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Lang M, Carvalho A, Baharoglu Z, Mazel D. Aminoglycoside uptake, stress, and potentiation in Gram-negative bacteria: new therapies with old molecules. Microbiol Mol Biol Rev 2023; 87:e0003622. [PMID: 38047635 PMCID: PMC10732077 DOI: 10.1128/mmbr.00036-22] [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] [Indexed: 12/05/2023] Open
Abstract
SUMMARYAminoglycosides (AGs) are long-known molecules successfully used against Gram-negative pathogens. While their use declined with the discovery of new antibiotics, they are now classified as critically important molecules because of their effectiveness against multidrug-resistant bacteria. While they can efficiently cross the Gram-negative envelope, the mechanism of AG entry is still incompletely understood, although this comprehension is essential for the development of new therapies in the face of the alarming increase in antibiotic resistance. Increasing antibiotic uptake in bacteria is one strategy to enhance effective treatments. This review aims, first, to consolidate old and recent knowledge about AG uptake; second, to explore the connection between AG-dependent bacterial stress and drug uptake; and finally, to present new strategies of potentiation of AG uptake for more efficient antibiotic therapies. In particular, we emphasize on the connection between sugar transport and AG potentiation.
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Affiliation(s)
- Manon Lang
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - André Carvalho
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Zeynep Baharoglu
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Didier Mazel
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
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2
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Cyriaque V, Madsen JS, Fievez L, Leroy B, Hansen LH, Bureau F, Sørensen SJ, Wattiez R. Lead Drives Complex Dynamics of a Conjugative Plasmid in a Bacterial Community. Front Microbiol 2021; 12:655903. [PMID: 34122370 PMCID: PMC8195591 DOI: 10.3389/fmicb.2021.655903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/06/2021] [Indexed: 01/01/2023] Open
Abstract
Plasmids carrying metal resistance genes (MRGs) have been suggested to be key ecological players in the adaptation of metal-impacted microbial communities, making them promising drivers of bio-remediation processes. However, the impact of metals on plasmid-mediated spread of MRGs through selection, plasmid loss, and transfer is far from being fully understood. In the present study, we used two-member bacterial communities to test the impact of lead on the dispersal of the IncP plasmid pKJK5 from a Pseudomonas putida KT2440 plasmid donor and two distinct recipients, Variovorax paradoxus B4 or Delftia acidovorans SPH-1 after 4 and 10 days of mating. Two versions of the plasmid were used, carrying or not carrying the lead resistance pbrTRABCD operon, to assess the importance of fitness benefit and conjugative potential for the dispersal of the plasmid. The spread dynamics of metal resistance conveyed by the conjugative plasmid were dependent on the recipient and the lead concentration: For V. paradoxus, the pbr operon did not facilitate neither lead resistance nor variation in plasmid spread. The growth gain brought by the pbr operon to D. acidovorans SPH-1 and P. putida KT2440 at 1 mM Pb enhanced the spread of the plasmid. At 1.5 mM Pb after 4 days, the proteomics results revealed an oxidative stress response and an increased abundance of pKJK5-encoded conjugation and partitioning proteins, which most likely increased the transfer of the control plasmid to D. acidovorans SPH-1 and ensured plasmid maintenance. As a consequence, we observed an increased spread of pKJK5-gfp. Conversely, the pbr operon reduced the oxidative stress response and impeded the rise of conjugation- and partitioning-associated proteins, which slowed down the spread of the pbr carrying plasmid. Ultimately, when a fitness gain was recorded in the recipient strain, the spread of MRG-carrying plasmids was facilitated through positive selection at an intermediate metal concentration, while a high lead concentration induced oxidative stress with positive impacts on proteins encoding plasmid conjugation and partitioning.
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Affiliation(s)
- Valentine Cyriaque
- Laboratory of Proteomics and Microbiology, Research Institute for Biosciences, University of Mons, Mons, Belgium.,Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Stenløkke Madsen
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Laurence Fievez
- Cellular and Molecular Immunology Service, GIGA Research, University of Liège (ULG), Liège, Belgium
| | - Baptiste Leroy
- Laboratory of Proteomics and Microbiology, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Lars H Hansen
- Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Fabrice Bureau
- Cellular and Molecular Immunology Service, GIGA Research, University of Liège (ULG), Liège, Belgium
| | - Søren J Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ruddy Wattiez
- Laboratory of Proteomics and Microbiology, Research Institute for Biosciences, University of Mons, Mons, Belgium
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3
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Sakuda A, Suzuki-Minakuchi C, Matsui K, Takahashi Y, Okada K, Yamane H, Shintani M, Nojiri H. Divalent cations increase the conjugation efficiency of the incompatibility P-7 group plasmid pCAR1 among different Pseudomonas hosts. MICROBIOLOGY-SGM 2017; 164:20-27. [PMID: 29185954 DOI: 10.1099/mic.0.000583] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The incompatibility (Inc) P-7 group plasmid pCAR1 can be efficiently transferred among bacteria in artificial microcosms in the presence of divalent cations Ca2+ and Mg2+. One-on-one mating assays between Pseudomonas strains with different plasmids showed that the promotion of conjugation efficiency by divalent cations was exhibited in other plasmids, including pB10 and NAH7; however, this effect was larger in IncP-7 plasmids. The impact on pCAR1 conjugation differed according to donor-recipient pairs, and conjugation efficiency promotion was clearly detected between the donors P. resinovorans CA10dm4 and P. fluorescens Pf0-1 and the recipients P. putida KT2440 and CA10dm4. Transcriptome analyses showed that pCAR1 gene expression did not respond to cation changes, including the tra/trh genes involved in its transfer. However, the transcription of oprH genes, encoding putative outer-membrane proteins in both the donor and the recipient, were commonly upregulated under cation-limited conditions. The conjugation frequency of pCAR1 in the KT2440 oprH mutant was found not to respond to cations. This effect was partially recovered by complementation with the oprH gene, suggesting that OprH is involved in the increase of pCAR1 conjugation efficiency by divalent cations.
