This Article Full Text (PDF) Other Versions of this Article: JB.01646-07v1 190/8/2709    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kintz, E. Articles by Goldberg, J. B. Search for Related Content PubMed PubMed Citation Articles by Kintz, E. Articles by Goldberg, J. B.

 Previous Article  |  Next Article 

J. Bacteriol. doi:10.1128/JB.01646-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Lipopolysaccharide O Antigen Chain Length Regulation in Pseudomonas aeruginosa Serogroup O11 Strain PA103

Department of Microbiology, University of Virginia Health System, Charlottesville, VA

^* To whom correspondence should be addressed. Email: jbg2b{at}virginia.edu.

	Abstract

The Wzz proteins are important for determining the length of the O antigen side chain attached to lipopolysaccharide (LPS). Several bacteria, including Pseudomonas aeruginosa strain PAO1 (serogroup O5), produce two such proteins responsible for the preference of two different chain lengths on the surface. Our group has previously identified one wzz gene (wzz1) within the O antigen locus of P. aeruginosa strain PA103 (serogroup O11). In this study we have identified the second wzz gene (wzz2) located in the same region of the genome and with 92% similarity to PAO1's wzz2 gene. Mutations were generated in both wzz genes by interruption with antibiotic resistance cassettes and the effects of these mutations were characterized. Wild-type PA103 prefers two O antigen chain lengths, referred to as long and very long. The expression of the long O antigen chain length was reduced in the wzz1 mutant, indicating the Wzz1 protein is important for this chain length preference. The wzz2 mutant, on the other hand, was missing O antigens of the very long chain length, indicating the Wzz2 protein is responsible for the production of very long O antigen. The effect of the wzz mutations on virulence was also investigated. In both serum sensitivity assays and a mouse pneumonia model of infection, the wzz1 mutants exhibited greater defects in virulence compared to either wild-type PA103 or the wzz2 mutant, indicating the long chain length plays a greater role during these infectious processes.