Bacteria form biofilms to survive and proliferate in a wide range of conditions. However, the physiological roles of biofilms produced by commensal microbiota remain largely unknown. To assess the impact of a bacterial biofilm on host physiology we explored the Caenorhabditis elegans - Bacillus subtilis commensal pair. We found that biofilm formation by B. subtilis augments C. elegans stress resistance, protects against pathogenic infection, and prolongs lifespan. Additionally, we showed that these beneficial effects might be due to B. subtilis biofilm formation in the nematodes intestinal lumen. Next, we identified a set of host genes that are upregulated in response to biofilm-forming B. subtilis, demonstrating a specific response to the commensal biofilm. We show that mtl-1 is responsible for the biofilm-mediated increase in oxidative stress resistance and lifespan extension. Induction of mtl-1 and hsp-70 also accounts for biofilm-mediated thermotolerance. Additionally, ilys-2 activity accounts for biofilm-mediated resistance to Pseudomonas aeruginosa killing. These results reveal the importance of commensal biofilms for host robustness and provide a framework in which to study non-pathogenic biofilms in higher organisms.
|Commitee:||Darwin, Andrew, Nance, Jeremy, Ziff, Edward|
|School:||New York University|
|Department:||Basic Medical Science|
|School Location:||United States -- New York|
|Source:||DAI-B 79/01(E), Dissertation Abstracts International|
|Subjects:||Molecular biology, Cellular biology, Microbiology|
|Keywords:||Aging, Biofilm, Caenorhabditis elegans, Commensal microbiota, Stress response|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be