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Affiliation(s)
- Ayako Sakuda
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
| | | | - Kazuhiro Matsui
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yurika Takahashi
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan.,Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Toyama 939-0398, Japan
| | - Kazunori Okada
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hisakazu Yamane
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan.,Present address: Department of Biosciences, Teikyo University, Tochigi 320-8551, Japan
| | - Masaki Shintani
- Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka 432-8561, Japan.,Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Shizuoka 432-8561, Japan
| | - Hideaki Nojiri
- Biotechnology Research Center, The University of Tokyo, Tokyo 113-8657, Japan
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4
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Li SS, Hu X, Zhao H, Li YX, Zhang L, Gong LJ, Guo J, Zhao HB. Quantitative analysis of cellular proteome alterations of Pseudomonas putida to naphthalene-induced stress. Biotechnol Lett 2015; 37:1645-54. [DOI: 10.1007/s10529-015-1828-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
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5
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Zavascki AP, Carvalhaes CG, Picão RC, Gales AC. Multidrug-resistantPseudomonas aeruginosaandAcinetobacter baumannii: resistance mechanisms and implications for therapy. Expert Rev Anti Infect Ther 2014; 8:71-93. [DOI: 10.1586/eri.09.108] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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6
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Friman H, Schechter A, Nitzan Y, Cahan R. Effect of external voltage on Pseudomonas putida F1 in a bio electrochemical cell using toluene as sole carbon and energy source. MICROBIOLOGY-SGM 2011; 158:414-423. [PMID: 22096152 DOI: 10.1099/mic.0.053298-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A bio electrochemical cell (BEC) was constructed as a typical two-chamber microbial fuel cell (MFC), except that it was operated under external voltage instead of constant resistance as in an MFC. The anode chamber contained a pure culture of Pseudomonas putida F1 grown in a minimal medium containing toluene as the sole carbon and energy source. Operating the BEC under external voltages of 75, 125, 175, 250 and 500 mV (versus an Ag/AgCl reference electrode) led to increased bacterial cell growth to an OD(600) of 0.62-0.75, while the control BEC, which was not connected to external voltage, reached an OD(600) of only 0.3. Examination of the current generated under external voltages of 75, 125, 175, 250 and 500 mV showed that the maximal currents were 11, 23, 28, 54 and 94 mA m(-2), respectively. Cyclic voltammetry experiments demonstrated an anodic peak at 270 mV, which may imply oxidation of a vital molecule. The average residual toluene concentration after 147 h in the BEC operated under external voltage was 22 %, whereas in the control BEC it was 81 %. Proteome analysis of bacterial cells grown in the BEC (125 mV) revealed two groups of proteins, which are ascribed to charge transfer in the bacterial cells and from the cell to the electrode. In conclusion, operating the BEC at 75-500 mV enabled growth of a pure culture of P. putida F1 and toluene degradation even in an oxygen-limited environment.
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Affiliation(s)
- Hen Friman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.,Department of Chemical Engineering and Biotechnology, Ariel University Center, Ariel 44837, Israel
| | - Alex Schechter
- Department of Biological Chemistry, Ariel University Center, Ariel 44837, Israel
| | - Yeshayahu Nitzan
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Rivka Cahan
- Department of Chemical Engineering and Biotechnology, Ariel University Center, Ariel 44837, Israel
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7
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Edrington TC, Kintz E, Goldberg JB, Tamm LK. Structural basis for the interaction of lipopolysaccharide with outer membrane protein H (OprH) from Pseudomonas aeruginosa. J Biol Chem 2011; 286:39211-23. [PMID: 21865172 DOI: 10.1074/jbc.m111.280933] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pseudomonas aeruginosa is a major nosocomial pathogen that infects cystic fibrosis and immunocompromised patients. The impermeability of the P. aeruginosa outer membrane contributes substantially to the notorious antibiotic resistance of this human pathogen. This impermeability is partially imparted by the outer membrane protein H (OprH). Here we have solved the structure of OprH in a lipid environment by solution NMR. The structure reveals an eight-stranded β-barrel protein with four extracellular loops of unequal size. Fast time-scale dynamics measurements show that the extracellular loops are disordered and unstructured. It was previously suggested that the function of OprH is to provide increased stability to the outer membranes of P. aeruginosa by directly interacting with lipopolysaccharide (LPS) molecules. Using in vivo and in vitro biochemical assays, we show that OprH indeed interacts with LPS in P. aeruginosa outer membranes. Based upon NMR chemical shift perturbations observed upon the addition of LPS to OprH in lipid micelles, we conclude that the interaction is predominantly electrostatic and localized to charged regions near both rims of the barrel, but also through two conspicuous tyrosines in the middle of the bilayer. These results provide the first molecular structure of OprH and offer evidence for multiple interactions between OprH and LPS that likely contribute to the antibiotic resistance of P. aeruginosa.
