Virulence factors are released from Pseudomonas aeruginosa in association with membrane vesicles during normal growth and exposure to gentamicin: a novel mechanism of enzyme secretion

Kadurugamuwa, Jagath L.; Beveridge, Terry J.

doi:10.1128/jb.177.14.3998-4008.1995

Cited by 579 publications

(686 citation statements)

References 54 publications

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“…These environments often have high concentrations of extracellular DNA as a result of cell lysis, although some bacteria actively secrete DNA through type IV secretion systems or membrane vesicles (Hamilton & Dillard, 2006;Kadurugamuwa & Beveridge, 1995). It has been estimated that the lysis of a single cell can increase local DNA concentrations to above 100 mg ml 21 (Baur et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Biological and genetic factors regulating natural competence in a bacterial plant pathogen

Kung

Almeida

2014

Microbiology

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For naturally competent bacteria, spatially structured growth can provide an environment for enhanced horizontal gene transfer through transformation and recombination. DNA is often present in the extracellular environment, such as in the extracellular matrix of biofilms, and the lysis of a single cell can result in high local DNA concentrations. Xylella fastidiosa is a naturally competent plant pathogen that typically lives in a surface-attached state, yet previous work characterizing the competence of this organism was conducted with planktonic cells in liquid environments. Here, we show that transformation and recombination efficiencies are two to three orders of magnitude higher for cells grown on solid compared with liquid media, with maximum recombination efficiencies of about 10−3. Cells were highly competent throughout their exponential growth phase, with no significant change in recombination efficiencies until population growth rates began to slow. Mutations in type IV pili, competency-related, and cell–cell signalling genes significantly impacted the ability of X. fastidiosa to acquire and incorporate DNA. Because X. fastidiosa is highly competent when growing in a surface-attached state, as it does within its insect vectors and host plants, recombination of naturally transformed DNA could be a significant route by which horizontal gene transfer occurs in natural environments.

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Section: Introductionmentioning

confidence: 99%

Biological and genetic factors regulating natural competence in a bacterial plant pathogen

Kung

Almeida

2014

Microbiology

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“…However, under normal cellular growth conditions, the accumulation of OMPs should not be a serious problem in a bacterial cell, because they are diluted upon bacterial growth and division as new OMPs are biosynthesized [18]. In addition, Escherichia coli and other Gram-negative bacteria dispose of their outer membranes by blebbing off outer membrane vesicles whose composition includes outer membranes, outer membrane proteins and periplasmic components [19][20][21].…”

Section: Introduction: the Challenges Of Unfolded Outer Membrane Protmentioning

confidence: 99%

A combined kinetic push and thermodynamic pull as driving forces for outer membrane protein sorting and folding in bacteria

Fleming

2015

Phil. Trans. R. Soc. B

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One contribution of 12 to a theme issue 'The bacterial cell envelope'. In vitro folding studies of outer membrane beta-barrels have been invaluable in revealing the lipid effects on folding rates and efficiencies as well as folding free energies. Here, the biophysical results are summarized, and these kinetic and thermodynamic findings are considered in terms of the requirements for folding in the context of the cellular environment. Because the periplasm lacks an external energy source the only driving forces for sorting and folding available within this compartment are binding or folding free energies and their associated rates. These values define functions for periplasmic chaperones and suggest a biophysical mechanism for the BAM complex.

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“…It has been suggested that anionic repulsion between neighboring LPS molecules induces MV production in Gram-negative bacteria (12). Because PQS strongly interacts with LPS (26), the anionic repulsion is considered to be enhanced by the addition of PQS, resulting in increased MV production.…”

Section: Effects Of Magnesium On MV Productionmentioning

confidence: 99%

Pseudomonas Quinolone Signal Affects Membrane Vesicle Production in not only Gram-Negative but also Gram-Positive Bacteria

et al. 2010

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Many Gram-negative bacteria naturally produce membrane vesicles (MVs) to the extracellular milieu. The Pseudomonas quinolone signal (PQS), a quorum-sensing signal of Pseudomonas aeruginosa, is a positive regulator of MV production. In this study, we investigated its effects on MV production in other Gram-negative and -positive bacterial species. The addition of PQS to an Escherichia coli K12 culture resulted in increased MV production and enlarged MVs. An excessive amount of MgCl 2 repressed E. coli MV production either with or without PQS, suggesting that an anionic repulsion of cellular surfaces increases MV production. PQS was found in the cellular membrane and MVs in E. coli. The enhancement of MV production by PQS occurred in other Gram-negative bacteria, including Burkholderia and Pseudomonas species. Moreover, PQS induced MV production in a Gram-positive bacterium, Bacillus subtilis 168, which does not normally produce MV under laboratory conditions. An excessive amount of MgCl 2 did not repress B. subtilis MV production in the presence of PQS, suggesting the production mechanism to be different from that in Gram-negative bacteria. Together, these results indicated that PQS enhances MV production in Gram-negative bacteria and induces it in Gram-positive bacteria.

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Virulence factors are released from Pseudomonas aeruginosa in association with membrane vesicles during normal growth and exposure to gentamicin: a novel mechanism of enzyme secretion

Cited by 579 publications

References 54 publications

Biological and genetic factors regulating natural competence in a bacterial plant pathogen

Biological and genetic factors regulating natural competence in a bacterial plant pathogen

A combined kinetic push and thermodynamic pull as driving forces for outer membrane protein sorting and folding in bacteria

Pseudomonas Quinolone Signal Affects Membrane Vesicle Production in not only Gram-Negative but also Gram-Positive Bacteria

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