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David A, Tahrioui A, Duchesne R, Tareau AS, Maillot O, Barreau M, Feuilloley MGJ, Lesouhaitier O, Cornelis P, Bouffartigues E, Chevalier S. Membrane fluidity homeostasis is required for tobramycin-enhanced biofilm in Pseudomonas aeruginosa. Microbiol Spectr 2024; 12:e0230323. [PMID: 38411953 PMCID: PMC10986583 DOI: 10.1128/spectrum.02303-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 02/04/2024] [Indexed: 02/28/2024] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen, which causes chronic infections, especially in cystic fibrosis (CF) patients where it colonizes the lungs via the build-up of biofilms. Tobramycin, an aminoglycoside, is often used to treat P. aeruginosa infections in CF patients. Tobramycin at sub-minimal inhibitory concentrations enhances both biofilm biomass and thickness in vitro; however, the mechanism(s) involved are still unknown. Herein, we show that tobramycin increases the expression and activity of SigX, an extracytoplasmic sigma factor known to be involved in the biosynthesis of membrane lipids and membrane fluidity homeostasis. The biofilm enhancement by tobramycin is not observed in a sigX mutant, and the sigX mutant displays increased membrane stiffness. Remarkably, the addition of polysorbate 80 increases membrane fluidity of sigX-mutant cells in biofilm, restoring the tobramycin-enhanced biofilm formation. Our results suggest the involvement of membrane fluidity homeostasis in biofilm development upon tobramycin exposure.IMPORTANCEPrevious studies have shown that sub-lethal concentrations of tobramycin led to an increase biofilm formation in the case of infections with the opportunistic pathogen Pseudomonas aeruginosa. We show that the mechanism involved in this phenotype relies on the cell envelope stress response, triggered by the extracytoplasmic sigma factor SigX. This phenotype was abolished in a sigX-mutant strain. Remarkably, we show that increasing the membrane fluidity of the mutant strain is sufficient to restore the effect of tobramycin. Altogether, our data suggest the involvement of membrane fluidity homeostasis in biofilm development upon tobramycin exposure.
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Affiliation(s)
- Audrey David
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Ali Tahrioui
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Rachel Duchesne
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Anne-Sophie Tareau
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Olivier Maillot
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Magalie Barreau
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Marc G. J. Feuilloley
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Olivier Lesouhaitier
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Pierre Cornelis
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Emeline Bouffartigues
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
| | - Sylvie Chevalier
- Unité de recherche Communication Bactérienne et Stratégies Anti-infectieuses, CBSA UR4312, Université de Rouen Normandie, Normandie Université, Evreux, France
- Fédération de Recherche Normande Sécurité Sanitaire, bien être, Aliment Durable (SéSAD), Evreux, France
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Tortuel D, Tahrioui A, Rodrigues S, Cambronel M, Boukerb AM, Maillot O, Verdon J, Bere E, Nusser M, Brenner-Weiss G, David A, Azuama OC, Feuilloley MGJ, Orange N, Lesouhaitier O, Cornelis P, Chevalier S, Bouffartigues E. Activation of the Cell Wall Stress Response in Pseudomonas aeruginosa Infected by a Pf4 Phage Variant. Microorganisms 2020; 8:E1700. [PMID: 33143386 DOI: 10.3390/microorganisms8111700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa PAO1 has an integrated Pf4 prophage in its genome, encoding a relatively well-characterized filamentous phage, which contributes to the bacterial biofilm organization and maturation. Pf4 variants are considered as superinfectives when they can re-infect and kill the prophage-carrying host. Herein, the response of P. aeruginosa H103 to Pf4 variant infection was investigated. This phage variant caused partial lysis of the bacterial population and modulated H103 physiology. We show by confocal laser scanning microscopy that a Pf4 variant-infection altered P. aeruginosa H103 biofilm architecture either in static or dynamic conditions. Interestingly, in the latter condition, numerous cells displayed a filamentous morphology, suggesting a link between this phenotype and flow-related forces. In addition, Pf4 variant-infection resulted in cell envelope stress response, mostly mediated by the AlgU and SigX extracytoplasmic function sigma factors (ECFσ). AlgU and SigX involvement may account, at least partly, for the enhanced expression level of genes involved in the biosynthesis pathways of two matrix exopolysaccharides (Pel and alginates) and bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) metabolism.
