Bacteriol 188, 1899–1910.[CrossRef]
    [Google Scholar]
  20. Markham, P. N. & Neyfakh, A. A. ( 1996; ). Inhibition of the multidrug transporter NorA prevents emergence of norfloxacin resistance in Staphylococcus aureus. Antimicrob Agents Chemother 40, 2673–2674.
    [Google Scholar]
  21. McBain, A. J., Rickard, A. H. & Gilbert, P. ( 2002; ). Possible implications of biocide accumulation in the environment on the prevalence of bacterial antibiotic resistance. J Ind Microbiol Biotechnol 29, 326–330.[CrossRef]
    [Google Scholar]
  22. McDonnell, G. & Russell, A. D. ( 1999; ). Antiseptics and disinfectants: activity, action, and resistance. Clin Microbiol Rev 12, 147–179.
    [Google Scholar]
  23. McMurry, L. M., Oethinger, M. & Levy, S. B. ( 1998; ). Overexpression of marA, soxS, or acrAB produces resistance to triclosan in laboratory and clinical strains of Escherichia coli. FEMS Microbiol Lett 166, 305–309.[CrossRef]
    [Google Scholar]
  24. Moken, M. C., McMurry, L. M. & Levy, S. B. ( 1997; ). Selection of multiple-antibiotic-resistant (Mar) mutants of Escherichia coli by using the disinfectant pine oil: roles of the mar and acrAB loci. Antimicrob Agents Chemother 41, 2770–2772.
    [Google Scholar]
  25. Narui, K., Noguchi, N., Wakasugi, K. & Sasatsu, M. ( 2002; ). Cloning and characterization of a novel chromosomal drug efflux gene in Staphylococcus aureus. Biol Pharm Bull 25, 1533–1536.[CrossRef]
    [Google Scholar]
  26. Paulsen, I. T., Brown, M. H., Littlejohn, T. G., Mitchell, B. A. & Skurray, R. A. ( 1996a; ). Multidrug resistance proteins QacA and QacB from Staphylococcus aureus: membrane topology and identification of residues involved in substrate specificity. Proc Natl Acad Sci U S A 93, 3630–3635.[CrossRef]
    [Google Scholar]
  27. Paulsen, I. T., Brown, M. H. & Skurray, R. A. ( 1996b; ). Proton-dependent multidrug efflux systems. Microbiol Rev 60, 575–608.
    [Google Scholar]
  28. Poole, K. ( 2005; ). Efflux-mediated antimicrobial resistance. J Antimicrob Chemother 56, 20–51.[CrossRef]
    [Google Scholar]
  29. Russell, A. D. ( 2003; ). Biocide use and antibiotic resistance: the relevance of laboratory findings to clinical and environmental situations. Lancet Infect Dis 3, 794–803.[CrossRef]
    [Google Scholar]
  30. Sanger, F., Nicklen, S. & Coulson, A. R. ( 1977; ). DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A 74, 5463–5467.[CrossRef]
    [Google Scholar]
  31. Sapunaric, F. M. & Levy, S. B. ( 2005; ). Substitutions in the interdomain loop of the Tn10 TetA efflux transporter alter tetracycline resistance and substrate specificity. Microbiology 151, 2315–2322.[CrossRef]
    [Google Scholar]
  32. Smith, K., Gemmell, C. G. & Hunter, I. S. ( 2008; ). The association between biocide tolerance and the presence or absence of qac genes among hospital-acquired and community-acquired MRSA isolates. J Antimicrob Chemother 61, 78–84.
    [Google Scholar]
  33. Szoke, P. A., Allen, T. L. & deHaseth, P. L. ( 1987; ). Promoter recognition by Escherichia coli RNA polymerase: effects of base substitutions in the −10 and −35 regions. Biochemistry 26, 6188–6194.[CrossRef]
    [Google Scholar]
  34. Truong-Bolduc, Q. C., Dunman, P. M., Strahilevitz, J., Projan, S. J. & Hooper, D. C. ( 2005; ). MgrA is a multiple regulator of two new efflux pumps in Staphylococcus aureus. J Bacteriol 187, 2395–2405.[CrossRef]
    [Google Scholar]
  35. Truong-Bolduc, Q. C., Strahilevitz, J. & Hooper, D. C. ( 2006; ). NorC, a new efflux pump regulated by MgrA of Staphylococcus aureus. Antimicrob Agents Chemother 50, 1104–1107.[CrossRef]
    [Google Scholar]
  36. Yamada, Y., Hideka, K., Shiota, S., Kuroda, T. & Tsuchiya, T. ( 2006; ). Gene cloning and characterization of SdrM, a chromosomally-encoded multidrug efflux pump, from Staphylococcus aureus. Biol Pharm Bull 29, 554–556.[CrossRef]
    [Google Scholar]
  37. Yamaguchi, A., Nakatani, M. & Sawai, T. ( 1992; ). Aspartic acid-66 is the only essential negatively charged residue in the putative hydrophilic loop region of the metal-tetracycline/H+ antiporter encoded by transposon Tn10 of Escherichia coli. Biochemistry 31, 8344–8348.[CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.2008/021188-0
Loading
/content/journal/micro/10.1099/mic.0.2008/021188-0
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error