1
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Yaeger LN, Ranieri MRM, Chee J, Karabelas-Pittman S, Rudolph M, Giovannoni AM, Harvey H, Burrows LL. A genetic screen identifies a role for oprF in Pseudomonas aeruginosa biofilm stimulation by subinhibitory antibiotics. NPJ Biofilms Microbiomes 2024; 10:30. [PMID: 38521769 PMCID: PMC10960818 DOI: 10.1038/s41522-024-00496-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/05/2024] [Indexed: 03/25/2024] Open
Abstract
Biofilms are surface-associated communities of bacteria that grow in a self-produced matrix of polysaccharides, proteins, and extracellular DNA (eDNA). Sub-minimal inhibitory concentrations (sub-MIC) of antibiotics induce biofilm formation, potentially as a defensive response to antibiotic stress. However, the mechanisms behind sub-MIC antibiotic-induced biofilm formation are unclear. We show that treatment of Pseudomonas aeruginosa with multiple classes of sub-MIC antibiotics with distinct targets induces biofilm formation. Further, addition of exogenous eDNA or cell lysate failed to increase biofilm formation to the same extent as antibiotics, suggesting that the release of cellular contents by antibiotic-driven bacteriolysis is insufficient. Using a genetic screen for stimulation-deficient mutants, we identified the outer membrane porin OprF and the ECF sigma factor SigX as important. Similarly, loss of OmpA - the Escherichia coli OprF homolog - prevented sub-MIC antibiotic stimulation of E. coli biofilms. Our screen also identified the periplasmic disulfide bond-forming enzyme DsbA and a predicted cyclic-di-GMP phosphodiesterase encoded by PA2200 as essential for biofilm stimulation. The phosphodiesterase activity of PA2200 is likely controlled by a disulfide bond in its regulatory domain, and folding of OprF is influenced by disulfide bond formation, connecting the mutant phenotypes. Addition of reducing agent dithiothreitol prevented sub-MIC antibiotic biofilm stimulation. Finally, activation of a c-di-GMP-responsive promoter follows treatment with sub-MIC antibiotics in the wild-type but not an oprF mutant. Together, these results show that antibiotic-induced biofilm formation is likely driven by a signaling pathway that translates changes in periplasmic redox state into elevated biofilm formation through increases in c-di-GMP.
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Affiliation(s)
- Luke N Yaeger
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Michael R M Ranieri
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Jessica Chee
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Sawyer Karabelas-Pittman
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Madeleine Rudolph
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Alessio M Giovannoni
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Hanjeong Harvey
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Lori L Burrows
- Biochemistry and Biomedical Sciences and the Michael G. DeGroote Centre for Infectious Disease Research, McMaster University, Hamilton, ON, Canada.
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2
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Mathur S, Erickson SK, Goldberg LR, Hills S, Radin AGB, Schertzer JW. OprF functions as a latch to direct Outer Membrane Vesicle release in Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.12.566662. [PMID: 37986865 PMCID: PMC10659412 DOI: 10.1101/2023.11.12.566662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Bacterial Outer Membrane Vesicles (OMVs) contribute to virulence, competition, immune avoidance and communication. This has led to great interest in how they are formed. To date, investigation has focused almost exclusively on what controls the initiation of OMV biogenesis. Regardless of the mechanism of initiation, all species face a similar challenge before an OMV can be released: How does the OM detach from the underlying peptidoglycan (PG) in regions that will ultimately bulge and then vesiculate? The OmpA family of OM proteins (OprF in P. aeruginosa) is widely conserved and unusually abundant in OMVs across species considering their major role in PG attachment. OmpA homologs also have the interesting ability to adopt both PG-bound (two-domain) and PG-released (one-domain) conformations. Using targeted deletion of the PG-binding domain we showed that loss of cell wall association, and not general membrane destabilization, is responsible for hypervesiculation in OprF-modified strains. We therefore propose that OprF functions as a 'latch', capable of releasing PG in regions destined to become OMVs. To test this hypothesis, we developed a protocol to assess OprF conformation in live cells and purified OMVs. While >90% of OprF proteins exist in the two-domain conformation in the OM of cells, we show that the majority of OprF in OMVs is present in the one-domain conformation. With this work, we take some of the first steps in characterizing late-stage OMV biogenesis and identify a family of proteins whose critical role can be explained by their unique ability to fold into two distinct conformations.
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Affiliation(s)
- Shrestha Mathur
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
| | - Susan K Erickson
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
| | - Leah R Goldberg
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
| | - Sonia Hills
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
| | - Abigail G B Radin
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
| | - Jeffrey W Schertzer
- Department of Biological Sciences, Binghamton University, Binghamton, NY 13902
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902
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3
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Blackwood CB, Mateu-Borrás M, Sen-Kilic E, Pyles GM, Miller SJ, Weaver KL, Witt WT, Huckaby AB, Kang J, Chandler CE, Ernst RK, Heath Damron F, Barbier M. Bordetella pertussis whole cell immunization protects against Pseudomonas aeruginosa infections. NPJ Vaccines 2022; 7:143. [PMID: 36357402 PMCID: PMC9649022 DOI: 10.1038/s41541-022-00562-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 10/17/2022] [Indexed: 11/12/2022] Open
Abstract
Whole cell vaccines are complex mixtures of antigens, immunogens, and sometimes adjuvants that can trigger potent and protective immune responses. In some instances, such as whole cell Bordetella pertussis vaccination, the immune response to vaccination extends beyond the pathogen the vaccine was intended for and contributes to protection against other clinically significant pathogens. In this study, we describe how B. pertussis whole cell vaccination protects mice against acute pneumonia caused by Pseudomonas aeruginosa. Using ELISA and western blot, we identified that B. pertussis whole cell vaccination induces production of antibodies that bind to lab-adapted and clinical strains of P. aeruginosa, regardless of immunization route or adjuvant used. The cross-reactive antigens were identified using immunoprecipitation, mass spectrometry, and subsequent immunoblotting. We determined that B. pertussis GroEL and OmpA present in the B. pertussis whole cell vaccine led to production of antibodies against P. aeruginosa GroEL and OprF, respectively. Finally, we showed that recombinant B. pertussis OmpA was sufficient to induce protection against P. aeruginosa acute murine pneumonia. This study highlights the potential for use of B. pertussis OmpA as a vaccine antigen for prevention of P. aeruginosa infection, and the potential of broadly protective antigens for vaccine development.
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Affiliation(s)
- Catherine B. Blackwood
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Margalida Mateu-Borrás
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Emel Sen-Kilic
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Gage M. Pyles
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Sarah Jo Miller
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Kelly L. Weaver
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - William T. Witt
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Annalisa B. Huckaby
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Jason Kang
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Courtney E. Chandler
- grid.411024.20000 0001 2175 4264University of Maryland, Baltimore Department of Microbial Pathogenesis, School of Dentistry, 650 W. Baltimore St., Baltimore, MD 21201 USA
| | - Robert K. Ernst
- grid.411024.20000 0001 2175 4264University of Maryland, Baltimore Department of Microbial Pathogenesis, School of Dentistry, 650 W. Baltimore St., Baltimore, MD 21201 USA
| | - F. Heath Damron
- grid.268154.c0000 0001 2156 6140West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV 26505 USA
| | - Mariette Barbier
- West Virginia University Vaccine Development Center, Department of Microbiology, Immunology and Cell Biology, 64 Medical Center Drive, Morgantown, WV, 26505, USA.
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4
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von Kügelgen A, van Dorst S, Alva V, Bharat TAM. A multidomain connector links the outer membrane and cell wall in phylogenetically deep-branching bacteria. Proc Natl Acad Sci U S A 2022; 119:e2203156119. [PMID: 35943982 PMCID: PMC9388160 DOI: 10.1073/pnas.2203156119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/24/2022] [Indexed: 01/30/2023] Open
Abstract
Deinococcus radiodurans is a phylogenetically deep-branching extremophilic bacterium that is remarkably tolerant to numerous environmental stresses, including large doses of ultraviolet (UV) radiation and extreme temperatures. It can even survive in outer space for several years. This endurance of D. radiodurans has been partly ascribed to its atypical cell envelope comprising an inner membrane, a large periplasmic space with a thick peptidoglycan (PG) layer, and an outer membrane (OM) covered by a surface layer (S-layer). Despite intense research, molecular principles governing envelope organization and OM stabilization are unclear in D. radiodurans and related bacteria. Here, we report a electron cryomicroscopy (cryo-EM) structure of the abundant D. radiodurans OM protein SlpA, showing how its C-terminal segment forms homotrimers of 30-stranded β-barrels in the OM, whereas its N-terminal segment forms long, homotrimeric coiled coils linking the OM to the PG layer via S-layer homology (SLH) domains. Furthermore, using protein structure prediction and sequence-based bioinformatic analysis, we show that SlpA-like putative OM-PG connector proteins are widespread in phylogenetically deep-branching Gram-negative bacteria. Finally, combining our atomic structures with fluorescence and electron microscopy of cell envelopes of wild-type and mutant bacterial strains, we report a model for the cell surface of D. radiodurans. Our results will have important implications for understanding the cell surface organization and hyperstability of D. radiodurans and related bacteria and the evolutionary transition between Gram-negative and Gram-positive bacteria.
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Affiliation(s)
- Andriko von Kügelgen
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Sofie van Dorst
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Vikram Alva
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen 72076, Germany
| | - Tanmay A. M. Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
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5
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Cell Envelope Stress Response in Pseudomonas aeruginosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:147-184. [DOI: 10.1007/978-3-031-08491-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Direct and Indirect Interactions Promote Complexes of the Lipoprotein LbcA, the CtpA Protease and Its Substrates, and Other Cell Wall Proteins in Pseudomonas aeruginosa. J Bacteriol 2021; 203:e0039321. [PMID: 34570626 DOI: 10.1128/jb.00393-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Pseudomonas aeruginosa lipoprotein LbcA was discovered because it copurified with and promoted the activity of CtpA, a carboxyl-terminal processing protease (CTP) required for type III secretion system function and virulence in a mouse model of acute pneumonia. In this study, we explored the role of LbcA by determining its effect on the proteome and its participation in protein complexes. lbcA- and ctpA-null mutations had strikingly similar effects on the proteome, suggesting that assisting CtpA might be the most impactful role of LbcA in the bacterial cell. Independent complexes containing LbcA and CtpA, or LbcA and a substrate, were isolated from P. aeruginosa cells, indicating that LbcA facilitates proteolysis by recruiting the protease and its substrates independently. An unbiased examination of proteins that copurified with LbcA revealed an enrichment for proteins associated with the cell wall. One of these copurification partners was found to be a new CtpA substrate and the first substrate that is not a peptidoglycan hydrolase. Many of the other LbcA copurification partners are known or predicted peptidoglycan hydrolases. However, some of these LbcA copurification partners were not cleaved by CtpA, and an in vitro assay revealed that while CtpA and all of its substrates bound to LbcA directly, these nonsubstrates did not. Subsequent experiments suggested that the nonsubstrates might copurify with LbcA by participating in multienzyme complexes containing LbcA-binding CtpA substrates. IMPORTANCE Carboxyl-terminal processing proteases (CTPs) are widely conserved and associated with the virulence of several bacteria, including CtpA in Pseudomonas aeruginosa. CtpA copurifies with the uncharacterized lipoprotein LbcA. This study shows that the most impactful role of LbcA might be to promote CtpA-dependent proteolysis and that it achieves this as a scaffold for CtpA and its substrates. It also reveals that LbcA copurification partners are enriched for cell wall-associated proteins, one of which is a novel CtpA substrate. Some of the LbcA copurification partners are not cleaved by CtpA but might copurify with LbcA because they participate in multienzyme complexes containing CtpA substrates. These findings are important because CTPs and their associated proteins affect peptidoglycan remodeling and virulence in multiple species.