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Affiliation(s)
- Thomas C Edrington
- Center for Membrane Biology, University of Virginia, Charlottesville, Virginia 22908, USA
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8
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Papasotiriou DG, Markoutsa S, Meyer B, Papadioti A, Karas M, Tsiotis G. Comparison of the membrane subproteomes during growth of a new pseudomonas strain on lysogeny broth medium, glucose, and phenol. J Proteome Res 2008; 7:4278-88. [PMID: 18707154 DOI: 10.1021/pr800192n] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Study of the bacterial membrane proteome is a field of growing interest in the research of nutrient transport and processing. Pseudomonas sp. strain phDV1, a Gram-negative bacterium selected for its ability to degrade aromatic compounds, was monitored under different growth substrate conditions, using lysogeny broth medium (LB), glucose, and phenol as sole carbon source. The aim of this study was to characterize the membrane subproteomes of the Pseudomonas strain by proteomic means to assess the protein composition of this subcellular compartments, which appears fundamental for the biodegradation of aromatic compounds. A total number of 129 different proteins have been identified by MALDI-TOF/TOF, 19 of which are membrane proteins that belong to the inner membrane and 10 that belong to the outer membrane. Two membrane proteins were only expressed in the presence of the aromatic substrate. We identified a membrane protein involved in aromatic hydrocarbon degradation as well as a probable porin which may, in fact, function as an aromatic compound-specific porin. Although the presence of different transporters have been reported for different aromatic compounds such as toluene and benzoic acid, to our knowledge, these are the first phenol-inducible membrane transporters identified.
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Affiliation(s)
- Dimitrios G Papasotiriou
- Division of Biochemistry, Department of Chemistry, University of Crete, P.O. Box 2208, GR-71003 Voutes Heraklion, Greece
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9
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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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10
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Guina T, Wu M, Miller SI, Purvine SO, Yi EC, Eng J, Goodlett DR, Aebersold R, Ernst RK, Lee KA. Proteomic analysis of Pseudomonas aeruginosa grown under magnesium limitation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2003; 14:742-751. [PMID: 12837596 DOI: 10.1016/s1044-0305(03)00133-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study, large-scale qualitative and quantitative proteomic technology was applied to the analysis of the opportunistic bacterial pathogen Pseudomonas aeruginosa grown under magnesium limitation, an environmental condition previously shown to induce expression of various virulence factors. For quantitative analysis, whole cell and membrane proteins were differentially labeled with isotope-coded affinity tag (ICAT) reagents and ICAT reagent-labeled peptides were separated by two-dimensional chromatography prior to analysis by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) in an ion trap mass spectrometer (ITMS). To increase the number of protein identifications, gas-phase fractionation (GPF) in the m/z dimension was employed for analysis of ICAT peptides derived from whole cell extracts. The experiments confirmed expression of 1331 P. aeruginosa proteins of which 145 were differentially expressed upon limitation of magnesium. A number of conserved Gram-negative magnesium stress-response proteins involved in bacterial virulence were among the most abundant proteins induced in low magnesium. Comparative ICAT analysis of membrane versus whole cell protein indicated that growth of P. aeruginosa in low magnesium resulted in altered subcellular compartmentalization of large enzyme complexes such as ribosomes. This result was confirmed by 2-D PAGE analysis of P. aeruginosa outer membrane proteins. This study shows that large-scale quantitative proteomic technology can be successfully applied to the analysis of whole bacteria and to the discovery of functionally relevant biologic phenotypes.
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Affiliation(s)
- Tina Guina
- Department of Pediatrics, Division of Infectious Diseases, University of Washington, Seattle, Washington 98195, USA.
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11
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Guina T, Purvine SO, Yi EC, Eng J, Goodlett DR, Aebersold R, Miller SI. Quantitative proteomic analysis indicates increased synthesis of a quinolone by Pseudomonas aeruginosa isolates from cystic fibrosis airways. Proc Natl Acad Sci U S A 2003; 100:2771-6. [PMID: 12601166 PMCID: PMC151416 DOI: 10.1073/pnas.0435846100] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The opportunistic bacterial pathogen Pseudomonas aeruginosa colonizes airways of individuals with cystic fibrosis (CF) with resultant chronic destructive lung disease. P. aeruginosa adaptation to the CF airway includes biofilm formation and antibiotic resistance. Isolates from asymptomatic individuals in the first 3 years of life have unique characteristics, suggesting that adaptation occurs before clinical symptoms. One defined early adaptation is expression of a specific proinflammatory lipopolysaccharide (LPS) that is associated with antimicrobial peptide resistance. This CF-specific LPS is induced when P. aeruginosa is grown in medium that is limited for magnesium. Therefore, qualitative and quantitative proteomic approaches were used to define 1,331 P. aeruginosa proteins, of which 145 were differentially expressed on limitation of magnesium. Among proteins induced by low magnesium were enzymes essential for production of 2-heptyl 3-hydroxy 4-quinolone, the Pseudomonas quinolone signal (PQS), which interacts with the homoserine lactone signaling pathway. Measurement of PQS in P. aeruginosa isolates from asymptomatic children with CF indicated that strains with increased synthesis of PQS are present during early colonization of CF patient airways.
