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 Thomas, V. C.
Right arrow Articles by Hancock, L. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Thomas, V. C.
Right arrow Articles by Hancock, L. E.

 Previous Article  |  Next Article 

Journal of Bacteriology, August 2008, p. 5690-5698, Vol. 190, No. 16
0021-9193/08/$08.00+0     doi:10.1128/JB.00314-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Regulation of Autolysis-Dependent Extracellular DNA Release by Enterococcus faecalis Extracellular Proteases Influences Biofilm Development{triangledown}

Vinai Chittezham Thomas, Lance R. Thurlow, Dan Boyle, and Lynn E. Hancock*

Division of Biology, Kansas State University, Manhattan, Kansas 66502

Received 2 February 2008/ Accepted 5 June 2008

Enterococci are major contributors of hospital-acquired infections and have emerged as important reservoirs for the dissemination of antibiotic resistance traits. The ability to form biofilms on medical devices is an important aspect of pathogenesis in the hospital environment. The Enterococcus faecalis Fsr quorum system has been shown to regulate biofilm formation through the production of gelatinase, but the mechanism has been hitherto unknown. Here we show that both gelatinase (GelE) and serine protease (SprE) contribute to biofilm formation by E. faecalis and provide clues to how the activity of these proteases governs this developmental process. Confocal imaging of biofilms suggested that GelE– mutants were significantly reduced in biofilm biomass compared to the parental strain, whereas the absence of SprE appeared to accelerate the progression of biofilm development. The phenotype observed in a SprE– mutant was linked to an observed increase in autolytic rate compared to the parental strain. Culture supernatant analysis and confocal microscopy confirmed the inability of mutants deficient in GelE to release extracellular DNA (eDNA) in planktonic and biofilm cultures, whereas cells deficient in SprE produced significantly more eDNA as a component of the biofilm matrix. DNase I treatment of E. faecalis biofilms reduced the accumulation of biofilm, implying a critical role for eDNA in biofilm development. In conclusion, our data suggest that the interplay of two secreted and coregulated proteases—GelE and SprE—is responsible for regulating autolysis and the release of high-molecular-weight eDNA, a critical component for the development of E. faecalis biofilms.

* Corresponding author. Mailing address: Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506. Phone: (785) 532-6122. Fax: (785) 532-6653. E-mail: lynnh{at}ksu.edu

{triangledown} Published ahead of print on 13 June 2008.

Journal of Bacteriology, August 2008, p. 5690-5698, Vol. 190, No. 16
0021-9193/08/$08.00+0     doi:10.1128/JB.00314-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Kreth, J., Vu, H., Zhang, Y., Herzberg, M. C. (2009). Characterization of Hydrogen Peroxide-Induced DNA Release by Streptococcus sanguinis and Streptococcus gordonii. J. Bacteriol. 191: 6281-6291 [Abstract] [Full Text]  
  • Guiton, P. S., Hung, C. S., Kline, K. A., Roth, R., Kau, A. L., Hayes, E., Heuser, J., Dodson, K. W., Caparon, M. G., Hultgren, S. J. (2009). Contribution of Autolysin and Sortase A during Enterococcus faecalis DNA-Dependent Biofilm Development. Infect. Immun. 77: 3626-3638 [Abstract] [Full Text]  
  • Karatan, E., Watnick, P. (2009). Signals, Regulatory Networks, and Materials That Build and Break Bacterial Biofilms. Microbiol. Mol. Biol. Rev. 73: 310-347 [Abstract] [Full Text]  
  • Lauderdale, K. J., Boles, B. R., Cheung, A. L., Horswill, A. R. (2009). Interconnections between Sigma B, agr, and Proteolytic Activity in Staphylococcus aureus Biofilm Maturation. Infect. Immun. 77: 1623-1635 [Abstract] [Full Text]  
  • Mann, E., Zaunbrecher, M. A, Hitz, K., Churchward, G. (2008). The 52nd Annual Wind River Conference on Prokaryotic Biology--2008. J. Bacteriol. 190: 7871-7875 [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»