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 HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Crawford, R. W.
Right arrow Articles by Gunn, J. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Crawford, R. W.
Right arrow Articles by Gunn, J. S.

 Previous Article  |  Next Article 

Infection and Immunity, November 2008, p. 5341-5349, Vol. 76, No. 11
0019-9567/08/$08.00+0     doi:10.1128/IAI.00786-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Identification of a Bile-Induced Exopolysaccharide Required for Salmonella Biofilm Formation on Gallstone Surfaces{triangledown}

Robert W. Crawford,1 Deanna L. Gibson,2,3 William W. Kay,3 and John S. Gunn1*

Center for Microbial Interface Biology and Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio 43210,1 Division of Gastroenterology, University of British Columbia and BC Children's Hospital, Vancouver, British Columbia, Canada,2 Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada3

Received 23 June 2008/ Returned for modification 28 July 2008/ Accepted 4 September 2008

Salmonella enterica serovar Typhi can establish a chronic, asymptomatic infection of the human gallbladder, suggesting that this bacterium utilizes novel mechanisms to mediate enhanced colonization and persistence in a bile-rich environment. Gallstones are one of the most important risk factors for developing carriage, and we have previously demonstrated that salmonellae form biofilms on human gallstones in vitro. Thus, we hypothesize that bile-induced biofilms on gallstone surfaces promote gallbladder colonization and maintenance of the carrier state. A colanic acid/cellulose S. enterica serovar Typhimurium double mutant formed a mature biofilm on gallstones in a test tube assay and in a new, gallstone-independent assay using cholesterol-coated Eppendorf tubes. These data suggest the presence of an unidentified exopolysaccharide necessary for mature biofilm development and demonstrate specific binding affinity between salmonellae and cholesterol. Our experiments indicate that the Salmonella O-antigen capsule (yihU-yshA and yihV-yihW) is a crucial determinant in gallstone and cholesterol biofilms but that expression of this exopolysaccharide is not necessary for binding to glass or plastic. Real-time PCR revealed that growth in bile resulted in upregulation of the O-antigen capsule-encoding operon in an agfD-independent manner. Thus, the O-antigen capsule genes are bile induced, and the capsule produced by the enzymes of this operon is specifically required for biofilm formation on cholesterol gallstones. These studies provide new therapeutic targets for preventing asymptomatic serovar Typhi gallbladder carriage.

* Corresponding author. Mailing address: The Ohio State University, Center for Microbial Interface Biology, 460 W. 12th Ave., Biomedical Research Tower, Room 1006, Columbus, OH 43210. Phone: (614) 292-6036. Fax: (614) 292-5495. E-mail: gunn.43{at}osu.edu

{triangledown} Published ahead of print on 15 September 2008.

Editor: F. C. Fang

Infection and Immunity, November 2008, p. 5341-5349, Vol. 76, No. 11
0019-9567/08/$08.00+0     doi:10.1128/IAI.00786-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Merritt, M. E., Donaldson, J. R. (2009). Effect of bile salts on the DNA and membrane integrity of enteric bacteria. J Med Microbiol 58: 1533-1541 [Abstract] [Full Text]  
  • Prieto, A. I., Hernandez, S. B., Cota, I., Pucciarelli, M. G., Orlov, Y., Ramos-Morales, F., Garcia-del Portillo, F., Casadesus, J. (2009). Roles of the Outer Membrane Protein AsmA of Salmonella enterica in the Control of marRAB Expression and Invasion of Epithelial Cells. J. Bacteriol. 191: 3615-3622 [Abstract] [Full Text]  
  • Ruas-Madiedo, P., Gueimonde, M., Arigoni, F., de los Reyes-Gavilan, C. G., Margolles, A. (2009). Bile Affects the Synthesis of Exopolysaccharides by Bifidobacterium animalis. Appl. Environ. Microbiol. 75: 1204-1207 [Abstract] [Full Text]  


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