Skip Navigation



JAC Advance Access published online on October 9, 2006
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkl407
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
58/6/1250    most recent
dkl407v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
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 Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Bratu, S.
Right arrow Articles by Quale, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bratu, S.
Right arrow Articles by Quale, J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org
Received June 30, 2006
Revised September 6, 2006
Accepted September 12, 2006

Brief report

Expression of the las and rhl quorum-sensing systems in clinical isolates of Pseudomonas aeruginosa does not correlate with efflux pump expression or antimicrobial resistance

Simona Bratu 1, Jyoti Gupta 1, and John Quale 1 *

1 Division of Infectious Diseases, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA

* To whom correspondence should be addressed.
John Quale, E-mail: jquale{at}downstate.edu


  Abstract

Objectives: Quorum-sensing systems regulate expression of several virulence factors and may affect the MexAB-OprM efflux system in Pseudomonas aeruginosa. This study investigated the relationship between two quorum-sensing systems, efflux pump MexAB-OprM expression and antimicrobial resistance in 33 clinical isolates of P. aeruginosa.

Methods: Expression of the quorum-sensing regulatory genes lasR and rhlR was assessed by real time RT-PCR. The autoinducer synthetase genes lasI and rhlI and the regulatory genes mexT and mexS were characterized by DNA sequencing. Production of pyocyanin and elastase in each of the isolates was also determined.

Results: While there was a significant correlation between expression of the quorum-sensing regulatory genes and production of pyocyanin and elastase, there was no correlation with expression of mexA or with antimicrobial resistance. There were no mutations in lasI, rhlI, mexT or mexS that correlated with quorum-sensing expression.

Conclusions: Increased activity of two quorum-sensing systems in P. aeruginosa does not contribute to increased mexA expression or antimicrobial resistance.

Keywords: virulence mechanisms; resistance mechanisms; {beta}-lactamase.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Antimicrob. Agents Chemother.Home page
J. B. Bulitta, N. S. Ly, J. C. Yang, A. Forrest, W. J. Jusko, and B. T. Tsuji
Development and Qualification of a Pharmacodynamic Model for the Pronounced Inoculum Effect of Ceftazidime against Pseudomonas aeruginosa
Antimicrob. Agents Chemother., January 1, 2009; 53(1): 46 - 56.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.