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 Google Scholar
Google Scholar
Right arrow Articles by Welch, T. J.
Right arrow Articles by Crosa, J. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Welch, T. J.
Right arrow Articles by Crosa, J. H.

 Previous Article  |  Next Article 

Infection and Immunity, September 2005, p. 5864-5872, Vol. 73, No. 9
0019-9567/05/$08.00+0     doi:10.1128/IAI.73.9.5864-5872.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Novel Role of the Lipopolysaccharide O1 Side Chain in Ferric Siderophore Transport and Virulence of Vibrio anguillarum

Timothy J. Welch{dagger} and Jorge H. Crosa*

Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon 97201

Received 3 January 2005/ Returned for modification 24 February 2005/ Accepted 21 April 2005

From a library of approximately 20,000 transposon mutants, we have identified mutants affected in chromosomal genes involved in synthesis of the siderophore anguibactin, as well as in ferric anguibactin utilization. Genetic and sequence analyses of one such transport-defective mutant revealed that the transposon insertion occurred in an open reading frame (ORF) with homology to rmlC, a dTDP-rhamnose biosynthetic gene. This ORF resides within a cluster of four ORFs, all of which are predicted to function in the biosynthesis of this O side chain precursor. The same phenotype was seen in a mutant obtained by allelic exchange in rmlD, another ORF in this dTDP-rhamnose biosynthetic cluster. This mutation could be complemented with the wild-type rmlD gene, restoring both production of the O1 antigen side chain and ferric anguibactin transport. Presence of the O1 side chain was crucial for the resistance of Vibrio anguillarum to the bactericidal action of nonimmune serum from the fish host. Surprisingly, further analysis demonstrated that these mutations were pleiotropic, leading to a dramatic decrease in the levels of FatA, the outer membrane protein receptor for ferric anguibactin transport, and a concomitant reduction in iron transport. Thus, our results in this work demonstrate that the lipopolysaccharide O1 side chain is required for the operation of two critical virulence factors in V. anguillarum: serum resistance and anguibactin-mediated iron transport. These factors allow V. anguillarum to survive in serum and multiply in the iron-limiting milieu of the host vertebrate.

* Corresponding author. Mailing address: Department of Molecular Microbiology and Immunology, Oregon Health and Science University; 3181 Sam Jackson Park Road, Portland, OR 97239. Phone: (503) 494-7583. Fax: (503) 494-6862. E-mail: crosajor{at}ohsu.edu.

Editor: J. T. Barbieri

{dagger} Present address: National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, U.S. Department of Agriculture, Kearneysville, WV 25430.

Infection and Immunity, September 2005, p. 5864-5872, Vol. 73, No. 9
0019-9567/05/$08.00+0     doi:10.1128/IAI.73.9.5864-5872.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.





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