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7
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Outer membrane permeability: Antimicrobials and diverse nutrients bypass porins in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2021; 118:2107644118. [PMID: 34326266 PMCID: PMC8346889 DOI: 10.1073/pnas.2107644118] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Novel antibiotics are urgently needed to resolve the current antimicrobial resistance crisis. For critical pathogens, drug entry through the cell envelope is one of the major challenges in the development of effective novel antibiotics. Envelope proteins forming water-filled channels, so-called porins, are commonly thought to be essential for entry of hydrophilic molecules, but we show here for the critical pathogen Pseudomonas aeruginosa that almost all antibiotics and diverse hydrophilic nutrients bypass porins and instead permeate directly through the outer membrane lipid bilayer. However, carboxylate groups hinder bilayer penetration, and Pseudomonas thus needs porins for efficient utilization of carboxylate-containing nutrients such as succinate. The major porin-independent entry route might open opportunities for facilitating drug delivery into bacteria. Gram-negative bacterial pathogens have an outer membrane that restricts entry of molecules into the cell. Water-filled protein channels in the outer membrane, so-called porins, facilitate nutrient uptake and are thought to enable antibiotic entry. Here, we determined the role of porins in a major pathogen, Pseudomonas aeruginosa, by constructing a strain lacking all 40 identifiable porins and 15 strains carrying only a single unique type of porin and characterizing these strains with NMR metabolomics and antimicrobial susceptibility assays. In contrast to common assumptions, all porins were dispensable for Pseudomonas growth in rich medium and consumption of diverse hydrophilic nutrients. However, preferred nutrients with two or more carboxylate groups such as succinate and citrate permeated poorly in the absence of porins. Porins provided efficient translocation pathways for these nutrients with broad and overlapping substrate selectivity while efficiently excluding all tested antibiotics except carbapenems, which partially entered through OprD. Porin-independent permeation of antibiotics through the outer-membrane lipid bilayer was hampered by carboxylate groups, consistent with our nutrient data. Together, these results challenge common assumptions about the role of porins by demonstrating porin-independent permeation of the outer-membrane lipid bilayer as a major pathway for nutrient and drug entry into the bacterial cell.
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8
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Mayeux G, Gayet L, Liguori L, Odier M, Martin DK, Cortès S, Schaack B, Lenormand JL. Cell-free expression of the outer membrane protein OprF of Pseudomonas aeruginosa for vaccine purposes. Life Sci Alliance 2021; 4:4/6/e202000958. [PMID: 33972378 PMCID: PMC8127326 DOI: 10.26508/lsa.202000958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 11/24/2022] Open
Abstract
Production of recombinant proteoliposomes containing OprF from P. aeruginosa promotes the active open conformation of the porin exposing native epitopes. These OprF proteoliposomes were used as vaccines to protect mice against a P. aeruginosa acute pulmonary infection model. Pseudomonas aeruginosa is the second-leading cause of nosocomial infections and pneumonia in hospitals. Because of its extraordinary capacity for developing resistance to antibiotics, treating infections by Pseudomonas is becoming a challenge, lengthening hospital stays, and increasing medical costs and mortality. The outer membrane protein OprF is a well-conserved and immunogenic porin playing an important role in quorum sensing and in biofilm formation. Here, we used a bacterial cell-free expression system to reconstitute OprF under its native forms in liposomes and we demonstrated that the resulting OprF proteoliposomes can be used as a fully functional recombinant vaccine against P. aeruginosa. Remarkably, we showed that our system promotes the folding of OprF into its active open oligomerized state as well as the formation of mega-pores. Our approach thus represents an easy and efficient way for producing bacterial membrane antigens exposing native epitopes for vaccine purposes.
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Affiliation(s)
- Géraldine Mayeux
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France
| | - Landry Gayet
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France
| | - Lavinia Liguori
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France.,Maison Familiale Rurale Moirans, Moirans, France
| | - Marine Odier
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France.,Catalent Pharma Solutions, Eberbach, Germany
| | - Donald K Martin
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France
| | | | - Béatrice Schaack
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France.,University Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Jean-Luc Lenormand
- TheREx and Synabi, University Grenoble Alpes, CNRS, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Institut Polytechnique (INP), Translational Innovation in Medicine and Complexity (TIMC), Grenoble, France
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9
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Paulsson M, Kragh KN, Su YC, Sandblad L, Singh B, Bjarnsholt T, Riesbeck K. Peptidoglycan-Binding Anchor Is a Pseudomonas aeruginosa OmpA Family Lipoprotein With Importance for Outer Membrane Vesicles, Biofilms, and the Periplasmic Shape. Front Microbiol 2021; 12:639582. [PMID: 33717034 PMCID: PMC7947798 DOI: 10.3389/fmicb.2021.639582] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/28/2021] [Indexed: 01/02/2023] Open
Abstract
The outer membrane protein A (OmpA) family contains an evolutionary conserved domain that links the outer membrane in Gram-negative bacteria to the semi-rigid peptidoglycan (PG) layer. The clinically significant pathogen Pseudomonas aeruginosa carries several OmpA family proteins (OprF, OprL, PA0833, and PA1048) that share the PG-binding domain. These proteins are important for cell morphology, membrane stability, and biofilm and outer membrane vesicle (OMV) formation. In addition to other OmpAs, in silico analysis revealed that the putative outer membrane protein (OMP) with gene locus PA1041 is a lipoprotein with an OmpA domain and, hence, is a potential virulence factor. This study aimed to evaluate PA1041 as a PG-binding protein and describe its effect on the phenotype. Clinical strains were confirmed to contain the lipoprotein resulting from PA1041 expression with Western blot, and PG binding was verified in enzyme-linked immunosorbent assay (ELISA). By using a Sepharose bead-based ELISA, we found that the lipoprotein binds to meso-diaminopimelic acid (mDAP), an amino acid in the pentapeptide portion of PGs. The reference strain PAO1 and the corresponding transposon mutant PW2884 devoid of the lipoprotein were examined for phenotypic changes. Transmission electron microscopy revealed enlarged periplasm spaces near the cellular poles in the mutant. In addition, we observed an increased release of OMV, which could be confirmed by nanoparticle tracking analysis. Importantly, mutants without the lipoprotein produced a thick, but loose and unorganized, biofilm in flow cells. In conclusion, the lipoprotein from gene locus PA1041 tethers the outer membrane to the PG layer, and mutants are viable, but display severe phenotypic changes including disordered biofilm formation. Based upon the phenotype of the P. aeruginosa PW2884 mutant and the function of the protein, we designate the lipoprotein with locus tag PA1041 as “peptidoglycan-binding anchor” (Pba).
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Affiliation(s)
- Magnus Paulsson
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden.,Division for Infectious Diseases, Skåne University Hospital, Lund, Sweden
| | - Kasper Nørskov Kragh
- Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Yu-Ching Su
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Linda Sandblad
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Birendra Singh
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Thomas Bjarnsholt
- Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kristian Riesbeck
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
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10
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Pushing beyond the Envelope: the Potential Roles of OprF in Pseudomonas aeruginosa Biofilm Formation and Pathogenicity. J Bacteriol 2019; 201:JB.00050-19. [PMID: 31010902 DOI: 10.1128/jb.00050-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The ability of Pseudomonas aeruginosa to form biofilms, which are communities of cells encased in a self-produced extracellular matrix, protects the cells from antibiotics and the host immune response. While some biofilm matrix components, such as exopolysaccharides and extracellular DNA, are relatively well characterized, the extracellular matrix proteins remain understudied. Multiple proteomic analyses of the P. aeruginosa soluble biofilm matrix and outer membrane vesicles, which are a component of the matrix, have identified OprF as an abundant matrix protein. To date, the few reports on the effects of oprF mutations on biofilm formation are conflicting, and little is known about the potential role of OprF in the biofilm matrix. The majority of OprF studies focus on the protein as a cell-associated porin. As a component of the outer membrane, OprF assumes dual conformations and is involved in solute transport, as well as cell envelope integrity. Here, we review the current literature on OprF in P. aeruginosa, discussing how the structure and function of the cell-associated and matrix-associated protein may affect biofilm formation and pathogenesis in order to inform future research on this understudied matrix protein.
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11
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Song F, Wang H, Sauer K, Ren D. Cyclic-di-GMP and oprF Are Involved in the Response of Pseudomonas aeruginosa to Substrate Material Stiffness during Attachment on Polydimethylsiloxane (PDMS). Front Microbiol 2018; 9:110. [PMID: 29449837 PMCID: PMC5799285 DOI: 10.3389/fmicb.2018.00110] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/17/2018] [Indexed: 12/29/2022] Open
Abstract
Recently, we reported that the stiffness of poly(dimethylsiloxane) (PDMS) affects the attachment of Pseudomonas aeruginosa, and the morphology and antibiotic susceptibility of attached cells. To further understand how P. aeruginosa responses to material stiffness during attachment, the wild-type P. aeruginosa PAO1 and several isogenic mutants were characterized for their attachment on soft and stiff PDMS. Compared to the wild-type strain, mutation of the oprF gene abolished the differences in attachment, growth, and size of attached cells between soft and stiff PDMS surfaces. These defects were rescued by genetic complementation of oprF. We also found that the wild-type P. aeruginosa PAO1 cells attached on soft (40:1) PDMS have higher level of intracellular cyclic dimeric guanosine monophosphate (c-di-GMP), a key regulator of biofilm formation, compared to those on stiff (5:1) PDMS surfaces. Consistently, the mutants of fleQ and wspF, which have similar high-level c-di-GMP as the oprF mutant, exhibited defects in response to PDMS stiffness during attachment. Collectively, the results from this study suggest that P. aeruginosa can sense the stiffness of substrate material during attachment and respond to such mechanical cues by adjusting c-di-GMP level and thus the following biofilm formation. Further understanding of the related genes and pathways will provide new insights into bacterial mechanosensing and help develop better antifouling materials.
