Present addresses: Robert P. Ryan, BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
An acquired efflux system is responsible for copper resistance in Xanthomonas strain IG-8 isolated from China
Article first published online: 11 JAN 2007
FEMS Microbiology Letters
Volume 268, Issue 1, pages 40–46, March 2007
How to Cite
Ryan, R. P., Ryan, D. J., Sun, Y.-C., Li, F.-M., Wang, Y. and Dowling, D. N. (2007), An acquired efflux system is responsible for copper resistance in Xanthomonas strain IG-8 isolated from China. FEMS Microbiology Letters, 268: 40–46. doi: 10.1111/j.1574-6968.2006.00592.x
Yi-Cheng Sun, Department of Microbiology, University of Alabama at Birmingham, USA.
Editor: Skorn Mongkolsuk
- Issue published online: 15 JAN 2007
- Article first published online: 11 JAN 2007
- Received 5 July 2006; revised 6 November 2006; accepted 9 November 2006.First published online 11 January 2007.
- antimicrobial resistance;
- solvent tolerance;
- efflux pumps;
- horizontal gene transfer
The genus Xanthomonas contains plant pathogens exhibiting innate resistance to a range of antimicrobial agents. In other genera, multidrug resistance is mediated by a synergy between a low-permeability outer membrane and expression of a number of multidrug efflux systems. This report describes the isolation of a novel gene cluster xmeRSA from Xanthomonas strain IG-8 that mediates copper chloride resistance. Subsequent analysis of these genes showed that they were responsible for the high level of multiple resistance in this strain and were homologues of the sme system of Stenotrophomonas maltophilia. Knock-out mutants of this gene cluster indicate that these genes are required for the copper resistance phenotype of strain IG-8. Expression analysis using lacZ fusions indicates that the genes are regulated by copper and other antimicrobials. Bioinformatic analysis suggests that these genes were acquired by horizontal gene transfer.