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Bouffartigues E, Moscoso JA, Duchesne R, Rosay T, Fito-Boncompte L, Gicquel G, Maillot O, Bénard M, Bazire A, Brenner-Weiss G, Lesouhaitier O, Lerouge P, Dufour A, Orange N, Feuilloley MGJ, Overhage J, Filloux A, Chevalier S. The absence of the Pseudomonas aeruginosa OprF protein leads to increased biofilm formation through variation in c-di-GMP level. Front Microbiol 2015; 6:630. [PMID: 26157434 PMCID: PMC4477172 DOI: 10.3389/fmicb.2015.00630] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/09/2015] [Indexed: 11/13/2022] Open
Abstract
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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Affiliation(s)
- Emeline Bouffartigues
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Joana A Moscoso
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London London, UK
| | - Rachel Duchesne
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Thibaut Rosay
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Laurène Fito-Boncompte
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Gwendoline Gicquel
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Olivier Maillot
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Magalie Bénard
- Cell Imaging Platform of Normandy (PRIMACEN), Institute for Research and Innovation in Biomedicine, University of Rouen Mont-Saint-Aignan, France
| | - Alexis Bazire
- EA 3884-Laboratoire de Biotechnologie et Chimie Marines, Institut Universitaire Européen de la Mer, Université de Bretagne-Sud Lorient, France
| | - Gerald Brenner-Weiss
- Institute of Functional Interfaces, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Olivier Lesouhaitier
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Patrice Lerouge
- Glyco-MeV Laboratory, University of Rouen, Normandy University Mont-Saint-Aignan, France
| | - Alain Dufour
- EA 3884-Laboratoire de Biotechnologie et Chimie Marines, Institut Universitaire Européen de la Mer, Université de Bretagne-Sud Lorient, France
| | - Nicole Orange
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Marc G J Feuilloley
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
| | - Joerg Overhage
- Institute of Functional Interfaces, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London London, UK
| | - Sylvie Chevalier
- EA 4312-Laboratory of Microbiology Signals and Microenvironment, University of Rouen - Normandy University Evreux, France
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Bouffartigues E, Duchesne R, Bazire A, Simon M, Maillot O, Dufour A, Feuilloley M, Orange N, Chevalier S. Sucrose favors Pseudomonas aeruginosa pellicle production through the extracytoplasmic function sigma factor SigX. FEMS Microbiol Lett 2014; 356:193-200. [PMID: 24861220 DOI: 10.1111/1574-6968.12482] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 05/16/2014] [Accepted: 05/16/2014] [Indexed: 11/28/2022] Open
Abstract
Pseudomonas aeruginosa biofilm formation was increased by addition of sucrose to Luria-Bertani medium, whereas addition of NaCl to a final similar osmolarity and use of maltose instead of sucrose, were ineffective. In a previous study, we showed that the extracytoplasmic sigma factor SigX is activated in the presence of sucrose. The sucrose-mediated pellicle increase was abolished in a sigX mutant strain. Sucrose addition led to an increase in pel expression and cyclic-diguanylate (c-di-GMP) pool level production. Interestingly, these two phenotypes were strongly decreased in a sigX mutant. Since pel is not known as a SigX-target, we suspect SigX to be involved in the c-di-GMP production. We found that expression of the diguanylate cyclase PA4843 gene was increased in the presence of sucrose at least partly through SigX activity. Our study shows that sucrose itself rather than osmolarity favours the biofilm mode of P. aeruginosa through the activation of SigX.
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Affiliation(s)
- Emeline Bouffartigues
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM), EA 4312, Normandie Université, Université de Rouen, Rouen, France
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