Role of mutation in Pseudomonas aeruginosa biofilm development.

The survival of bacteria in nature is greatly enhanced by their ability to grow within surface-associated communities called biofilms. Commonly, biofilms generate proliferations of bacterial cells, called microcolonies, which are highly recalcitrant, 3-dimensional foci of bacterial growth. Microcolo...

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Main Authors: Tim C R Conibear, Samuel L Collins, Jeremy S Webb
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2009-07-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0006289&type=printable
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author Tim C R Conibear
Samuel L Collins
Jeremy S Webb
author_facet Tim C R Conibear
Samuel L Collins
Jeremy S Webb
author_sort Tim C R Conibear
collection DOAJ
description The survival of bacteria in nature is greatly enhanced by their ability to grow within surface-associated communities called biofilms. Commonly, biofilms generate proliferations of bacterial cells, called microcolonies, which are highly recalcitrant, 3-dimensional foci of bacterial growth. Microcolony growth is initiated by only a subpopulation of bacteria within biofilms, but processes responsible for this differentiation remain poorly understood. Under conditions of crowding and intense competition between bacteria within biofilms, microevolutionary processes such as mutation selection may be important for growth; however their influence on microcolony-based biofilm growth and architecture have not previously been explored. To study mutation in-situ within biofilms, we transformed Pseudomonas aeruginosa cells with a green fluorescent protein gene containing a +1 frameshift mutation. Transformed P. aeruginosa cells were non-fluorescent until a mutation causing reversion to the wildtype sequence occurs. Fluorescence-inducing mutations were observed in microcolony structures, but not in other biofilm cells, or in planktonic cultures of P. aeruginosa cells. Thus microcolonies may represent important foci for mutation and evolution within biofilms. We calculated that microcolony-specific increases in mutation frequency were at least 100-fold compared with planktonically grown cultures. We also observed that mutator phenotypes can enhance microcolony-based growth of P. aeruginosa cells. For P. aeruginosa strains defective in DNA fidelity and error repair, we found that microcolony initiation and growth was enhanced with increased mutation frequency of the organism. We suggest that microcolony-based growth can involve mutation and subsequent selection of mutants better adapted to grow on surfaces within crowded-cell environments. This model for biofilm growth is analogous to mutation selection that occurs during neoplastic progression and tumor development, and may help to explain why structural and genetic heterogeneity are characteristic features of bacterial biofilm populations.
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spelling doaj-art-1d97564a73bb4251ab6ecbb60d8a36692025-08-20T03:22:38ZengPublic Library of Science (PLoS)PLoS ONE1932-62032009-07-0147e628910.1371/journal.pone.0006289Role of mutation in Pseudomonas aeruginosa biofilm development.Tim C R ConibearSamuel L CollinsJeremy S WebbThe survival of bacteria in nature is greatly enhanced by their ability to grow within surface-associated communities called biofilms. Commonly, biofilms generate proliferations of bacterial cells, called microcolonies, which are highly recalcitrant, 3-dimensional foci of bacterial growth. Microcolony growth is initiated by only a subpopulation of bacteria within biofilms, but processes responsible for this differentiation remain poorly understood. Under conditions of crowding and intense competition between bacteria within biofilms, microevolutionary processes such as mutation selection may be important for growth; however their influence on microcolony-based biofilm growth and architecture have not previously been explored. To study mutation in-situ within biofilms, we transformed Pseudomonas aeruginosa cells with a green fluorescent protein gene containing a +1 frameshift mutation. Transformed P. aeruginosa cells were non-fluorescent until a mutation causing reversion to the wildtype sequence occurs. Fluorescence-inducing mutations were observed in microcolony structures, but not in other biofilm cells, or in planktonic cultures of P. aeruginosa cells. Thus microcolonies may represent important foci for mutation and evolution within biofilms. We calculated that microcolony-specific increases in mutation frequency were at least 100-fold compared with planktonically grown cultures. We also observed that mutator phenotypes can enhance microcolony-based growth of P. aeruginosa cells. For P. aeruginosa strains defective in DNA fidelity and error repair, we found that microcolony initiation and growth was enhanced with increased mutation frequency of the organism. We suggest that microcolony-based growth can involve mutation and subsequent selection of mutants better adapted to grow on surfaces within crowded-cell environments. This model for biofilm growth is analogous to mutation selection that occurs during neoplastic progression and tumor development, and may help to explain why structural and genetic heterogeneity are characteristic features of bacterial biofilm populations.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0006289&type=printable
spellingShingle Tim C R Conibear
Samuel L Collins
Jeremy S Webb
Role of mutation in Pseudomonas aeruginosa biofilm development.
PLoS ONE
title Role of mutation in Pseudomonas aeruginosa biofilm development.
title_full Role of mutation in Pseudomonas aeruginosa biofilm development.
title_fullStr Role of mutation in Pseudomonas aeruginosa biofilm development.
title_full_unstemmed Role of mutation in Pseudomonas aeruginosa biofilm development.
title_short Role of mutation in Pseudomonas aeruginosa biofilm development.
title_sort role of mutation in pseudomonas aeruginosa biofilm development
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0006289&type=printable
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AT jeremyswebb roleofmutationinpseudomonasaeruginosabiofilmdevelopment