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Affiliation(s)
- Fangchao Song
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, United States.,Syracuse Biomaterials Institute, Syracuse, NY, United States
| | - Hao Wang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, United States.,Syracuse Biomaterials Institute, Syracuse, NY, United States
| | - Karin Sauer
- Department of Biological Science, Binghamton University, Binghamton, NY, United States
| | - Dacheng Ren
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, United States.,Syracuse Biomaterials Institute, Syracuse, NY, United States.,Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, United States.,Department of Biology, Syracuse University, Syracuse, NY, United States
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12
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Chevalier S, Bouffartigues E, Bodilis J, Maillot O, Lesouhaitier O, Feuilloley MGJ, Orange N, Dufour A, Cornelis P. Structure, function and regulation of Pseudomonas aeruginosa porins. FEMS Microbiol Rev 2017; 41:698-722. [PMID: 28981745 DOI: 10.1093/femsre/fux020] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/24/2017] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium belonging to the γ-proteobacteria. Like other members of the Pseudomonas genus, it is known for its metabolic versatility and its ability to colonize a wide range of ecological niches, such as rhizosphere, water environments and animal hosts, including humans where it can cause severe infections. Another particularity of P. aeruginosa is its high intrinsic resistance to antiseptics and antibiotics, which is partly due to its low outer membrane permeability. In contrast to Enterobacteria, pseudomonads do not possess general diffusion porins in their outer membrane, but rather express specific channel proteins for the uptake of different nutrients. The major outer membrane 'porin', OprF, has been extensively investigated, and displays structural, adhesion and signaling functions while its role in the diffusion of nutrients is still under discussion. Other porins include OprB and OprB2 for the diffusion of glucose, the two small outer membrane proteins OprG and OprH, and the two porins involved in phosphate/pyrophosphate uptake, OprP and OprO. The remaining nineteen porins belong to the so-called OprD (Occ) family, which is further split into two subfamilies termed OccD (8 members) and OccK (11 members). In the past years, a large amount of information concerning the structure, function and regulation of these porins has been published, justifying why an updated review is timely.
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Affiliation(s)
- Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Emeline Bouffartigues
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Josselin Bodilis
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Olivier Maillot
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Marc G J Feuilloley
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Nicole Orange
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
| | - Alain Dufour
- IUEM, Laboratoire de Biotechnologie et Chimie Marines EA 3884, Université de Bretagne-Sud (UEB), 56321 Lorient, France
| | - Pierre Cornelis
- Laboratory of Microbiology Signals and Microenvironment LMSM EA 4312, University of Rouen, Normandy University, 27000 Evreux, France
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13
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CmpX Affects Virulence in Pseudomonas aeruginosa Through the Gac/Rsm Signaling Pathway and by Modulating c-di-GMP Levels. J Membr Biol 2017; 251:35-49. [DOI: 10.1007/s00232-017-9994-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/12/2017] [Indexed: 10/18/2022]
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14
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Chanda W, Joseph TP, Padhiar AA, Guo X, Min L, Wang W, Lolokote S, Ning A, Cao J, Huang M, Zhong M. Combined effect of linolenic acid and tobramycin on Pseudomonas aeruginosa biofilm formation and quorum sensing. Exp Ther Med 2017; 14:4328-4338. [PMID: 29104645 PMCID: PMC5658730 DOI: 10.3892/etm.2017.5110] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/22/2017] [Indexed: 12/28/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous Gram negative opportunistic pathogen capable of causing severe nosocomial infections in humans, and tobramycin is currently used to treat P. aeruginosa associated lung infections. Quorum sensing regulates biofilm formation which allows the bacterium to result in fatal infections forcing clinicians to extensively use antibiotics to manage its infections leading to emerging multiple drug resistant strains. As a result, tobramycin is also becoming resistant. Despite extensive studies on drug discovery to alleviate microbial drug resistance, the continued microbial evolution has forced researchers to focus on screening various phytochemicals and dietary compounds for antimicrobial potential. Linolenic acid (LNA) is an essential fatty acid that possesses antimicrobial actions on various microorganisms. It was hypothesized that LNA may affect the formation of biofilm on P. aeruginosa and improve the potency of tobramycin. The present study demonstrated that LNA interfered with cell-to-cell communication and reduced virulence factor production. It further enhanced the potency of tobramycin and synergistically inhibited biofilm formation through P. aeruginosa quorum sensing systems. Therefore, LNA may be considered as a potential agent for adjunctive therapy and its utilization may decrease tobramycin concentration in combined treatment thereby reducing aminoglycoside adverse effects.
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Affiliation(s)
- Warren Chanda
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Thomson Patrick Joseph
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Arshad Ahmed Padhiar
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Xuefang Guo
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Liu Min
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Wendong Wang
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Sainyugu Lolokote
- Department of Epidemiology and Biostatistics, School of Public Health, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Anhong Ning
- Laboratory of Pathogen Biology, Experimental Teaching Center for Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Jing Cao
- Laboratory of Pathogen Biology, Experimental Teaching Center for Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Min Huang
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
| | - Mintao Zhong
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, Liaoning 116044 P.R. China
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15
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Tchoupa AK, Lichtenegger S, Reidl J, Hauck CR. Outer membrane protein P1 is the CEACAM-binding adhesin of Haemophilus influenzae. Mol Microbiol 2015; 98:440-55. [PMID: 26179342 DOI: 10.1111/mmi.13134] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2015] [Indexed: 12/01/2022]
Abstract
Haemophilus influenzae is a Gram-negative pathogen colonizing the upper respiratory tract mucosa. H. influenzae is one of several human-restricted bacteria, which bind to carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) on the epithelium leading to bacterial uptake by the eukaryotic cells. Adhesion to CEACAMs is thought to be mediated by the H. influenzae outer membrane protein (OMP) P5. However, CEACAMs still bound to H. influenzae lacking OMP P5 expression, and soluble CEACAM receptor ectodomains failed to bind to OMP P5, when heterologously expressed in Escherichia coli. Screening of a panel of H. influenzae OMP mutants revealed that lack of OMP P1 completely abrogated CEACAM binding and supressed CEACAM-mediated engulfment of H. influenzae by epithelial cells. Moreover, ectopic expression of OMP P1 in E. coli was sufficient to induce CEACAM binding and to promote attachment to and internalization into CEACAM-expressing cells. Interestingly, OMP P1 selectively recognizes human CEACAMs, but not homologs from other mammals and this binding preference is preserved upon expression in E. coli. Together, our data identify OMP P1 as the bona fide CEACAM-binding invasin of H. influenzae. This is the first report providing evidence for an involvement of the major OMP P1 of H. influenzae in pathogenesis.
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Affiliation(s)
| | | | - Joachim Reidl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Christof R Hauck
- Lehrstuhl für Zellbiologie, Universität Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology, Universität Konstanz, Konstanz, Germany
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16
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Quigley KJ, Reynolds CJ, Goudet A, Raynsford EJ, Sergeant R, Quigley A, Worgall S, Bilton D, Wilson R, Loebinger MR, Maillere B, Altmann DM, Boyton RJ. Chronic Infection by Mucoid Pseudomonas aeruginosa Associated with Dysregulation in T-Cell Immunity to Outer Membrane Porin F. Am J Respir Crit Care Med 2015; 191:1250-64. [PMID: 25789411 DOI: 10.1164/rccm.201411-1995oc] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Pseudomonas aeruginosa (PA) is an environmental pathogen that commonly infects individuals with cystic fibrosis (CF) and non-CF bronchiectasis, impacting morbidity and mortality. To understand the pathobiology of interactions between the bacterium and host adaptive immunity and to inform rational vaccine design, it is important to understand the adaptive immune correlates of disease. OBJECTIVES To characterize T-cell immunity to the PA antigen outer membrane porin F (OprF) by analyzing immunodominant epitopes in relation to infection status. METHODS Patients with non-CF bronchiectasis were stratified by frequency of PA isolation. T-cell IFN-γ immunity to OprF and its immunodominant epitopes was characterized. Patterns of human leukocyte antigen (HLA) restriction of immunodominant epitopes were defined using HLA class II transgenic mice. Immunity was characterized with respect to cytokine and chemokine secretion, antibody response, and T-cell activation transcripts. MEASUREMENTS AND MAIN RESULTS Patients were stratified according to whether PA was never, sometimes (<50%), or frequently (≥50%) isolated from sputum. Patients with frequent PA sputum-positive isolates were more likely to be infected by mucoid PA, and they showed a narrow T-cell epitope response and a relative reduction in Th1 polarizing transcription factors but enhanced immunity with respect to antibody production, innate cytokines, and chemokines. CONCLUSIONS We have defined the immunodominant, HLA-restricted T-cell epitopes of OprF. Our observation that chronic infection is associated with a response of narrowed specificity, despite strong innate and antibody immunity, may help to explain susceptibility in these individuals and pave the way for better vaccine design to achieve protective immunity.
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Affiliation(s)
- Kathryn J Quigley
- 1 Lung Immunology Group, Infectious Diseases and Immunity, Department of Medicine, Medical Research Council and Asthma United Kingdom Centre in Allergic Mechanisms of Asthma, Centre for Respiratory Infection, Hammersmith Hospital, Imperial College, London, United Kingdom
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17
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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] [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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18
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Probing the protein interaction network of Pseudomonas aeruginosa cells by chemical cross-linking mass spectrometry. Structure 2015; 23:762-73. [PMID: 25800553 DOI: 10.1016/j.str.2015.01.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/13/2015] [Accepted: 01/23/2015] [Indexed: 11/22/2022]
Abstract
In pathogenic Gram-negative bacteria, interactions among membrane proteins are key mediators of host cell attachment, invasion, pathogenesis, and antibiotic resistance. Membrane protein interactions are highly dependent upon local properties and environment, warranting direct measurements on native protein complex structures as they exist in cells. Here we apply in vivo chemical cross-linking mass spectrometry, to reveal the first large-scale protein interaction network in Pseudomonas aeruginosa, an opportunistic human pathogen, by covalently linking interacting protein partners, thereby fixing protein complexes in vivo. A total of 626 cross-linked peptide pairs, including previously unknown interactions of many membrane proteins, are reported. These pairs not only define the existence of these interactions in cells but also provide linkage constraints for complex structure predictions. Structures of three membrane proteins, namely, SecD-SecF, OprF, and OprI are predicted using in vivo cross-linked sites. These findings improve understanding of membrane protein interactions and structures in cells.
