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Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa
BACKGROUND: Acyl-homoserine lactone (acyl-HSL) and alkyl quinolone (AQ) based quorum-sensing (QS) systems are important for Pseudomonas aeruginosa virulence and biofilm formation. The effect of QS on biofilm formation is influenced by various genetic and environmental factors. Here, we used a colony...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2012
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364869/ https://www.ncbi.nlm.nih.gov/pubmed/22404951 http://dx.doi.org/10.1186/1471-2180-12-30 |
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author | Gupta, Rashmi Schuster, Martin |
author_facet | Gupta, Rashmi Schuster, Martin |
author_sort | Gupta, Rashmi |
collection | PubMed |
description | BACKGROUND: Acyl-homoserine lactone (acyl-HSL) and alkyl quinolone (AQ) based quorum-sensing (QS) systems are important for Pseudomonas aeruginosa virulence and biofilm formation. The effect of QS on biofilm formation is influenced by various genetic and environmental factors. Here, we used a colony biofilm assay to study the effect of the central acyl-HSL QS regulator, LasR, on biofilm formation and structure in the representative clinical P. aeruginosa isolate ZK2870. RESULTS: A lasR mutant exhibited wrinkled colony morphology at 37°C in contrast to the smooth colony morphology of the wild-type. Mutational analysis indicated that wrinkling of the lasR mutant is dependent on pel, encoding a biofilm matrix exopolysaccharide. Suppressor mutagenesis and complementation analysis implicated the AQ signaling pathway as the link between las QS and colony morphology. In this pathway, genes pqsA-D are involved in the synthesis of 4-hydroxyalkyl quinolines ("Series A congeners"), which are converted to 3,4-dihydroxyalkyl quinolines ("Series B congeners", including the well-characterized Pseudomonas Quinolone Signal, PQS) by the product of the LasR-dependent pqsH gene. Measurement of AQ in the wild-type, the lasR pqsA::Tn suppressor mutant as well as the defined lasR, pqsH, and lasR pqsH mutants showed a correlation between 4-hydroxyalkyl quinoline levels and the degree of colony wrinkling. Most importantly, the lasR pqsH double mutant displayed wrinkly morphology without producing any 3,4-dihydroxyalkyl quinolines. Constitutive expression of pqsA-D genes in a lasR pqsR::Tnmutant showed that colony wrinkling does not require the AQ receptor PqsR. CONCLUSIONS: Taken together, these results indicate that the las QS system represses Pel and modulates colony morphology through a 4-hydroxyalkyl quinoline in a PqsR-independent manner, ascribing a novel function to an AQ other than PQS in P. aeruginosa. |
format | Online Article Text |
id | pubmed-3364869 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-33648692012-06-01 Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa Gupta, Rashmi Schuster, Martin BMC Microbiol Research Article BACKGROUND: Acyl-homoserine lactone (acyl-HSL) and alkyl quinolone (AQ) based quorum-sensing (QS) systems are important for Pseudomonas aeruginosa virulence and biofilm formation. The effect of QS on biofilm formation is influenced by various genetic and environmental factors. Here, we used a colony biofilm assay to study the effect of the central acyl-HSL QS regulator, LasR, on biofilm formation and structure in the representative clinical P. aeruginosa isolate ZK2870. RESULTS: A lasR mutant exhibited wrinkled colony morphology at 37°C in contrast to the smooth colony morphology of the wild-type. Mutational analysis indicated that wrinkling of the lasR mutant is dependent on pel, encoding a biofilm matrix exopolysaccharide. Suppressor mutagenesis and complementation analysis implicated the AQ signaling pathway as the link between las QS and colony morphology. In this pathway, genes pqsA-D are involved in the synthesis of 4-hydroxyalkyl quinolines ("Series A congeners"), which are converted to 3,4-dihydroxyalkyl quinolines ("Series B congeners", including the well-characterized Pseudomonas Quinolone Signal, PQS) by the product of the LasR-dependent pqsH gene. Measurement of AQ in the wild-type, the lasR pqsA::Tn suppressor mutant as well as the defined lasR, pqsH, and lasR pqsH mutants showed a correlation between 4-hydroxyalkyl quinoline levels and the degree of colony wrinkling. Most importantly, the lasR pqsH double mutant displayed wrinkly morphology without producing any 3,4-dihydroxyalkyl quinolines. Constitutive expression of pqsA-D genes in a lasR pqsR::Tnmutant showed that colony wrinkling does not require the AQ receptor PqsR. CONCLUSIONS: Taken together, these results indicate that the las QS system represses Pel and modulates colony morphology through a 4-hydroxyalkyl quinoline in a PqsR-independent manner, ascribing a novel function to an AQ other than PQS in P. aeruginosa. BioMed Central 2012-03-09 /pmc/articles/PMC3364869/ /pubmed/22404951 http://dx.doi.org/10.1186/1471-2180-12-30 Text en Copyright ©2012 Gupta and Schuster; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Gupta, Rashmi Schuster, Martin Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title | Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title_full | Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title_fullStr | Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title_full_unstemmed | Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title_short | Quorum sensing modulates colony morphology through alkyl quinolones in Pseudomonas aeruginosa |
title_sort | quorum sensing modulates colony morphology through alkyl quinolones in pseudomonas aeruginosa |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364869/ https://www.ncbi.nlm.nih.gov/pubmed/22404951 http://dx.doi.org/10.1186/1471-2180-12-30 |
work_keys_str_mv | AT guptarashmi quorumsensingmodulatescolonymorphologythroughalkylquinolonesinpseudomonasaeruginosa AT schustermartin quorumsensingmodulatescolonymorphologythroughalkylquinolonesinpseudomonasaeruginosa |