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Affiliation(s)
- Tina Guina
- Department of Pediatrics, Division of Infectious Diseases, University of Washington, Seattle, WA 98195, USA
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12
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Ernst RK, Yi EC, Guo L, Lim KB, Burns JL, Hackett M, Miller SI. Specific lipopolysaccharide found in cystic fibrosis airway Pseudomonas aeruginosa. Science 1999; 286:1561-5. [PMID: 10567263 DOI: 10.1126/science.286.5444.1561] [Citation(s) in RCA: 371] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cystic fibrosis (CF) patients develop chronic airway infections with Pseudomonas aeruginosa (PA). Pseudomonas aeruginosa synthesized lipopolysaccharide (LPS) with a variety of penta- and hexa-acylated lipid A structures under different environmental conditions. CF patient PA synthesized LPS with specific lipid A structures indicating unique recognition of the CF airway environment. CF-specific lipid A forms containing palmitate and aminoarabinose were associated with resistance to cationic antimicrobial peptides and increased inflammatory responses, indicating that they are likely to be involved in airway disease.
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Affiliation(s)
- R K Ernst
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
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13
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Macfarlane EL, Kwasnicka A, Ochs MM, Hancock RE. PhoP-PhoQ homologues in Pseudomonas aeruginosa regulate expression of the outer-membrane protein OprH and polymyxin B resistance. Mol Microbiol 1999; 34:305-16. [PMID: 10564474 DOI: 10.1046/j.1365-2958.1999.01600.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Rapid adaptation to environmental challenge is essential for the survival of many bacterial species, and is often effectively mediated by two-component regulatory systems. Part of the adaptive response of Pseudomonas aeruginosa to Mg2+ starvation is overexpression of the outer-membrane protein OprH and increased resistance to the polycationic antibiotic polymyxin B. Two overlapping open reading frames that encoded proteins with high similarities to the PhoP-PhoQ two-component regulatory system of Salmonella typhimurium were identified downstream of the oprH gene. A P. aeruginosa PhoP-null mutant, H851, was constructed by means of a phoP:xylE-GmR transcriptional fusion, and shown to be deficient in OprH expression. In contrast, an analogous PhoQ-null mutant, H854 (phoQ:xylE-GmR), exhibited constitutive overexpression of OprH. Normal Mg2+-regulated OprH expression could be restored in both mutants by complementation with a plasmid carrying the phoP and phoQ genes. Measurement of the catechol-2,3-dioxygenase activity, expressed from the xylE transcriptional fusion in strains H851 and H854, indicated that PhoP-PhoQ is involved in the regulation of phoP-phoQ as well as oprH. Reverse transcription polymerase chain reaction experiments and Northern blot analysis revealed linkage of oprH, phoP and phoQ into an operon that was demonstrated to be under the joint control of PhoP-PhoQ and Mg2+ ion concentration. In addition, studies of the polymyxin B resistance of the two mutant strains, H851 and H854, indicated that PhoP-PhoQ is involved in regulating P. aeruginosa polymyxin resistance in response to external Mg2+ concentrations.
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Affiliation(s)
- E L Macfarlane
- Department of Microbiology, 300, 6174 University Boulevard, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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14
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Ochsner UA, Vasil AI, Johnson Z, Vasil ML. Pseudomonas aeruginosa fur overlaps with a gene encoding a novel outer membrane lipoprotein, OmlA. J Bacteriol 1999; 181:1099-109. [PMID: 9973334 PMCID: PMC93485 DOI: 10.1128/jb.181.4.1099-1109.1999] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/1998] [Accepted: 12/09/1998] [Indexed: 11/20/2022] Open
Abstract
A novel outer membrane lipoprotein in Pseudomonas aeruginosa is encoded by the omlA gene, which was identified immediately upstream of the fur (ferric uptake regulator) gene. The omlA and fur genes were divergently transcribed and had overlapping promoter regions. The proximal fur P2 promoter and the omlA promoter shared a 5-bp DNA motif for their -10 promoter elements. The distal fur P1 promoter was located within the omlA coding sequence, and the omlA and fur T1 mRNAs overlapped by 154 nucleotides. Optimal expression of both fur and omlA required roughly 200 bp of DNA upstream of the promoter regions, suggesting the presence of cis-acting transcriptional activation elements located within the omlA and fur genes, respectively. The levels of Fur and OmlA proteins had no influence on omlA or fur expression, excluding any trans-acting cross-regulation between fur and omlA. Expression of omlA was constitutive regardless of growth phase, oxygen tension, iron concentration, pH, and temperature. OmlA contained a signal sequence typical of bacterial lipoproteins, with a cysteine as a putative cleavage and lipid attachment site. Inhibition of signal peptidase II by globomycin resulted in failure to process OmlA, thus giving strong evidence that OmlA is a lipoprotein. Cell fractionation followed by Western blot analysis indicated that all OmlA protein is localized in the outer membrane. Mature OmlA was an acidic (pI = 4. 5) protein of 17.3 kDa and had close to 40% amino acid sequence identity to SmpA (small protein A) of Escherichia coli, Vibrio cholerae, and Haemophilus influenzae, a protein of unknown function. All P. aeruginosa strains tested as well as Pseudomonas fluorescens were found to produce OmlA. A mutant strain with impaired production of OmlA but no change in the expression of the overlapping fur gene was constructed. The omlA mutant was hypersusceptible to anionic detergents such as sodium dodecyl sulfate and deoxycholate, and it showed increased susceptibility to various antibiotics, including nalidixic acid, rifampin, novobiocin, and chloramphenicol. A structural role of OmlA in maintaining the cell envelope integrity is proposed.