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19
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Ishida H, Garcia-Herrero A, Vogel HJ. The periplasmic domain of Escherichia coli outer membrane protein A can undergo a localized temperature dependent structural transition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3014-24. [PMID: 25135663 DOI: 10.1016/j.bbamem.2014.08.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 01/21/2023]
Abstract
Gram-negative bacteria such as Escherichia coli are surrounded by two membranes with a thin peptidoglycan (PG)-layer located in between them in the periplasmic space. The outer membrane protein A (OmpA) is a 325-residue protein and it is the major protein component of the outer membrane of E. coli. Previous structure determinations have focused on the N-terminal fragment (residues 1-171) of OmpA, which forms an eight stranded transmembrane β-barrel in the outer membrane. Consequently it was suggested that OmpA is composed of two independently folded domains in which the N-terminal β-barrel traverses the outer membrane and the C-terminal domain (residues 180-325) adopts a folded structure in the periplasmic space. However, some reports have proposed that full-length OmpA can instead refold in a temperature dependent manner into a single domain forming a larger transmembrane pore. Here, we have determined the NMR solution structure of the C-terminal periplasmic domain of E. coli OmpA (OmpA(180-325)). Our structure reveals that the C-terminal domain folds independently into a stable globular structure that is homologous to the previously reported PG-associated domain of Neisseria meningitides RmpM. Our results lend credence to the two domain structure model and a PG-binding function for OmpA, and we could indeed localize the PG-binding site on the protein through NMR chemical shift perturbation experiments. On the other hand, we found no evidence for binding of OmpA(180-325) with the TonB protein. In addition, we have also expressed and purified full-length OmpA (OmpA(1-325)) to study the structure of the full-length protein in micelles and nanodiscs by NMR spectroscopy. In both membrane mimetic environments, the recombinant OmpA maintains its two domain structure that is connected through a flexible linker. A series of temperature-dependent HSQC experiments and relaxation dispersion NMR experiments detected structural destabilization in the bulge region of the periplasmic domain of OmpA above physiological temperatures, which may induce dimerization and play a role in triggering the previously reported larger pore formation.
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Affiliation(s)
- Hiroaki Ishida
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Alicia Garcia-Herrero
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Hans J Vogel
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
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20
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Hemamalini R, Khare S. A proteomic approach to understand the role of the outer membrane porins in the organic solvent-tolerance of Pseudomonas aeruginosa PseA. PLoS One 2014; 9:e103788. [PMID: 25089526 PMCID: PMC4121210 DOI: 10.1371/journal.pone.0103788] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/07/2014] [Indexed: 01/09/2023] Open
Abstract
Solvent-tolerant microbes have the unique ability to thrive in presence of organic solvents. The present study describes the effect of increasing hydrophobicity (log Pow values) of organic solvents on the outer membrane proteome of the solvent-tolerant Pseudomonas aeruginosa PseA cells. The cells were grown in a medium containing 33% (v/v) alkanes of increasing log Pow values. The outer membrane proteins were extracted by alkaline extraction from the late log phase cells and changes in the protein expression were studied by 2-D gel electrophoresis. Seven protein spots showed significant differential expression in the solvent exposed cells. The tryptic digest of the differentially regulated proteins were identified by LC-ESI MS/MS. The identity of these proteins matched with porins OprD, OprE, OprF, OprH, Opr86, LPS assembly protein and A-type flagellin. The reported pI values of these proteins were in the range of 4.94-8.67 and the molecular weights were in the range of 19.5-104.5 kDa. The results suggest significant down-regulation of the A-type flagellin, OprF and OprD and up-regulation of OprE, OprH, Opr86 and LPS assembly protein in presence of organic solvents. OprF and OprD are implicated in antibiotic uptake and outer membrane stability, whereas A-type flagellin confers motility and chemotaxis. Up-regulated OprE is an anaerobically-induced porin while Opr86 is responsible for transport of small molecules and assembly of the outer membrane proteins. Differential regulation of the above porins clearly indicates their role in adaptation to solvent exposure.
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Affiliation(s)
- R. Hemamalini
- Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology, Delhi, New Delhi, India
| | - Sunil Khare
- Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology, Delhi, New Delhi, India
- * E-mail:
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21
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Structural changes and differentially expressed genes in Pseudomonas aeruginosa exposed to meropenem-ciprofloxacin combination. Antimicrob Agents Chemother 2014; 58:3957-67. [PMID: 24798291 DOI: 10.1128/aac.02584-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The effect of a meropenem-ciprofloxacin combination (MCC) on the susceptibility of multidrug-resistant (MDR) Pseudomonas aeruginosa (MRPA) clinical isolates was determined using checkerboard and time-kill curve techniques. Structural changes and differential gene expression that resulted from the synergistic action of the MCC against one of the P. aeruginosa isolates (1071-MRPA]) were evaluated using electron microscopy and representational difference analysis (RDA), respectively. The differentially expressed, SOS response-associated, and resistance-associated genes in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC were monitored by quantitative PCR. The MCC was synergistic against 25% and 40.6% of MDR P. aeruginosa isolates as shown by the checkerboard and time-kill curves, respectively. The morphological and structural changes that resulted from the synergistic action of the MCC against 1071-MRPA were a summation of the effects observed with each antimicrobial alone. One exception included outer membrane vesicles, which were seen in a greater amount upon ciprofloxacin exposure but were significantly inhibited upon MCC exposure. Cell wall- and DNA repair-associated genes were differentially expressed in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC. However, some of the RDA-detected, resistance-associated, and SOS response-associated genes were expressed at significantly lower levels in 1071-MRPA exposed to the MCC. The MCC may be an alternative for the treatment of MDR P. aeruginosa. The effect of this antimicrobial combination may be not only the result of a summation of the effects of meropenem and ciprofloxacin but also a result of differential action that likely inhibits protective mechanisms in the bacteria.
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22
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Emergence of carbapenem resistance due to the novel insertion sequence ISPa8 in Pseudomonas aeruginosa. PLoS One 2014; 9:e91299. [PMID: 24614163 PMCID: PMC3948848 DOI: 10.1371/journal.pone.0091299] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 02/09/2014] [Indexed: 11/19/2022] Open
Abstract
Chronic lung infections due to the persistence of Pseudomonas aeruginosa in cystic fibrosis patients are typically associated with the emergence of antibiotic resistance. The purpose of this study was to investigate the mechanisms responsible for the emergence of carbapenem resistance when a clinical isolate of P. aeruginosa collected from a patient with cystic fibrosis was challenged with meropenem. Nine carbapenem-resistant mutants were selected with subinhibitory concentrations of meropenem from a clinical isolate of P. aeruginosa and characterized for carbapenem resistance. Increased carbapenem MICs were associated with the identification of the novel insertion sequence ISPa8 within oprD or its promoter region in all the mutants. The position of ISPa8 was different for each of the mutants evaluated. In addition, Southern blot analyses identified multiple copies of ISPa8 within the genomes of the mutants and their parent isolate. These data demonstrate that transposition of IS elements within the Pseudomonas genome can influence antibiotic susceptibility. Understanding the selective pressures associated with the emergence of antibiotic resistance is critical for the judicious use of antimicrobial chemotherapy and the successful treatment of bacterial infections.
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23
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Gicquel G, Bouffartigues E, Bains M, Oxaran V, Rosay T, Lesouhaitier O, Connil N, Bazire A, Maillot O, Bénard M, Cornelis P, Hancock REW, Dufour A, Feuilloley MGJ, Orange N, Déziel E, Chevalier S. The extra-cytoplasmic function sigma factor sigX modulates biofilm and virulence-related properties in Pseudomonas aeruginosa. PLoS One 2013; 8:e80407. [PMID: 24260387 PMCID: PMC3832394 DOI: 10.1371/journal.pone.0080407] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 10/02/2013] [Indexed: 11/23/2022] Open
Abstract
SigX, one of the 19 extra-cytoplasmic function sigma factors of P. aeruginosa, was only known to be involved in transcription of the gene encoding the major outer membrane protein OprF. We conducted a comparative transcriptomic study between the wildtype H103 strain and its sigX mutant PAOSX, which revealed a total of 307 differentially expressed genes that differed by more than 2 fold. Most dysregulated genes belonged to six functional classes, including the “chaperones and heat shock proteins”, “antibiotic resistance and susceptibility”, “energy metabolism”, “protein secretion/export apparatus”, and “secreted factors”, and “motility and attachment” classes. In this latter class, the large majority of the affected genes were down-regulated in the sigX mutant. In agreement with the array data, the sigX mutant was shown to demonstrate substantially reduced motility, attachment to biotic and abiotic surfaces, and biofilm formation. In addition, virulence towards the nematode Caenorhabditis elegans was reduced in the sigX mutant, suggesting that SigX is involved in virulence-related phenotypes.
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Affiliation(s)
- Gwendoline Gicquel
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Emeline Bouffartigues
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Manjeet Bains
- Centre for Microbal Diseases and Immunity Research, University of British Columbia, Vancouver, Canada
| | - Virginie Oxaran
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Thibaut Rosay
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Olivier Lesouhaitier
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Nathalie Connil
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Alexis Bazire
- IUEM, Université de Bretagne-Sud (UEB), Laboratoire de Biotechnologie et Chimie Marines EA 3884, Lorient, France
| | - Olivier Maillot
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Magalie Bénard
- Cell Imaging Platform of Normandy (PRIMACEN), IRIB, Faculty of Sciences, University of Rouen, Mont-Saint-Aignan, France
| | - Pierre Cornelis
- Department of Bioengineering Sciences, Research group Microbiology, VIB Department of Structural Biology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Robert E. W. Hancock
- Centre for Microbal Diseases and Immunity Research, University of British Columbia, Vancouver, Canada
| | - Alain Dufour
- IUEM, Université de Bretagne-Sud (UEB), Laboratoire de Biotechnologie et Chimie Marines EA 3884, Lorient, France
| | - Marc G. J. Feuilloley
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Nicole Orange
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
| | - Eric Déziel
- INRS-Institut Armand-Frappier, Laval, Québec, Canada
| | - Sylvie Chevalier
- Normandie Université, Université de Rouen, Laboratoire de Microbiologie Signaux et Micro-environnement EA 4312, Evreux, France
- * E-mail:
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24
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Duchesne R, Bouffartigues E, Oxaran V, Maillot O, Bénard M, Feuilloley MGJ, Orange N, Chevalier S. A proteomic approach of SigX function in Pseudomonas aeruginosa outer membrane composition. J Proteomics 2013; 94:451-9. [PMID: 24332064 DOI: 10.1016/j.jprot.2013.10.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/29/2013] [Accepted: 10/17/2013] [Indexed: 12/22/2022]
Abstract
UNLABELLED SigX is one of the 19 extracytoplasmic function sigma factors that have been predicted in the human opportunistic pathogen Pseudomonas aeruginosa genome. SigX is involved in the transcription of oprF, encoding the major outer membrane protein OprF, a pleiotropic porin that contributes to the maintaining of the wall structure, and is essential to P. aeruginosa virulence. This study aimed to get further insights into the functions of SigX. We performed here an outer membrane subproteome of a sigX mutant. Proteomic investigations revealed lower production of 8 porins among which 4 gated channels involved in iron or hem uptake, OprF, and the three substrate-specific proteins OprD, OprQ and OprE. On the other side, the glucose-specific porin OprB and the lipid A 3-O-deacylase that is involved in LPS modification were up-regulated. Our results indicate that SigX may be involved in the control and/or regulation of the outer membrane composition. BIOLOGICAL SIGNIFICANCE A proteomic approach was used herein to get further insights into SigX functions in P. aeruginosa. The data presented here suggest that SigX is involved in the outer membrane protein composition, and could be linked to a regulatory network involved in OM homeostasis.
