The Pel Polysaccharide Can Serve a Structural and Protective Role in the Biofilm Matrix of Pseudomonas aeruginosa

PLoS Pathogens

Gerard C. L. Wong¹  Daniel J. Wozniak²  Kelly M. Colvin³  Keiji Murakami³  Bradley R. Borlee³  Matthew R. Parsek³  Vernita D. Gordon⁴ 

[1] Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, United States of America;Department of Microbiology, Ohio State University, Columbus, Ohio, United States of America;Department of Microbiology, University of Washington, Seattle, Washington, United States of America;Department of Physics, University of Texas, Austin, Austin, Texas, United States of America

关键词: Biofilms;    Bacterial biofilms;    Antibiotics;    Polysaccharides;    Arabinose;    Biofilm culture;    Pseudomonas aeruginosa;    Extracellular matrix;   

DOI  :  10.1371/journal.ppat.1001264

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Bacterial extracellular polysaccharides are a key constituent of the extracellular matrix material of biofilms. Pseudomonas aeruginosa is a model organism for biofilm studies and produces three extracellular polysaccharides that have been implicated in biofilm development, alginate, Psl and Pel. Significant work has been conducted on the roles of alginate and Psl in biofilm development, however we know little regarding Pel. In this study, we demonstrate that Pel can serve two functions in biofilms. Using a novel assay involving optical tweezers, we demonstrate that Pel is crucial for maintaining cell-to-cell interactions in a PA14 biofilm, serving as a primary structural scaffold for the community. Deletion of pelB resulted in a severe biofilm deficiency. Interestingly, this effect is strain-specific. Loss of Pel production in the laboratory strain PAO1 resulted in no difference in attachment or biofilm development; instead Psl proved to be the primary structural polysaccharide for biofilm maturity. Furthermore, we demonstrate that Pel plays a second role by enhancing resistance to aminoglycoside antibiotics. This protection occurs only in biofilm populations. We show that expression of the pel gene cluster and PelF protein levels are enhanced during biofilm growth compared to liquid cultures. Thus, we propose that Pel is capable of playing both a structural and a protective role in P. aeruginosa biofilms.

【 授权许可】

CC BY