Social cheating in Pseudomonas aeruginosa quorum sensing

@article{citeulike:1702688, abstract = {Edited by E. Peter Greenberg, University of Washington School of Medicine, Seattle, WA, and approved August 13, 2007 (received for review June 15, 2007)In a process termed quorum sensing, bacteria use diffusible chemical signals to coordinate cell density-dependent gene expression. In the human pathogen Pseudomonas aeruginosa, quorum sensing controls hundreds of genes, many of which encode extracellular virulence factors. Quorum sensing is required for P. aeruginosa virulence in animal models. Curiously, quorum sensing-deficient variants, most of which carry a mutation in the gene encoding the central quorum sensing regulator lasR, are frequently isolated from acute and chronic infections. The mechanism for their emergence is not known. Here we provide experimental evidence suggesting that these lasR mutants are social cheaters that cease production of quorum-controlled factors and take advantage of their production by the group. We detected an emerging subpopulation of lasR mutants after {approx}100 generations of in vitro evolution of the P. aeruginosa wild-type strain under culture conditions that require quorum sensing for growth. Under such conditions, quorum sensing appears to impose a metabolic burden on the proliferating bacterial cell, because quorum-controlled genes not normally induced until cessation of growth were highly expressed early in growth, and a defined lasR mutant showed a growth advantage when cocultured with the parent strain. The emergence of quorum-sensing-deficient variants in certain environments is therefore an indicator of high quorum sensing activity of the bacterial population as a whole. It does not necessarily indicate that quorum sensing is insignificant, as has previously been suggested. Thus, novel antivirulence strategies aimed at disrupting bacterial communication may be particularly effective in such clinical settings. 10.1073/pnas.0705653104}, author = {Sandoz, Kelsi M. and Mitzimberg, Shelby M. and Schuster, Martin }, citeulike-article-id = {1702688}, doi = {10.1073/pnas.0705653104}, journal = {Proceedings of the National Academy of Sciences}, keywords = {pseudomonas, quorum-sensing, social}, month = {September}, pages = {0705653104+}, posted-at = {2007-09-27 20:39:01}, priority = {5}, title = {Social cheating in Pseudomonas aeruginosa quorum sensing}, url = {http://dx.doi.org/10.1073/pnas.0705653104}, year = {2007} }

TY - JOUR ID - citeulike:1702688 L3 - citeulike-article-id:1702688 TI - Social cheating in Pseudomonas aeruginosa quorum sensing JF - Proceedings of the National Academy of Sciences SP - 0705653104 N2 - Edited by E. Peter Greenberg, University of Washington School of Medicine, Seattle, WA, and approved August 13, 2007 (received for review June 15, 2007)In a process termed quorum sensing, bacteria use diffusible chemical signals to coordinate cell density-dependent gene expression. In the human pathogen Pseudomonas aeruginosa, quorum sensing controls hundreds of genes, many of which encode extracellular virulence factors. Quorum sensing is required for P. aeruginosa virulence in animal models. Curiously, quorum sensing-deficient variants, most of which carry a mutation in the gene encoding the central quorum sensing regulator lasR, are frequently isolated from acute and chronic infections. The mechanism for their emergence is not known. Here we provide experimental evidence suggesting that these lasR mutants are social cheaters that cease production of quorum-controlled factors and take advantage of their production by the group. We detected an emerging subpopulation of lasR mutants after {approx}100 generations of in vitro evolution of the P. aeruginosa wild-type strain under culture conditions that require quorum sensing for growth. Under such conditions, quorum sensing appears to impose a metabolic burden on the proliferating bacterial cell, because quorum-controlled genes not normally induced until cessation of growth were highly expressed early in growth, and a defined lasR mutant showed a growth advantage when cocultured with the parent strain. The emergence of quorum-sensing-deficient variants in certain environments is therefore an indicator of high quorum sensing activity of the bacterial population as a whole. It does not necessarily indicate that quorum sensing is insignificant, as has previously been suggested. Thus, novel antivirulence strategies aimed at disrupting bacterial communication may be particularly effective in such clinical settings. 10.1073/pnas.0705653104 KW - pseudomonas KW - quorum-sensing KW - social AU - Sandoz, Kelsi AU - Mitzimberg, Shelby AU - Schuster, Martin PY - 2007/09/26/ UR - http://dx.doi.org/10.1073/pnas.0705653104 ER -