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Affiliation(s)
- Rachel Duchesne
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Emeline Bouffartigues
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Virginie Oxaran
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Olivier Maillot
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Magalie Bénard
- Cell Imaging Platform of Normandy (PRIMACEN), IRIB, Faculty of Sciences, University of Rouen, Mont-Saint-Aignan F-76821, France
| | - Marc G J Feuilloley
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Nicole Orange
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France
| | - Sylvie Chevalier
- Laboratory of Microbiology Signal and Microenvironment (LMSM) EA 4312, University of Rouen, GRRs SeSa, IRIB, Evreux F-27000, France.
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25
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Matthijs S, Coorevits A, Gebrekidan TT, Tricot C, Wauven CV, Pirnay JP, De Vos P, Cornelis P. Evaluation of oprI and oprL genes as molecular markers for the genus Pseudomonas and their use in studying the biodiversity of a small Belgian River. Res Microbiol 2013; 164:254-61. [DOI: 10.1016/j.resmic.2012.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 11/26/2012] [Indexed: 10/27/2022]
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26
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Thakur PB, Vaughn-Diaz VL, Greenwald JW, Gross DC. Characterization of five ECF sigma factors in the genome of Pseudomonas syringae pv. syringae B728a. PLoS One 2013; 8:e58846. [PMID: 23516563 PMCID: PMC3597554 DOI: 10.1371/journal.pone.0058846] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/07/2013] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas syringae pv. syringae B728a, a bacterial pathogen of bean, utilizes large surface populations and extracellular signaling to initiate a fundamental change from an epiphytic to a pathogenic lifestyle. Extracytoplasmic function (ECF) sigma (σ) factors serve as important regulatory factors in responding to various environmental signals. Bioinformatic analysis of the B728a genome revealed 10 ECF sigma factors. This study analyzed deletion mutants of five previously uncharacterized ECF sigma factor genes in B728a, including three FecI-type ECF sigma factors (ECF5, ECF6, and ECF7) and two ECF sigma factors placed in groups ECF11 and ECF18. Transcriptional profiling by qRT-PCR analysis of ECF sigma factor mutants was used to measure expression of their associated anti-sigma and outer membrane receptor proteins, and expression of genes associated with production of extracellular polysaccharides, fimbriae, glycine betaine and syringomycin. Notably, the B728aΔecf7 mutant displayed reduced swarming and had decreased expression of CupC fimbrial genes. Growth and pathogenicity assays, using a susceptible bean host, revealed that none of the tested sigma factor genes are required for in planta growth and lesion formation.
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Affiliation(s)
- Poulami Basu Thakur
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
| | - Vanessa L. Vaughn-Diaz
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
| | - Jessica W. Greenwald
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
| | - Dennis C. Gross
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
- * E-mail: .
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Roberts AEL, Maddocks SE, Cooper RA. Manuka honey is bactericidal against Pseudomonas aeruginosa and results in differential expression of oprF and algD. MICROBIOLOGY-SGM 2012; 158:3005-3013. [PMID: 23082035 DOI: 10.1099/mic.0.062794-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The presence of Pseudomonas aeruginosa in cutaneous wounds is of clinical significance and can lead to persistent infections. Manuka honey has gained ground in clinical settings due to its effective therapeutic action and broad spectrum of antibacterial activity. In this study, the effect of manuka honey on P. aeruginosa was investigated using MIC, MBC, growth kinetics, confocal microscopy, atomic force microscopy and real-time PCR. A bactericidal mode of action for manuka honey against P. aeruginosa was deduced (12 %, w/v, MIC; 16 %, w/v, MBC) and confirmed by confocal and atomic force microscopy, which showed extensive cell lysis after 60 min exposure to inhibitory concentrations of manuka honey. The inability of honey-treated cells to form microcolonies was demonstrated and investigated using Q-PCR for three key microcolony-forming genes: algD, lasR and oprF. The expression of algD increased 16-fold whereas oprF expression decreased 10-fold following honey treatment; lasR expression remained unaltered. These findings confirm that manuka honey is effective at inducing cell lysis and identify two targets, at the genetic level, that might be involved in this process.
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Affiliation(s)
- Aled E L Roberts
- Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK
| | - Sarah E Maddocks
- Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK
| | - Rose A Cooper
- Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK
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28
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Ritter A, Com E, Bazire A, Goncalves MDS, Delage L, Pennec GL, Pineau C, Dreanno C, Compère C, Dufour A. Proteomic studies highlight outer-membrane proteins related to biofilm development in the marine bacterium Pseudoalteromonas sp. D41. Proteomics 2012; 12:3180-92. [DOI: 10.1002/pmic.201100644] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 07/27/2012] [Accepted: 08/04/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Andrés Ritter
- Laboratoire de Biotechnologie et Chimie Marines; Université de Bretagne-Sud (UEB), IUEM; Lorient France
- IFREMER; Service Interfaces et Capteurs; Plouzané France
| | - Emmanuelle Com
- Proteomics Core Facility BIOGENOUEST; IRSET - Inserm U1085; Campus de Beaulieu; Rennes France
| | - Alexis Bazire
- Laboratoire de Biotechnologie et Chimie Marines; Université de Bretagne-Sud (UEB), IUEM; Lorient France
| | | | - Ludovic Delage
- CNRS, UPMC; UMR 7139 Végétaux Marins et Biomolécules; Station Biologique; Roscoff France
| | - Gaël Le Pennec
- Laboratoire de Biotechnologie et Chimie Marines; Université de Bretagne-Sud (UEB), IUEM; Lorient France
| | - Charles Pineau
- Proteomics Core Facility BIOGENOUEST; IRSET - Inserm U1085; Campus de Beaulieu; Rennes France
| | | | | | - Alain Dufour
- Laboratoire de Biotechnologie et Chimie Marines; Université de Bretagne-Sud (UEB), IUEM; Lorient France
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29
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Funken H, Bartels KM, Wilhelm S, Brocker M, Bott M, Bains M, Hancock REW, Rosenau F, Jaeger KE. Specific association of lectin LecB with the surface of Pseudomonas aeruginosa: role of outer membrane protein OprF. PLoS One 2012; 7:e46857. [PMID: 23056489 PMCID: PMC3466170 DOI: 10.1371/journal.pone.0046857] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 09/06/2012] [Indexed: 01/31/2023] Open
Abstract
The fucose binding lectin LecB affects biofilm formation and is involved in pathogenicity of Pseudomonas aeruginosa. LecB resides in the outer membrane and can be released specifically by treatment of an outer membrane fraction with fucose suggesting that it binds to specific ligands. Here, we report that LecB binds to the outer membrane protein OprF. In an OprF-deficient P. aeruginosa mutant, LecB is no longer detectable in the membrane but instead in the culture supernatant indicating a specific interaction between LecB and OprF.
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Affiliation(s)
- Horst Funken
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich, Germany
| | - Kai-Malte Bartels
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich, Germany
| | - Susanne Wilhelm
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich, Germany
| | - Melanie Brocker
- Institute of Bio- and Geoscience 1, Forschungszentrum Jülich, Juelich, Germany
| | - Michael Bott
- Institute of Bio- and Geoscience 1, Forschungszentrum Jülich, Juelich, Germany
| | - Manjeet Bains
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Robert E. W. Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Frank Rosenau
- Institute of Pharmaceutical Biotechnology, Ulm-University, Ulm, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich, Germany
- * E-mail:
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30
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Transcription of the oprF gene of Pseudomonas aeruginosa is dependent mainly on the SigX sigma factor and is sucrose induced. J Bacteriol 2012; 194:4301-11. [PMID: 22685281 DOI: 10.1128/jb.00509-12] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The OprF porin is the major outer membrane protein of Pseudomonas aeruginosa. OprF is involved in several crucial functions, including cell structure, outer membrane permeability, environmental sensing, and virulence. The oprF gene is preceded by the sigX gene, which encodes the poorly studied extracytoplasmic function (ECF) sigma factor SigX. Three oprF promoters were previously identified. Two intertwined promoters dependent on σ(70) and SigX are located in the sigX-oprF intergenic region, whereas a promoter dependent on the ECF AlgU lies within the sigX gene. An additional promoter was found in the cmpX-sigX intergenic region. In this study, we dissected the contribution of each promoter region and of each sigma factor to oprF transcription using transcriptional fusions. In Luria-Bertani (LB) medium, the oprF-proximal region (sigX-oprF intergenic region) accounted for about 80% of the oprF transcription, whereas the AlgU-dependent promoter had marginal activity. Using the sigX mutant PAOSX, we observed that the SigX-dependent promoter was largely predominant over the σ(70)-dependent promoter. oprF transcription was increased in response to low NaCl or high sucrose concentrations, and this induced transcription was strongly impaired in the absence of SigX. The lack of OprF itself increased oprF transcription. Since these conditions led to cell wall alterations, oprF transcription could be activated by signals triggered by perturbation of the cell envelope.
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31
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Fito-Boncompte L, Chapalain A, Bouffartigues E, Chaker H, Lesouhaitier O, Gicquel G, Bazire A, Madi A, Connil N, Véron W, Taupin L, Toussaint B, Cornelis P, Wei Q, Shioya K, Déziel E, Feuilloley MGJ, Orange N, Dufour A, Chevalier S. Full virulence of Pseudomonas aeruginosa requires OprF. Infect Immun 2011; 79:1176-86. [PMID: 21189321 PMCID: PMC3067511 DOI: 10.1128/iai.00850-10] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 09/10/2010] [Accepted: 12/02/2010] [Indexed: 01/26/2023] Open
Abstract
OprF is a general outer membrane porin of Pseudomonas aeruginosa, a well-known human opportunistic pathogen associated with severe hospital-acquired sepsis and chronic lung infections of cystic fibrosis patients. A multiphenotypic approach, based on the comparative study of a wild-type strain of P. aeruginosa, its isogenic oprF mutant, and an oprF-complemented strain, showed that OprF is required for P. aeruginosa virulence. The absence of OprF results in impaired adhesion to animal cells, secretion of ExoT and ExoS toxins through the type III secretion system (T3SS), and production of the quorum-sensing-dependent virulence factors pyocyanin, elastase, lectin PA-1L, and exotoxin A. Accordingly, in the oprF mutant, production of the signal molecules N-(3-oxododecanoyl)-l-homoserine lactone and N-butanoyl-l-homoserine lactone was found to be reduced and delayed, respectively. Pseudomonas quinolone signal (PQS) production was decreased, while its precursor, 4-hydroxy-2-heptylquinoline (HHQ), accumulated in the cells. Taken together, these results show the involvement of OprF in P. aeruginosa virulence, at least partly through modulation of the quorum-sensing network. This is the first study showing a link between OprF, PQS synthesis, T3SS, and virulence factor production, providing novel insights into virulence expression.
