This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Folster, J. P.
Right arrow Articles by Shafer, W. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Folster, J. P.
Right arrow Articles by Shafer, W. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, June 2005, p. 3713-3720, Vol. 187, No. 11
0021-9193/05/$08.00+0     doi:10.1128/JB.187.11.3713-3720.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Regulation of mtrF Expression in Neisseria gonorrhoeae and Its Role in High-Level Antimicrobial Resistance

Jason P. Folster1,2 and William M. Shafer1,2*

Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322,1 Laboratories of Microbial Pathogenesis, Veterans Affairs Medical Center, Decatur, Georgia 300332

Received 27 January 2005/ Accepted 2 March 2005

The obligate human pathogen Neisseria gonorrhoeae uses the MtrC-MtrD-MtrE efflux pump to resist structurally diverse hydrophobic antimicrobial agents (HAs), some of which bathe mucosal surfaces that become infected during transmission of gonococci. Constitutive high-level HA resistance occurs by the loss of a repressor (MtrR) that negatively controls transcription of the mtrCDE operon. This high-level HA resistance also requires the product of the mtrF gene, which is located downstream and transcriptionally divergent from mtrCDE. MtrF is a putative inner membrane protein, but its role in HA resistance mediated by the MtrC-MtrD-MtrE efflux pump remains to be determined. High-level HA resistance can also be mediated through an induction process that requires enhanced transcription of mtrCDE when gonococci are grown in the presence of a sublethal concentration of Triton X-100. We now report that inactivation of mtrF results in a significant reduction in the induction of HA resistance and that the expression of mtrF is enhanced when gonococci are grown under inducing conditions. However, no effect was observed on the induction of mtrCDE expression in an MtrF-negative strain. The expression of mtrF was repressed by MtrR, the major repressor of mtrCDE expression. In addition to MtrR, another repressor (MpeR) can downregulate the expression of mtrF. Repression of mtrF by MtrR and MpeR was additive, demonstrating that the repressive effects mediated by these regulators are independent processes.

* Corresponding author. Mailing address: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322. Phone: (404) 728-7688. Fax: (404) 329-2210. E-mail: wshafer{at}emory.edu.

Journal of Bacteriology, June 2005, p. 3713-3720, Vol. 187, No. 11
0021-9193/05/$08.00+0     doi:10.1128/JB.187.11.3713-3720.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Folster, J. P., Johnson, P. J. T., Jackson, L., Dhulipali, V., Dyer, D. W., Shafer, W. M. (2009). MtrR Modulates rpoH Expression and Levels of Antimicrobial Resistance in Neisseria gonorrhoeae. J. Bacteriol. 191: 287-297 [Abstract] [Full Text]  
  • Garvin, L. E., Bash, M. C., Keys, C., Warner, D. M., Ram, S., Shafer, W. M., Jerse, A. E. (2008). Phenotypic and Genotypic Analyses of Neisseria gonorrhoeae Isolates That Express Frequently Recovered PorB PIA Variable Region Types Suggest that Certain P1a Porin Sequences Confer a Selective Advantage for Urogenital Tract Infection. Infect. Immun. 76: 3700-3709 [Abstract] [Full Text]  
  • Folster, J. P., Dhulipala, V., Nicholas, R. A., Shafer, W. M. (2007). Differential Regulation of ponA and pilMNOPQ Expression by the MtrR Transcriptional Regulatory Protein in Neisseria gonorrhoeae. J. Bacteriol. 189: 4569-4577 [Abstract] [Full Text]  
  • Piddock, L. J. V. (2006). Clinically Relevant Chromosomally Encoded Multidrug Resistance Efflux Pumps in Bacteria. Clin. Microbiol. Rev. 19: 382-402 [Abstract] [Full Text]  
  • Shafer, W. M., Folster, J. P. (2006). Towards an Understanding of Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae: Evidence for a Porin-Efflux Pump Collaboration.. J. Bacteriol. 188: 2297-2299 [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»