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Affiliation(s)
- U A Ochsner
- Department of Microbiology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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15
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Abstract
Pseudomonas aeruginosa is one of the most important opportunistic bacterial pathogens in humans and animals. This organism is ubiquitous and has high intrinsic resistance to antibiotics due to the low permeability of the outer membrane and the presence of numerous multiple drug efflux pumps. Various cell-associated and secreted antigens of P. aeruginosa have been the subject of vaccine development. Among pseudomonas antigens, the mucoid substance, which is an extracellular slime consisting predominantly of alginate, was found to be heterogenous in terms of size and immunogenicity. High molecular mass alginate components (30-300 kDa) appear to contain conserved epitopes while lower molecular mass alginate components (10-30 kDa) possess conserved epitopes in addition to unique epitopes. Surface-exposed antigens including O-antigens (O-specific polysaccharide of LPS) or H-antigens (flagellar antigens) have been used for serotyping due to their highly immunogenic nature. Chemical structures of repeating units of O-specific polysaccharides have been elucidated and these data allowed the identification of 31 chemotypes of P. aeruginosa. Conserved epitopes among all serotypes of P. aeruginosa are located in the core oligosaccharide and the lipid A region of LPS and immunogens containing these epitopes induce cross-protective immunity in mice against different P. aeruginosa immunotypes. To examine the protective properties of OM proteins, a vaccine containing P. aeruginosa OM proteins of molecular masses ranging from 20 to 100 kDa has been used in pre-clinical and clinical trials. This vaccine was efficacious in animal models against P. aeruginosa challenge and induced high levels of specific antibodies in human volunteers. Plasma from human volunteers containing anti-P. aeruginosa antibodies provided passive protection and helped the recovery of 87% of patients with severe forms of P. aeruginosa infection. Vaccines prepared from P. aeruginosa ribosomes induced protective immunity in mice, but the efficacy of ribosomal vaccines in humans is not yet known. A number of recent studies indicated the potential of some P. aeruginosa antigens that deserve attention as new vaccine candidates. The outer core of LPS was implicated to be a ligand for binding of P. aeruginosa to airway and ocular epithelial cells of animals. However, heterogeneity exists in this outer core region among different serotypes. Epitopes in the inner core are highly conserved and it has been demonstrated to be surface-accessible, and not masked by O-specific polysaccharide. The use of an in vivo selection/expression technology (IVET) by a group of researchers identified a number of P. aeruginosa proteins that are expressed in vivo and essential for virulence. Two of these in vivo-expressed proteins are FptA (ferripyochelin receptor protein) and a homologue of an LPS biosynthetic enzyme. Our laboratory has identified a highly conserved protein, WbpM, and P. aeruginosa with a deficiency in this protein produces only rough LPS and became serum sensitive. Results from these studies have provided the foundation for a variety of vaccine formulations.
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Affiliation(s)
- E S Stanislavsky
- Mechinkov Research Institute for Vaccines and Sera, Moscow, Russia
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16
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Rehm BH, Hancock RE. Membrane topology of the outer membrane protein OprH from Pseudomonas aeruginosa: PCR-mediated site-directed insertion and deletion mutagenesis. J Bacteriol 1996; 178:3346-9. [PMID: 8655519 PMCID: PMC178091 DOI: 10.1128/jb.178.11.3346-3349.1996] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The 21-kDa outer membrane protein OprH from Pseudomonas aeruginosa is overexpressed under Mg2+ starvation conditions and when overproduced causes resistance to polymyxin B, gentamicin, and EDTA. By circular dichroism analysis, OprH revealed a calculated beta-sheet structure content of 47.3%. PCR-based site-directed deletion and epitope insertion mutagenesis was used to test a topological model of OprH as an eight-stranded beta-barrel. Three permissive and seven nonpermissive malarial epitope insertion mutants and four permissive and four nonpermissive deletion mutants confirmed the general accuracy of this model. Thus, OprH is the smallest outer membrane protein to date to be confirmed as a beta-stranded protein.