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Affiliation(s)
- Laurène Fito-Boncompte
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Annelise Chapalain
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Emeline Bouffartigues
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Hichem Chaker
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Olivier Lesouhaitier
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Gwendoline Gicquel
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Alexis Bazire
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Amar Madi
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Nathalie Connil
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Wilfried Véron
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Laure Taupin
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Bertrand Toussaint
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Pierre Cornelis
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Qing Wei
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Koki Shioya
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Eric Déziel
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Marc G. J. Feuilloley
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Nicole Orange
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Alain Dufour
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
| | - Sylvie Chevalier
- Laboratoire de Microbiologie du Froid, Signaux et Micro-Environnement, EA 4312, Normandie Sécurité Sanitaire, Université de Rouen, Rouen, France, Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, Lorient, France, Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology (VIB), Vrije Universiteit Brussel, Brussels, Belgium, INRS-Institut Armand-Frappier, Laval, Québec, Canada, TIMC-IMAG, TheREx, Thérapeutiques Recombinantes Expérimentales, UMR5525 CNRS-Université Joseph Fourier, Grenoble, France
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Factors affecting the folding of Pseudomonas aeruginosa OprF porin into the one-domain open conformer. mBio 2010; 1. [PMID: 20978537 PMCID: PMC2957080 DOI: 10.1128/mbio.00228-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 09/17/2010] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas aeruginosa OprF is a largely monomeric outer membrane protein that allows the slow, nonspecific transmembrane diffusion of solutes. This protein folds into two different conformers, with the majority conformer folding into a two-domain conformation that has no porin activity and the minority conformer into a one-domain conformation with high porin activity and presumably consisting of a large β barrel. We examined the factors that control the divergent folding pathways of OprF. OprF contains four Cys residues in the linker region connecting the N-terminal β-barrel domain and the C-terminal globular domain in the majority conformer. Prevention of disulfide bond formation either by expression of OprF in an Escherichia coli dsbA strain grown with dithiothreitol or by replacement of all Cys residues with serine (CS OprF) increased the specific pore-forming activity of OprF significantly. Replacement of Phe160 with Ile at the end of the β-barrel termination signal as well as replacement of Lys164 in the linker region with Gly, Cys, or Glu increased porin activity 2-fold. Improving a potential β-barrel termination signal in the periplasmic domain by replacement of Asp211 with asparagine also increased porin activity. The porin activity could be improved about 5-fold by the combination of these replacements. OprF mutants with higher porin activity were shown to contain more one-domain conformers by surface labeling of the A312C residue in intact cells, as this residue is located in the periplasmic domain in the two-domain conformers. Finally, when the OprF protein was expressed in an E. coli strain lacking the periplasmic chaperone Skp, the CS OprF protein exhibited increased pore-forming activity. High intrinsic levels of resistance to many antimicrobial agents, seen in Gram-negative bacterial species such as Pseudomonas aeruginosa and Acinetobacter species, are largely due to the extremely low permeability of their major porin OprF and OmpA. Because this low permeability is caused by the fact that these proteins mostly fold into a two-domain conformer without pores, knowledge as to what conditions increase the production of the pore-forming minority conformer may lead to dramatic improvements in the treatment of infections by these bacteria. We have found several factors that increase the proportion of the pore-forming conformer up to 5-fold. Although these studies were done with Escherichia coli, they may serve as the starting point for the design of strategies for improvement of antimicrobial therapy for these difficult-to-treat pathogens, some strains of which have now attained the “pan-resistant” status.
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Effects of carbon and nitrogen sources on the proteome of Pseudomonas aeruginosa PA1 during rhamnolipid production. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.05.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Remans K, Vercammen K, Bodilis J, Cornelis P. Genome-wide analysis and literature-based survey of lipoproteins in Pseudomonas aeruginosa. MICROBIOLOGY-SGM 2010; 156:2597-2607. [PMID: 20616104 DOI: 10.1099/mic.0.040659-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen able to cause acute or chronic infections. Like all other Pseudomonas species, P. aeruginosa has a large genome, >6 Mb, encoding more than 5000 proteins. Many proteins are localized in membranes, among them lipoproteins, which can be found tethered to the inner or the outer membrane. Lipoproteins are translocated from the cytoplasm and their N-terminal signal peptide is cleaved by the signal peptidase II, which recognizes a specific sequence called the lipobox just before the first cysteine of the mature lipoprotein. A majority of lipoproteins are transported to the outer membrane via the LolCDEAB system, while those having an avoidance signal remain in the inner membrane. In Escherichia coli, the presence of an aspartate residue after the cysteine is sufficient to cause the lipoprotein to remain in the inner membrane, while in P. aeruginosa the situation is more complex and involves amino acids at position +3 and +4 after the cysteine. Previous studies indicated that there are 185 lipoproteins in P. aeruginosa, with a minority in the inner membrane. A reanalysis led to a reduction of this number to 175, while new retention signals could be predicted, increasing the percentage of inner-membrane lipoproteins to 20 %. About one-third (62 out of 175) of the lipoprotein genes are present in the 17 Pseudomonas genomes sequenced, meaning that these genes are part of the core genome of the genus. Lipoproteins can be classified into families, including those outer-membrane proteins having a structural role or involved in efflux of antibiotics. Comparison of various microarray data indicates that exposure to epithelial cells or some antibiotics, or conversion to mucoidy, has a major influence on the expression of lipoprotein genes in P. aeruginosa.
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Affiliation(s)
- Kim Remans
- Department of Molecular and Cellular Interactions, Structural Biology Brussels, VIB, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Ken Vercammen
- Department of Molecular and Cellular Interactions, Microbial Interactions, VIB, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Josselin Bodilis
- Groupe Microbiologie, Laboratoire M2C, UMR CNRS 6143, UFR des Sciences - Université de Rouen, 76821 Mont Saint Aignan, France
| | - Pierre Cornelis
- Department of Molecular and Cellular Interactions, Microbial Interactions, VIB, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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35
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Chen YY, Wu CH, Lin JW, Weng SF, Tseng YH. Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity. MICROBIOLOGY-SGM 2010; 156:2842-2854. [PMID: 20522496 DOI: 10.1099/mic.0.039420-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Xanthomonas campestris pv. campestris (Xcc) is the phytopathogen that causes black rot in crucifers. The xanthan polysaccharide and extracellular enzymes produced by this organism are virulence factors, the expression of which is upregulated by Clp (CRP-like protein) and DSF (diffusible signal factor), which is synthesized by RpfF. It is also known that biofilm formation/dispersal, regulated by the effect of controlled synthesis of DSF on cell-cell signalling, is required for virulence. Furthermore, a deficiency in DSF causes cell aggregation with concomitant production of a gum-like substance that can be dispersed by addition of DSF or digested by exogenous endo-beta-1,4-mannanase expressed by Xcc. In this study, Western blotting of proteins from a mopB mutant (XcMopB) showed Xcc MopB to be the major outer-membrane protein (OMP); Xcc MopB shared over 97 % identity with homologues from other members of Xanthomonas. Similarly to the rpfF mutant, XcMopB formed aggregates with simultaneous production of a gummy substance, but these aggregates could not be dispersed by DSF or endo-beta-1,4-mannanase, indicating that different mechanisms were involved in aggregation. In addition, XcMopB showed surface deformation, altered OMP composition, impaired xanthan production, increased sensitivity to stressful conditions including SDS, elevated temperature and changes in pH, reduced adhesion and motility and defects in pathogenesis. The finding that the major OMP is required for pathogenicity is unprecedented in phytopathogenic bacteria.
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Affiliation(s)
- Yih-Yuan Chen
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Chieh-Hao Wu
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Juey-Wen Lin
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Shu-Fen Weng
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Yi-Hsiung Tseng
- Institute of Microbiology, Immunology and Molecular Medicine, Tzu Chi University, Hualien 907, Taiwan, ROC
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36
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Roma-Rodrigues C, Santos PM, Benndorf D, Rapp E, Sá-Correia I. Response of Pseudomonas putida KT2440 to phenol at the level of membrane proteome. J Proteomics 2010; 73:1461-78. [DOI: 10.1016/j.jprot.2010.02.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/04/2010] [Accepted: 02/05/2010] [Indexed: 12/11/2022]
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Wexler HM, Tenorio E, Pumbwe L. Characteristics of Bacteroides fragilis lacking the major outer membrane protein, OmpA. MICROBIOLOGY-SGM 2009; 155:2694-2706. [PMID: 19497947 DOI: 10.1099/mic.0.025858-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OmpA1 is the major outer membrane protein of the Gram-negative anaerobic pathogen Bacteroides fragilis. We identified three additional conserved ompA homologues (ompA2-ompA4) and three less homologous ompA-like genes (ompAs 5, 6 and 7) in B. fragilis. We constructed an ompA1 disruption mutant in B. fragilis 638R (WAL6 OmegaompA1) using insertion-mediated mutagenesis. WAL6 OmegaompA1 formed much smaller colonies and had smaller, rounder forms on Gram stain analysis than the parental strain or other unrelated disruption mutants. SDS-PAGE and Western blot analysis (with anti-OmpA1 IgY) of the OMP patterns of WAL6 OmegaompA1 grown in both high- and low-salt media did not reveal any other OmpA proteins even under osmotic stress. An ompA1 deletant (WAL186DeltaompA1) was constructed using a two-step double-crossover technique, and an ompA 'reinsertant', WAL360+ompA1, was constructed by reinserting the ompA gene into WAL186DeltaompA1. WAL186DeltaompA1 was significantly more sensitive to exposure to SDS, high salt and oxygen than the parental (WAL108) or reinsertant (WAL360+ompA1) strain. No significant change was seen in MICs of a variety of antimicrobials for either WAL6 OmegaompA1 or WAL186DeltaompA1 compared to WAL108. RT-PCR revealed that all of the ompA genes are transcribed in the parental strain and in the disruption mutant, but, as expected, ompA1 is not transcribed in WAL186DeltaompA1. Unexpectedly, ompA4 is also not transcribed in WAL186DeltaompA1. A predicted structure indicated that among the four OmpA homologues, the barrel portion is more conserved than the loops, except for specific conserved patches on loop 1 and loop 3. The presence of multiple copies of such similar genes in one organism would suggest a critical role for this protein in B. fragilis.
