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 White, A. P.
Right arrow Articles by Surette, M. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by White, A. P.
Right arrow Articles by Surette, M. G.

 Previous Article  |  Next Article 

Infection and Immunity, March 2008, p. 1048-1058, Vol. 76, No. 3
0019-9567/08/$08.00+0     doi:10.1128/IAI.01383-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Aggregation via the Red, Dry, and Rough Morphotype Is Not a Virulence Adaptation in Salmonella enterica Serovar Typhimurium{triangledown}

A. P. White,1 D. L. Gibson,2,{dagger} G. A. Grassl,3,{dagger} W. W. Kay,4 B. B. Finlay,3,5 B. A. Vallance,2 and M. G. Surette1*

Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta T2N 4N1, Canada,1 Division of Gastroenterology, BC's Children's Hospital, University of British Columbia, Vancouver BC V5Z 4H4, Canada,2 Michael Smith Laboratories, University of British Columbia, Vancouver BC V6T 1Z4, Canada,3 Department of Biochemistry and Microbiology, University of Victoria, Victoria BC V8W 3P6, Canada,4 Department of Microbiology and Immunology, University of British Columbia, Vancouver BC V6T 1Z4, Canada5

Received 16 October 2007/ Returned for modification 19 November 2007/ Accepted 19 December 2007

The Salmonella rdar (red, dry, and rough) morphotype is an aggregative and resistant physiology that has been linked to survival in nutrient-limited environments. Growth of Salmonella enterica serovar Typhimurium was analyzed in a variety of nutrient-limiting conditions to determine whether aggregation would occur at low cell densities and whether the rdar morphotype was involved in this process. The resulting cultures consisted of two populations of cells, aggregated and nonaggregated, with the aggregated cells preferentially displaying rdar morphotype gene expression. The two groups of cells could be separated based on the principle that aggregated cells were producing greater amounts of thin aggregative fimbriae (Tafi or curli). In addition, the aggregated cells retained some physiological characteristics of the rdar morphotype, such as increased resistance to sodium hypochlorite. Competitive infection experiments in mice showed that nonaggregative {Delta}agfA cells outcompeted rdar-positive wild-type cells in all tissues analyzed, indicating that aggregation via the rdar morphotype was not a virulence adaptation in Salmonella enterica serovar Typhimurium. Furthermore, in vivo imaging experiments showed that Tafi genes were not expressed during infection but were expressed once Salmonella was passed out of the mice into the feces. We hypothesize that the primary role of the rdar morphotype is to enhance Salmonella survival outside the host, thereby aiding in transmission.

* Corresponding author. Mailing address: Department of Microbiology and Infectious Diseases, University of Calgary, Faculty of Medicine, 268 Heritage Medical Research Building, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada. Phone: (403) 220-2744. Fax: (403) 270-2772. E-mail: surette{at}ucalgary.ca

{triangledown} Published ahead of print on 14 January 2008.

Editor: A. J. Bäumler

{dagger} These authors contributed equally to this work.

Infection and Immunity, March 2008, p. 1048-1058, Vol. 76, No. 3
0019-9567/08/$08.00+0     doi:10.1128/IAI.01383-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Apel, D., White, A. P., Grassl, G. A., Finlay, B. B., Surette, M. G. (2009). Long-Term Survival of Salmonella enterica Serovar Typhimurium Reveals an Infectious State That Is Underrepresented on Laboratory Media Containing Bile Salts. Appl. Environ. Microbiol. 75: 4923-4925 [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»