Sucrose favors<i>Pseudomonas aeruginosa</i>pellicle production through the extracytoplasmic function sigma factor SigX

Bouffartigues, Emeline; Duchesne, Rachel; Bazire, Alexis; Simon, Marjolaine; Maillot, Olivier; Dufour, Alain; Feuilloley, Marc; Orange, Nicole; Chevalier, Sylvie

doi:10.1111/1574-6968.12482

Cited by 21 publications

(15 citation statements)

References 44 publications

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“…Remarkably, the OM proteome of a SigX deficient P. aeruginosa strain was shown to present a much lower abundance in OM porins (Duchesne et al, 2013 ). Moreover, the conditions leading to cell wall stress among which membrane perturbations, were shown to increase SigX activity resulting in enhancing adhesion and biofilm formation (Bouffartigues et al, 2014 , 2015 ). It may be conceivable that perception of an SS surface may occur via membrane or cell wall perturbations, leading to activation of the cell wall stress response of P. aeruginosa .…”

Section: Discussionmentioning

confidence: 99%

Proteomic Response of Pseudomonas aeruginosa PAO1 Adhering to Solid Surfaces

et al. 2017

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Pseudomonas aeruginosa is a pathogenic micro-organism responsible for many hospital-acquired infections. It is able to adhere to solid surfaces and develop an immobilized community or so-called biofilm. Many studies have been focusing on the use of specific materials to prevent the formation of these biofilms, but the reactivity of the bacteria in contact to surfaces remains unknown. The aim of this study was to evaluate the impact of the abiotic surface on the physiology of adherent bacteria. Three different materials, stainless steel (SS), glass (G), and polystyrene (PS) that were relevant to industrial or medical environments were characterized at the physicochemical level in terms of their hydrophobicity and roughness. We showed that SS was moderately hydrophilic and rough, potentially containing crevices, G was hydrophilic and smooth while PS was hydrophobic and smooth. We further showed that P. aeruginosa cells were more likely able to adhere to SS and G rather than PS surfaces under our experimental conditions. The physiological response of P. aeruginosa when adhering to each of these materials was then evaluated by global proteomic analysis. The abundance of 70 proteins was shown to differ between the materials suggesting that their abundance was modified as a function of the material to which bacteria adhered. Our data lead to enabling the identification of abundance patterns that appeared to be specific to a given surface. Taken together, our data showed that P. aeruginosa is capable of sensing and responding to a surface probably via specific programmes to adapt its physiological response accordingly.

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Section: Discussionmentioning

confidence: 99%

Proteomic Response of Pseudomonas aeruginosa PAO1 Adhering to Solid Surfaces

et al. 2017

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“…5 ). The Pel exopolysaccharide is required for the formation of pellicles at the ALI [ 85 ]. Using RT-qPCR we investigated the possibility that hepP influences pellicle formation through pelC or pelE (Additional file 1 : Table S1).…”

Section: Discussionmentioning

confidence: 99%

Isolation and characterization of HepP: a virulence-related Pseudomonas aeruginosa heparinase