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Affiliation(s)
- Hannah M Wexler
- Department of Medicine, UCLA School of Medicine, 405 Hilgard Ave, Los Angeles, CA 90095, USA
- Greater Los Angeles Veterans Administration Healthcare System, University of California, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA
| | - Elizabeth Tenorio
- Department of Medicine, UCLA School of Medicine, 405 Hilgard Ave, Los Angeles, CA 90095, USA
- Greater Los Angeles Veterans Administration Healthcare System, University of California, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA
| | - Lilian Pumbwe
- Greater Los Angeles Veterans Administration Healthcare System, University of California, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA
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38
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Travensolo RF, Carareto-Alves LM, Costa MVCG, Lopes TJS, Carrilho E, Lemos EGM. Xylella fastidiosa gene expression analysis by DNA microarrays. Genet Mol Biol 2009; 32:340-53. [PMID: 21637690 PMCID: PMC3036931 DOI: 10.1590/s1415-47572009005000038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 11/24/2008] [Indexed: 11/30/2022] Open
Abstract
Xylella fastidiosa genome sequencing has generated valuable data by identifying genes acting either on metabolic pathways or in associated pathogenicity and virulence. Based on available information on these genes, new strategies for studying their expression patterns, such as microarray technology, were employed. A total of 2,600 primer pairs were synthesized and then used to generate fragments using the PCR technique. The arrays were hybridized against cDNAs labeled during reverse transcription reactions and which were obtained from bacteria grown under two different conditions (liquid XDM(2) and liquid BCYE). All data were statistically analyzed to verify which genes were differentially expressed. In addition to exploring conditions for X. fastidiosa genome-wide transcriptome analysis, the present work observed the differential expression of several classes of genes (energy, protein, amino acid and nucleotide metabolism, transport, degradation of substances, toxins and hypothetical proteins, among others). The understanding of expressed genes in these two different media will be useful in comprehending the metabolic characteristics of X. fastidiosa, and in evaluating how important certain genes are for the functioning and survival of these bacteria in plants.
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Affiliation(s)
- Regiane F Travensolo
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, Universidade Estadual Paulista Júlio de Mesquita Filho, Jaboticabal, SP Brazil
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39
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Genomewide identification of genetic determinants of antimicrobial drug resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2009; 53:2522-31. [PMID: 19332674 DOI: 10.1128/aac.00035-09] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of antimicrobial drug resistance is of enormous public concern due to the increased risk of delayed treatment of infections, the increased length of hospital stays, the substantial increase in the cost of care, and the high risk of fatal outcomes. A prerequisite for the development of effective therapy alternatives is a detailed understanding of the diversity of bacterial mechanisms that underlie drug resistance, especially for problematic gram-negative bacteria such as Pseudomonas aeruginosa. This pathogen has impressive chromosomally encoded mechanisms of intrinsic resistance, as well as the potential to mutate, gaining resistance to current antibiotics. In this study we have screened the comprehensive nonredundant Harvard PA14 library for P. aeruginosa mutants that exhibited either increased or decreased resistance against 19 antibiotics commonly used in the clinic. This approach identified several genes whose inactivation sensitized the bacteria to a broad spectrum of different antimicrobials and uncovered novel genetic determinants of resistance to various classes of antibiotics. Knowledge of the enhancement of bacterial susceptibility to existing antibiotics and of novel resistance markers or modifiers of resistance expression may lay the foundation for effective therapy alternatives and will be the basis for the development of new strategies in the control of problematic multiresistant gram-negative bacteria.
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40
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Straatsma TP, Soares TA. Characterization of the outer membrane protein OprF of Pseudomonas aeruginosa in a lipopolysaccharide membrane by computer simulation. Proteins 2009; 74:475-88. [PMID: 18655068 DOI: 10.1002/prot.22165] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The N-terminal domain of outer membrane protein OprF of Pseudomonas aeruginosa forms a membrane spanning eight-stranded antiparallel beta-barrel domain that folds into a membrane channel with low conductance. The structure of this protein has been modeled after the crystal structure of the homologous protein OmpA of Escherichia coli. A number of molecular dynamics simulations have been carried out for the homology modeled structure of OprF in an explicit molecular model for the rough lipopolysaccharide (LPS) outer membrane of P. aeruginosa. The structural stability of the outer membrane model as a result of the strong electrostatic interactions compared with simple lipid bilayers is restricting both the conformational flexibility and the lateral diffusion of the porin in the membrane. Constricting side-chain interactions within the pore are similar to those found in reported simulations of the protein in a solvated lipid bilayer membrane. Because of the strong interactions between the loop regions of OprF and functional groups in the saccharide core of the LPS, the entrance to the channel from the extracellular space is widened compared with the lipid bilayer simulations in which the loops are extruding in the solvent. The specific electrostatic signature of the LPS membrane, which results in a net intrinsic dipole across the membrane, is found to be altered by the presence of OprF, resulting in a small electrically positive patch at the position of the channel.
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Affiliation(s)
- T P Straatsma
- Computational Sciences and Mathematics Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
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41
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Opr86 is essential for viability and is a potential candidate for a protective antigen against biofilm formation by Pseudomonas aeruginosa. J Bacteriol 2008; 190:3969-78. [PMID: 18390657 DOI: 10.1128/jb.02004-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that is one of the most refractory to therapy when it forms biofilms in the airways of cystic fibrosis patients. To date, studies regarding the production of an immunogenic and protective antigen to inhibit biofilm formation by P. aeruginosa have been superficial. The previously uncharacterized outer membrane protein (OMP) Opr86 (PA3648) of P. aeruginosa is a member of the Omp85 family, of which homologs have been found in all gram-negative bacteria. Here we verify the availability of Opr86 as a protective antigen to inhibit biofilm formation by P. aeruginosa PAO1 and several other isolates. A mutant was constructed in which Opr86 expression could be switched on or off through a tac promoter-controlled opr86 gene. The result, consistent with previous Omp85 studies, showed that Opr86 is essential for viability and plays a role in OMP assembly. Depletion of Opr86 resulted in streptococci-like morphological changes and liberation of excess membrane vesicles. A polyclonal antibody against Opr86 which showed reactivity to PAO1 cells was obtained. The antibody inhibited biofilm formation by PAO1 and the other clinical strains tested. Closer examination of early attachment revealed that cells treated with the antibody were unable to attach to the surface. Our data suggest that Opr86 is a critical OMP and a potential candidate as a protective antigen against biofilm formation by P. aeruginosa.
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42
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Guyard-Nicodème M, Bazire A, Hémery G, Meylheuc T, Mollé D, Orange N, Fito-Boncompte L, Feuilloley M, Haras D, Dufour A, Chevalier S. Outer membrane Modifications of Pseudomonas fluorescens MF37 in Response to Hyperosmolarity. J Proteome Res 2008; 7:1218-25. [DOI: 10.1021/pr070539x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Muriel Guyard-Nicodème
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Alexis Bazire
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Gaëlle Hémery
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Thierry Meylheuc
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Daniel Mollé
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Nicole Orange
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Laurène Fito-Boncompte
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Marc Feuilloley
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Dominique Haras
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Alain Dufour
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
| | - Sylvie Chevalier
- Laboratoire de Microbiologie du Froid, UPRES EA 2123,
Université de Rouen, Evreux, France, Laboratoire de Biotechnologie
et Chimie Marines, EA 3884, Université de Bretagne-Sud. Lorient,
France, Laboratoire Bioadhésion et Hygiène des Matériaux,
UMR/INRA-ENSIA, Massy, France, and INRA-Agrocampus, UMR 1253, Science
et Technologie du Lait et de l’Oeuf, Rennes, France
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43
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Bratu S, Landman D, Gupta J, Quale J. Role of AmpD, OprF and penicillin-binding proteins in beta-lactam resistance in clinical isolates of Pseudomonas aeruginosa. J Med Microbiol 2007; 56:809-814. [PMID: 17510267 DOI: 10.1099/jmm.0.47019-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this study, the mechanisms leading to increased chromosomal AmpC beta-lactamase expression and the contributory roles of the outer-membrane protein OprF and penicillin-binding proteins were analysed in 33 characterized clinical isolates of Pseudomonas aeruginosa. The genes ampD and ampE were analysed by PCR and DNA sequencing. Expression of the gene oprF was assessed using real-time RT-PCR, and penicillin-binding proteins were analysed using a chemiluminescence assay. Several of the isolates with increased ampC expression had major deletions affecting ampD, although in some isolates the mechanism of increased ampC expression could not be ascertained. Occasional isolates had increased expression of both ampC and oprF but remained susceptible to cephalosporins, suggesting that increased beta-lactamase activity could not offset increased outer-membrane permeability. There were no discernible changes in penicillin-binding proteins. Genomic deletions in ampD were observed in selected clinical isolates of P. aeruginosa with increased expression of the AmpC beta-lactamase. For some isolates, cephalosporin resistance was dependent upon the interplay of ampC and oprF expression.
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Affiliation(s)
- Simona Bratu
- Division of Infectious Diseases, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - David Landman
- Division of Infectious Diseases, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - Jyoti Gupta
- Division of Infectious Diseases, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | - John Quale
- Division of Infectious Diseases, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
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Pocanschi CL, Dahmane T, Gohon Y, Rappaport F, Apell HJ, Kleinschmidt JH, Popot JL. Amphipathic Polymers: Tools To Fold Integral Membrane Proteins to Their Active Form. Biochemistry 2006; 45:13954-61. [PMID: 17115690 DOI: 10.1021/bi0616706] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Among the major obstacles to pharmacological and structural studies of integral membrane proteins (MPs) are their natural scarcity and the difficulty in overproducing them in their native form. MPs can be overexpressed in the non-native state as inclusion bodies, but inducing them to achieve their functional three-dimensional structure has proven to be a major challenge. We describe here the use of an amphipathic polymer, amphipol A8-35, as a novel environment that allows both beta-barrel and alpha-helical MPs to fold to their native state, in the absence of detergents or lipids. Amphipols, which are extremely mild surfactants, appear to favor the formation of native intramolecular protein-protein interactions over intermolecular or protein-surfactant ones. The feasibility of the approach is demonstrated using as models OmpA and FomA, two outer membrane proteins from the eubacteria Escherichia coli and Fusobacterium nucleatum, respectively, and bacteriorhodopsin, a light-driven proton pump from the plasma membrane of the archaebacterium Halobacterium salinarium.