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Affiliation(s)
- B H Rehm
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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17
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Liao X, Charlebois I, Ouellet C, Morency MJ, Dewar K, Lightfoot J, Foster J, Siehnel R, Schweizer H, Lam JS, Hancock REW, Levesque RC. Physical mapping of 32 genetic markers on the Pseudomonas aeruginosa PAO1 chromosome. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 1):79-86. [PMID: 8581173 DOI: 10.1099/13500872-142-1-79] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Pseudomonas aeruginosa chromosome was fractionated with the enzymes SpeI and DpnI, and genomic fragments were separated by PFGE and used for mapping a collection of 40 genes. This permitted the localization of 8 genes previously mapped and of 32 genes which had not been mapped. We showed that a careful search of databases and identification of sequences that were homologous to known genes could be used to design and synthesize DNA probes for the mapping of P. aeruginosa homologues by Southern hybridization with genomic fragments, resulting in definition of the locations of the aro-2, dapB, envA, mexA, groEL, oprH, oprM, oprP, ponA, rpoB and rpoH genetic markers. In addition, a combination of distinct DNA sources were utilized as radioactively labelled probes, including specific restriction fragments of the cloned genes (glpD, opdE, oprH, oprO, oprP, phoS), DNA fragments prepared by PCR, and single-stranded DNA prepared from phagemid libraries that had been randomly sequenced. We used a PCR approach to clone fragments of the putative yhhF, sucC, sucD, cypH, pbpB, murE, pbpC, soxR, ftsA, ftsZ and envA genes. Random sequencing of P. aeruginosa DNA from phagemid libraries and database searching permitted the cloning of sequences from the acoA, catR, hemD, pheS, proS, oprD, pyo and rpsB gene homologues. The described genomic methods permit the rapid mapping of the P. aeruginosa genome without linkage analysis.
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MESH Headings
- Base Sequence
- Chromosomes, Bacterial/genetics
- Cloning, Molecular
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- DNA, Complementary/genetics
- Deoxyribonucleases, Type II Site-Specific/metabolism
- Electrophoresis, Gel, Pulsed-Field
- Gene Expression
- Genes, Bacterial
- Genetic Markers
- Molecular Sequence Data
- Oligonucleotide Probes
- Polymerase Chain Reaction
- Pseudomonas aeruginosa/genetics
- Restriction Mapping
- Sequence Analysis, DNA
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Affiliation(s)
- Xiaowen Liao
- Department of Microbiology and Immunology, University of British Columbia, 300-6174 University Boulevard, Vancouver BC, Canada V6T 1Z3
| | - Isabelle Charlebois
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
| | - Catherine Ouellet
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
| | - Marie-Josée Morency
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
| | - Ken Dewar
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
| | - Jeff Lightfoot
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
| | - Jennifer Foster
- Department of Microbiology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Richard Siehnel
- Department of Microbiology and Immunology, University of British Columbia, 300-6174 University Boulevard, Vancouver BC, Canada V6T 1Z3
| | - Herbert Schweizer
- Department of Medical Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Joseph S Lam
- Department of Microbiology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Robert E W Hancock
- Department of Microbiology and Immunology, University of British Columbia, 300-6174 University Boulevard, Vancouver BC, Canada V6T 1Z3
| | - Roger C Levesque
- Microbiologie Moléculaire et Génie des Protéines, Département de Microbiologie, Faculté de Médecine, Pavillon Charles-Eugène-Marchand, Université Laval, Ste-Foy, Québec, Canada G1K 7P4
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18
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Liao X, Hancock RE. Cloning and characterization of the Pseudomonas aeruginosa pbpB gene encoding penicillin-binding protein 3. Antimicrob Agents Chemother 1995; 39:1871-4. [PMID: 7486937 PMCID: PMC162844 DOI: 10.1128/aac.39.8.1871] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Clones containing the pbpB gene which encodes penicillin-binding protein (PBP) 3 of Pseudomonas aeruginosa were detected by hybridization by PCR amplification with primers based on the conserved sequences of high-molecular-weight PBPs. The translated amino acid sequence demonstrated 45% identity and had a total of 66% conserved amino acids relative to the Escherichia coli PBP3. The pbpB gene was located upstream of a gene homologous to the E. coli murE gene, which encodes uridine diphosphate-N-acetyl muramic acid-tripeptide synthetase. The overexpressed pbpB gene product reacted with 3H-penicillin G and had an apparent molecular weight of 60,000.
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Affiliation(s)
- X Liao
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
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19
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Allen NE. Biochemical mechanisms of resistance to non-cell wall antibacterial agents. PROGRESS IN MEDICINAL CHEMISTRY 1995; 32:157-238. [PMID: 8577918 DOI: 10.1016/s0079-6468(08)70454-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- N E Allen
- Infectious Disease Research, Eli Lilly and Company, Indianapolis, IN 46285, USA
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20
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Gromiha MM, Ponnuswamy PK. Prediction of transmembrane beta-strands from hydrophobic characteristics of proteins. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1993; 42:420-31. [PMID: 8106193 DOI: 10.1111/j.1399-3011.1993.tb00149.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The assembly of outer-membrane proteins consisting of beta-strands as transmembrane segments is somewhat more complex when compared to the assembly of inner membrane proteins having alpha-helices as transmembrane parts. This is probably due to the difference in the amino acid sequences of the transmembrane part strands and helices. Because of this feature, most predictive schemes which are successful in predicting transmembrane helical segments fail to predict transmembrane strand segments. Here we propose a new predictive scheme for forecasting the transmembrane strand segments in outer-membrane proteins with the use of the general surrounding hydrophobicity scale developed both for the globular and membrane proteins in the preceding article. Two major features of the scheme are (i) that it does not solely depend on the amphipathic character of a sequence segment while identifying it as a transmembrane strand, and it is capable of predicting strands in varied lengths, a facility to reflect the variation in the membrane surfaces. This scheme predicts the transmembrane beta-strands in porin from R. capsulatus at 76% accuracy (giving due weights to over- and under-predictions when compared to X-ray results). The predicted beta-structure contents in OmpA, porin from E. coli and maltoporin compared with the Raman spectroscopic results at 95% level. These accuracy levels are far superior than the levels obtained from other existing methods. Apart from the above four proteins for which experimental informations are available, ten other outer-membrane proteins, for which there is no information about their secondary structure, are considered in the forecast. The results are analysed and the common features in the folds of the set of fourteen outer-membrane proteins are deduced.