et al. 2017

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Background Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections in immunocompromised hosts including severely burned patients. In burn patients, P. aeruginosa infection often leads to septic shock and death. Despite numerous studies, the influence of severe thermal injuries on the pathogenesis of P. aeruginosa during systemic infection is not known. Through RNA-seq analysis, we recently showed that the growth of P. aeruginosa strain UCBPP-PA14 (PA14) in whole blood obtained from severely burned patients significantly altered the expression of the PA14 transcriptome when compared with its growth in blood from healthy volunteers. The expression of PA14_23430 and the adjacent gene, PA14_23420, was enhanced by seven- to eightfold under these conditions.ResultsQuantitative real-time PCR analysis confirmed the enhancement of expression of both PA14_23420 and PA14_23430 by growth of PA14 in blood from severely burned patients. Computer analysis revealed that PA14_23430 (hepP) encodes a potential heparinase while PA14_23420 (zbdP) codes for a putative zinc-binding dehydrogenase. This analysis further suggested that the two genes form an operon with zbdP first. Presence of the operon was confirmed by RT-PCR experiments.We characterized hepP and its protein product HepP. hepP was cloned from PA14 by PCR and overexpressed in E. coli. The recombinant protein (rHepP) was purified using nickel column chromatography. Heparinase assays using commercially available heparinase as a positive control, revealed that rHepP exhibits heparinase activity. Mutation of hepP resulted in delay of pellicle formation at the air-liquid interface by PA14 under static growth conditions. Biofilm formation by PA14ΔhepP was also significantly reduced. In the Caenorhabditis elegans model of slow killing, mutation of hepP resulted in a significantly lower rate of killing than that of the parent strain PA14.ConclusionsChanges within the blood of severely burned patients significantly induced expression of hepP in PA14. The heparinase encoded by hepP is a potential virulence factor for PA14 as HepP influences pellicle formation as well as biofilm development by PA14 and the protein is required for full virulence in the C. elegans model of slow killing.Electronic supplementary materialThe online version of this article (10.1186/s12866-017-1141-0) contains supplementary material, which is available to authorized users.

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“…Quantification of biofilm formation was performed in 12-wells polystyrene microtiter plates as previously described ( Bouffartigues et al, 2014 ). Briefly, LB medium (2 ml per well) supplemented with appropriate antibiotics was inoculated to a final OD 580 of 0.08 (8.10 7 CFU.ml -1 ) and incubated at 37°C without shaking for 24 h. Biofilms were stained with 3 ml of 0.4% of crystal violet (CV) for 20 min at room temperature, and washed with 3 ml of water until removing the unbound dye.…”

Section: Methodsmentioning

confidence: 99%

The absence of the Pseudomonas aeruginosa OprF protein leads to increased biofilm formation through variation in c-di-GMP level

et al. 2015

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OprF is the major outer membrane porin in bacteria belonging to the Pseudomonas genus. In previous studies, we have shown that OprF is required for full virulence expression of the opportunistic pathogen Pseudomonas aeruginosa. Here, we describe molecular insights on the nature of this relationship and report that the absence of OprF leads to increased biofilm formation and production of the Pel exopolysaccharide. Accordingly, the level of c-di-GMP, a key second messenger in biofilm control, is elevated in an oprF mutant. By decreasing c-di-GMP levels in this mutant, both biofilm formation and pel gene expression phenotypes were restored to wild-type levels. We further investigated the impact on two small RNAs, which are associated with the biofilm lifestyle, and found that expression of rsmZ but not of rsmY was increased in the oprF mutant and this occurs in a c-di-GMP-dependent manner. Finally, the extracytoplasmic function (ECF) sigma factors AlgU and SigX displayed higher activity levels in the oprF mutant. Two genes of the SigX regulon involved in c-di-GMP metabolism, PA1181 and adcA (PA4843), were up-regulated in the oprF mutant, partly explaining the increased c-di-GMP level. We hypothesized that the absence of OprF leads to a cell envelope stress that activates SigX and results in a c-di-GMP elevated level due to higher expression of adcA and PA1181. The c-di-GMP level can in turn stimulate Pel synthesis via increased rsmZ sRNA levels and pel mRNA, thus affecting Pel-dependent phenotypes such as cell aggregation and biofilm formation. This work highlights the connection between OprF and c-di-GMP regulatory networks, likely via SigX (ECF), on the regulation of biofilm phenotypes.

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Sucrose favorsPseudomonas aeruginosapellicle production through the extracytoplasmic function sigma factor SigX

Cited by 21 publications

References 44 publications

Proteomic Response of Pseudomonas aeruginosa PAO1 Adhering to Solid Surfaces

Proteomic Response of Pseudomonas aeruginosa PAO1 Adhering to Solid Surfaces

Isolation and characterization of HepP: a virulence-related Pseudomonas aeruginosa heparinase

The absence of the Pseudomonas aeruginosa OprF protein leads to increased biofilm formation through variation in c-di-GMP level

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