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Affiliation(s)
- Cosmin L Pocanschi
- Fachbereich Biologie, Fach M 694, Universität Konstanz, D-78457 Konstanz, Germany
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Bodilis J, Hedde M, Orange N, Barray S. OprF polymorphism as a marker of ecological niche in Pseudomonas. Environ Microbiol 2006; 8:1544-51. [PMID: 16913915 DOI: 10.1111/j.1462-2920.2006.01045.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OprF is the major outer-membrane protein of Pseudomonas sensu stricto (rRNA group I). In addition to playing a role as porin, membrane structural protein and root adhesion, this pleiotropic protein shows a length polymorphism corresponding to two types of OprF, termed OprF type 1 and OprF type 2. In a previous work, all the P. fluorescens isolated from bulk soil (non-rhizospheric) were shown to possess oprF type 1, while all the clinical P. fluorescens isolates and most rhizospheric strains corresponded to type 2. In this study, we further investigated the relation between the OprF polymorphism and the ecological niche by developing a culture-independent approach (a ratio polymerase chain reaction) to measure the percentage of each oprF type in environmental DNA samples, including two different soils and three different cultured plants (flax, wheat and grassland). Although the proportions of oprF type 2 between rhizospheric samples were quite variable, they were always very significantly higher (P<0.001) than the proportions of oprF type 2 of the adjacent bulk soil where the vast majority of oprF (>95%) corresponded to type 1. We discuss the potential applications of this ecological fingerprint in an agronomic and taxonomic point of view.
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Affiliation(s)
- Josselin Bodilis
- LMDF (Laboratoire de Microbiologie Du Froid), UPRES 2123, Université de Rouen, 76821 Mont Saint Aignan, France.
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Bodilis J, Barray S. Molecular evolution of the major outer-membrane protein gene (oprF) of Pseudomonas. MICROBIOLOGY-SGM 2006; 152:1075-1088. [PMID: 16549671 DOI: 10.1099/mic.0.28656-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The major outer-membrane protein of Pseudomonas, OprF, is multifunctional. It is a non-specific porin that plays a role in maintenance of cell shape, in growth in a low-osmolarity environment, and in adhesion to various supports or molecules. OprF has been studied extensively for its utility as a vaccine component, its role in antimicrobial drug resistance, and its porin function. The authors have previously shown important differences between the OprF and 16S rDNA phylogenies: Pseudomonas fluorescens isolates split into two quite separate clusters, probably according to their ecological niche. In this study, the evolutionary history of the oprF gene was investigated further. The study of G+C content at the third codon position, synonymous codon usage (codon adaptation index, CAI) and genomic context showed no evidence of horizontal transfer or gene duplication. Similarly, a robust likelihood test of incongruence showed no significant incongruence between the oprF phylogeny and the species phylogeny. In addition, the ratio of nonsynonymous mutations to synonymous mutations (K(a)/K(s)) is high between the different clusters, especially between the two clusters containing P. fluorescens isolates, highlighting important modifications in evolutionary constraints during the history of the oprF gene. Since OprF is known as a pleiotropic protein, modifications in evolutionary constraints could have resulted from variations in cryptic functions, correlated with the ecological fingerprint. Finally, relaxed constraints and/or episodic positive evolution, especially for some P. fluorescens strains, could have led to a phylogeny reconstruction artifact.
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Affiliation(s)
- Josselin Bodilis
- LMDF (Laboratoire de Microbiologie Du Froid), UPRES 2123, ABISS (Atelier de Biologie, Informatique, Statistique et Sociolinguistinque), Université de Rouen, 76821 Mont Saint Aignan, France
| | - Sylvie Barray
- LMDF (Laboratoire de Microbiologie Du Froid), UPRES 2123, ABISS (Atelier de Biologie, Informatique, Statistique et Sociolinguistinque), Université de Rouen, 76821 Mont Saint Aignan, France
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Sugawara E, Nestorovich EM, Bezrukov SM, Nikaido H. Pseudomonas aeruginosa porin OprF exists in two different conformations. J Biol Chem 2006; 281:16220-9. [PMID: 16595653 PMCID: PMC2846725 DOI: 10.1074/jbc.m600680200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The major nonspecific porin of Pseudomonas aeruginosa, OprF, produces a large channel yet allows only a slow diffusion of various solutes. Here we provide an explanation of this apparent paradox. We first show, by introduction of tobacco etch virus protease cleavage site in the middle of OprF protein, that most of OprF population folds as a two-domain protein with an N-terminal beta-barrel domain and a C-terminal periplasmic domain rich in alpha-helices. However, sedimentation of unilamellar proteoliposomes through an iso-osmotic gradient showed that only about 5% of the OprF population produced open channels. Gel filtration showed that the open channel conformers tended to occur in oligomeric associations. Because the open channel conformer is likely to fold as a single domain protein with a large beta-barrel, we reasoned that residues near the C terminus may be exposed on cell surface in this conformer. Introduction of a cysteine residue at position 312 produced a functional mutant protein. By using bulky biotinylation reagents on intact cells, we showed that this cysteine residue was not exposed on cell surface in most of the OprF population. However, the minority OprF population that was biotinylated in such experiments was enriched for the conformer with pore-forming activity and had a 10-fold higher pore-forming specific activity than the bulk OprF population. Finally trypsin treatment, which preferentially cleaves the C-terminal domain of the two-domain conformer, did not affect the pore-forming activity of OprF nor did it digest the minority conformer whose residue 312 is exposed on cell surface.
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Affiliation(s)
- Etsuko Sugawara
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202
| | - Ekaterina M. Nestorovich
- Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bethesda, Maryland 20892-0924
| | - Sergey M. Bezrukov
- Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bethesda, Maryland 20892-0924
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202
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Nestorovich EM, Sugawara E, Nikaido H, Bezrukov SM. Pseudomonas aeruginosa porin OprF: properties of the channel. J Biol Chem 2006; 281:16230-7. [PMID: 16617058 PMCID: PMC2846715 DOI: 10.1074/jbc.m600650200] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Using ion channel reconstitution in planar lipid bilayers, we examined the channel-forming activity of subfractions of Pseudomonas aeruginosa OprF, which was shown to exist in two different conformations: a minority single domain conformer and a majority two-domain conformer (Sugawara, E., Nestorovich, E. M., Bezrukov, S. M., and Nikaido, H. (2006) J. Biol. Chem. 281, 16220-16229). With the fraction depleted for the single domain conformer, we were unable to detect formation of any channels with well defined conductance levels. With the unfractionated OprF, we saw only rare channel formation. However, with the single domain-enriched fraction of OprF, we observed regular insertion of channels with highly reproducible conductances. Single OprF channels demonstrate rich kinetic behavior exhibiting spontaneous transitions between several subconformations that differ in ionic conductance and radius measured in polymer exclusion experiments. Although we showed that the effective radius of the most conductive conformation exceeds that of the general outer membrane porin of Escherichia coli, OmpF, we also found that a single OprF channel mainly exists in weakly conductive subconformations and switches to the fully open state for a short time only. Therefore, the low permeability of OprF reported earlier may be due to two factors: mainly to the paucity of the single domain conformer in the OprF population and secondly to the predominance of weakly conductive subconformations within the single domain conformer.
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Affiliation(s)
- Ekaterina M. Nestorovich
- Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bethesda, Maryland 20892-0924
| | - Etsuko Sugawara
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202
| | - Sergey M. Bezrukov
- Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bethesda, Maryland 20892-0924
- To whom correspondence should be addressed: Laboratory of Physical and Structural Biology, NICHD, National Institutes of Health, Bldg. 9 Rm. 1N124, 9 Memorial Dr., Bethesda, MD 20892-0924. Tel.: 301-402-4701; Fax: 301-496-2172;
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Coquet L, Cosette P, Dé E, Galas L, Vaudry H, Rihouey C, Lerouge P, Junter GA, Jouenne T. Immobilization induces alterations in the outer membrane protein pattern of Yersinia ruckeri. J Proteome Res 2006; 4:1988-98. [PMID: 16335943 DOI: 10.1021/pr050165c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We compared the outer membrane protein (OMP) pattern of 2-day-old immobilized Yersinia ruckericells (IC) with that of early (FC24) and late (FC48) stationary-phase planktonic counterparts. Fifty-five OMPs were identified. Principal component analysis discriminated between the protein maps of FC and IC. Some OMPs involved in bacterial adaptation were accumulated by both FC48 and IC but the expression of other proteins was controlled by the sessile mode of growth.
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Affiliation(s)
- Laurent Coquet
- IBBR Group, Laboratory Polymères, Biopolymères, Membranes, UMR 6522 CNRS, University of Rouen, France
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50
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Nandi B, Nandy RK, Sarkar A, Ghose AC. Structural features, properties and regulation of the outer-membrane protein W (OmpW) of Vibrio cholerae. Microbiology (Reading) 2005; 151:2975-2986. [PMID: 16151208 DOI: 10.1099/mic.0.27995-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The outer-membrane protein OmpW ofVibrio choleraewas studied with respect to its structure, functional properties and regulation of expression. On SDS-PAGE, the membrane-associated form of OmpW protein (solubilized by either 0·1 % or 2 % SDS at 25 °C) migrated as a monomer of 19 kDa that changed to 21 kDa on boiling. The protein was hyperexpressed inEscherichia coliin the histidine-tagged form and the purified His6-OmpW (heated or unheated) migrated as a 23 kDa protein on SDS-PAGE. Circular dichroism and Fourier-transform infrared spectroscopic analyses of the recombinant protein showed the presence ofβ-structures (∼40 %) with minor amounts (8–15 %) ofα-helix. These results were consistent with those obtained by computational analysis of the sequence data of the protein using the secondary structure prediction program Jnet. The recombinant protein did not exhibit any porin-like property in a liposome-swelling assay. An antiserum to the purified protein induced a moderate level (66·6 % and 33·3 % at 1 : 50 and 1 : 100 dilutions, respectively) of passive protection against live vibrio challenge in a suckling mouse model. OmpW-deficient mutants ofV. choleraestrains were generated by insertion mutagenesis. In a competitive assay in mice, the intestinal colonization activities of these mutants were found to be either only marginally diminished (for O1 strains) or 10-fold less (for an O139 strain) as compared to those of the corresponding wild-type strains. The OmpW protein was expressedin vivoas well asin vitroin liquid culture medium devoid of glucose. Interestingly, the glucose-dependent regulation of OmpW expression was less prominent in a ToxR−mutant ofV. cholerae. Further, the expression of OmpW protein was found to be dependent onin vitrocultural conditions such as temperature, salinity, and availability of nutrients or oxygen. These results suggest that the modulation of OmpW expression by environmental factors may be linked to the adaptive response of the organism under stress conditions.
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Affiliation(s)
- Bisweswar Nandi
- Department of Microbiology, Bose Institute, Kolkata-700 054, India
| | - Ranjan K Nandy
- National Institute of Cholera and Enteric Diseases, P33 CIT Road, Scheme XM, Kolkata-700 010, India
| | - Amit Sarkar
- Department of Microbiology, Bose Institute, Kolkata-700 054, India
| | - Asoke C Ghose
- National Institute of Cholera and Enteric Diseases, P33 CIT Road, Scheme XM, Kolkata-700 010, India
- Department of Microbiology, Bose Institute, Kolkata-700 054, India
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