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Affiliation(s)
- M M Gromiha
- Department of Physics, Bharathidasan University, Tiruchirapalli, Tamil Nadu, India
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21
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Yamano Y, Nishikawa T, Komatsu Y. Cloning and nucleotide sequence of anaerobically induced porin protein E1 (OprE) of Pseudomonas aeruginosa PAO1. Mol Microbiol 1993; 8:993-1004. [PMID: 8394980 DOI: 10.1111/j.1365-2958.1993.tb01643.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The porin oprE gene of Pseudomonas aeruginosa PAO1 was isolated. Its nucleotide sequence indicated that the structural gene of 1383 nucleotide residues encodes a precursor consisting of 460 amino acid residues with a signal peptide of 29 amino acid residues, which was confirmed by the N-terminal 23-amino-acid sequence and the reaction with anti-OprE polyclonal antiserum. Anaerobiosis induced OprE production at the transcription level. The transcription start site was determined to be 40 nucleotides upstream from the ATG initiation codon. The control region contained an appropriately situated E sigma 54 recognition site and the putative second half of an ANR box. The amino acid sequence of OprE had some clusters of sequence homologous with that of OprD of P. aeruginosa, which might be responsible for the outer membrane permeability of imipenem and basic amino acids.
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Affiliation(s)
- Y Yamano
- Kanzakigawa Laboratory, Shionogi Research Laboratories, Shionogi & Co., Ltd, Osaka, Japan
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22
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Young M, Hancock RE. Fluoroquinolone supersusceptibility mediated by outer membrane protein OprH overexpression in Pseudomonas aeruginosa: evidence for involvement of a nonporin pathway. Antimicrob Agents Chemother 1992; 36:2365-9. [PMID: 1336943 PMCID: PMC284336 DOI: 10.1128/aac.36.11.2365] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Overexpression of Pseudomonas aeruginosa outer membrane protein OprH led to an 8- to 32-fold increase in susceptibility to chloramphenicol and the quinolones nalidixic acid, norfloxacin, ciprofloxacin, and fleroxacin in comparison with the susceptibility of the wild-type strain H103 grown on Mg(2+)-sufficient medium. This was true regardless of whether OprH overexpression was induced by growth of strain H103 on Mg(2+)-deficient medium, the addition of 5 mM m-toluate to cells containing the cloned oprH gene behind the inducible tol promoter in plasmid pGB25, or mutation in the polymyxin-resistant derivative strain H181. In contrast, OprH overexpression failed to reverse the quinolone resistance phenotype of a nalB mutant. OprH was purified to homogeneity by selective detergent solubilization and fast protein liquid chromatography. The addition of OprH to the solution bathing a black lipid bilayer membrane failed to give rise to an increase in membrane conductance. This suggests that OprH is not a porin but, instead, may cause increased uptake of quinolones and chloramphenicol via a non-porin pathway.
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Affiliation(s)
- M Young
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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23
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Young ML, Bains M, Bell A, Hancock RE. Role of Pseudomonas aeruginosa outer membrane protein OprH in polymyxin and gentamicin resistance: isolation of an OprH-deficient mutant by gene replacement techniques. Antimicrob Agents Chemother 1992; 36:2566-8. [PMID: 1336952 PMCID: PMC284378 DOI: 10.1128/aac.36.11.2566] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The cloned oprH gene of Pseudomonas aeruginosa was mutated by inserting a 1.4-kbp fragment that encodes tetracycline resistance. This mutated gene was then incorporated into the P. aeruginosa chromosome by homologous recombination. Growth of the resultant oprH::tet mutant in Mg(2+)-deficient medium had little effect on susceptibility to polymyxin B, gentamicin, or EDTA unless the mutant was complemented by the cloned oprH gene in plasmid pGB25. In contrast, growth of the parent strain on Mg(2+)-deficient medium resulted in resistance to all three agents. These data support the hypothesis that overexpression of OprH under Mg(2+)-deficient growth conditions is conditionally required for resistance to these three agents.
