Skip to main content

The Evolution of Quorum Sensing in Bacterial Biofilms

Author(s): Nadell, Carey D.; Xavier, Joao B.; Levin, Simon A.; Foster, Kevin R.

Download
To refer to this page use: http://arks.princeton.edu/ark:/88435/pr1jx44
Abstract: Bacteria have fascinating and diverse social lives. They display coordinated group behaviors regulated by quorum sensing systems that detect the density of other bacteria around them. A key example of such group behavior is biofilm formation, in which communities of cells attach to a surface and envelope themselves in secreted polymers. Curiously, after reaching high cell density, some bacterial species activate polymer secretion, whereas others terminate polymer secretion. Here, we investigate this striking variation in the first evolutionary model of quorum sensing in biofilms. We use detailed individual-based simulations to investigate evolutionary competitions between strains that differ in their polymer production and quorum-sensing phenotypes. The benefit of activating polymer secretion at high cell density is relatively straightforward: secretion starts upon biofilm formation, allowing strains to push their lineages into nutrient-rich areas and suffocate neighboring cells. But why use quorum sensing to terminate polymer secretion at high cell density? We find that deactivating polymer production in biofilms can yield an advantage by redirecting resources into growth, but that this advantage occurs only in a limited time window. We predict, therefore, that down-regulation of polymer secretion at high cell density will evolve when it can coincide with dispersal events, but it will be disfavored in long-lived (chronic) biofilms with sustained competition among strains. Our model suggests that the observed variation in quorum-sensing behavior can be linked to the differing requirements of bacteria in chronic versus acute biofilm infections. This is well illustrated by the case of Vibrio cholerae, which competes within biofilms by polymer secretion, terminates polymer secretion at high cell density, and induces an acute disease course that ends with mass dispersal from the host. More generally, this work shows that the balance of competition within and among biofilms can be pivotal in the evolution of quorum sensing.
Publication Date: 29-Jan-2008
Electronic Publication Date: 29-Jan-2008
Citation: Nadell, Carey D., Xavier, Joao B., Levin, Simon A., Foster, Kevin R. (2008). The Evolution of Quorum Sensing in Bacterial Biofilms. PLoS Biology, 6 (1), e14 - e14. doi:10.1371/journal.pbio.0060014
DOI: doi:10.1371/journal.pbio.0060014
EISSN: 1545-7885
Pages: e14 - e14
Type of Material: Journal Article
Journal/Proceeding Title: PLoS Biology
Version: Final published version. This is an open access article.



Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.