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Affiliation(s)
- M L Young
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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24
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Huang H, Siehnel RJ, Bellido F, Rawling E, Hancock RE. Analysis of two gene regions involved in the expression of the imipenem-specific, outer membrane porin protein OprD ofPseudomonas aeruginosa. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05474.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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25
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Bell A, Bains M, Hancock RE. Pseudomonas aeruginosa outer membrane protein OprH: expression from the cloned gene and function in EDTA and gentamicin resistance. J Bacteriol 1991; 173:6657-64. [PMID: 1938872 PMCID: PMC209012 DOI: 10.1128/jb.173.21.6657-6664.1991] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Overexpression of major outer membrane protein OprH of Pseudomonas aeruginosa as a result of mutation (in strain H181) or adaptation to low Mg2+ concentrations (in parent strain H103) is accompanied by increased resistance to polymyxin B, gentamicin, and EDTA. A 2.8-kb EcoRI fragment containing the oprH gene was subcloned into several different expression plasmids in Escherichia coli. These experiments showed that significant levels of OprH could be produced from a promoter on the EcoRI fragment; that the cloned oprH gene was not regulated by Mg2+ deficiency; that there were no differences in the expression of OprH in any construction, regardless of whether the gene from strain H103 or its OprH-overexpressing, polymyxin B-resistant derivative, strain H181, was used; and that overexpression of OprH in E. coli to the level observed in P. aeruginosa H181 did not result in a resistance phenotype. These results favored the conclusion that the mutation in strain H181 was a regulatory rather than a promoter mutation. The oprH gene was cloned behind the benzoate-inducible pm promoter in plasmid pGB25 and transferred to P. aeruginosa H103. Overexpression of OprH from the cloned gene in H103/pGB25 resulted in EDTA resistance but not polymyxin B resistance. This result suggested that another factor, possibly lipopolysaccharide, was affected by the mutation in strain H181. Consistent with this suggestion was the demonstration that mutants of strain H181 with alterations in lipopolysaccharide had reverted to wild-type polymyxin B susceptibility but had unaltered gentamicin and EDTA resistance. These data were consistent with the hypothesis that OprH replaces outer membrane-stabilizing divalent cations.
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Affiliation(s)
- A Bell
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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26
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Mot R, Vanderleyden J. Purification of a root-adhesive outer membrane protein of root-colonizingPseudomonas fluorescens. FEMS Microbiol Lett 1991. [DOI: 10.1111/j.1574-6968.1991.tb04780.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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27
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Struyvé M, Moons M, Tommassen J. Carboxy-terminal phenylalanine is essential for the correct assembly of a bacterial outer membrane protein. J Mol Biol 1991; 218:141-8. [PMID: 1848301 DOI: 10.1016/0022-2836(91)90880-f] [Citation(s) in RCA: 385] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial outer membrane proteins are supposed to span the membrane repeatedly, mostly in the form of amphipathic beta-sheets. The last ten C-terminal amino acid residues of PhoE protein are supposed to form such a membrane-spanning segment. Deletion of this segment completely prevents incorporation into the outer membrane. Comparison of the last ten amino acid residues of other outer membrane proteins from different Gram-negative bacteria revealed the presence of a potential amphipathic beta-sheet with hydrophobic residues at positions 1 (Phe), 3 (preferentially Tyr), 5, 7 and 9 from the C terminus, in the vast majority of these proteins. Since such sequences were not detected at the C termini of periplasmic proteins, it appears to be possible to discriminate between the majority of outer membrane proteins and periplasmic proteins on the basis of sequence data. The highly conserved phenylalanine at the C termini of outer membrane proteins suggests an important function for this amino acid in assembly into the outer membrane. Site-directed mutagenesis was applied to study the role of the C-terminal Phe in PhoE protein assembly. All mutant proteins were correctly incorporated into the outer membrane to some extent, but the efficiency of the process was severely affected. It appears that both the hydrophobicity and the aromatic nature of Phe are of importance.
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Affiliation(s)
- M Struyvé
- Department of Molecular Cell Biology, University of Utrecht, The Netherlands
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28
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Ullstrom CA, Siehnel R, Woodruff W, Steinbach S, Hancock RE. Conservation of the gene for outer membrane protein OprF in the family Pseudomonadaceae: sequence of the Pseudomonas syringae oprF gene. J Bacteriol 1991; 173:768-75. [PMID: 1898935 PMCID: PMC207070 DOI: 10.1128/jb.173.2.768-775.1991] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The conservation of the oprF gene for the major outer membrane protein OprF was determined by restriction mapping and Southern blot hybridization with the Pseudomonas aeruginosa oprF gene as a probe. The restriction map was highly conserved among 16 of the 17 serotype strains and 42 clinical isolates of P. aeruginosa. Only the serotype 12 isolate and one clinical isolate showed small differences in restriction pattern. Southern probing of PstI chromosomal digests of 14 species from the family Pseudomonadaceae revealed that only the nine members of rRNA homology group I hybridized with the oprF gene. To reveal the actual extent of homology, the oprF gene and its product were characterized in Pseudomonas syringae. Nine strains of P. syringae from seven different pathovars hybridized with the P. aeruginosa gene to produce five different but related restriction maps. All produced an OprF protein in their outer membranes with the same apparent molecular weight as that of P.aeruginosa OprF. In each case the protein reacted with monoclonal antibody MA4-10 and was similarly heat and 2-mercaptoethanol modifiable. The purified OprF protein of the type strain P. syringae pv. syringae ATCC 19310 reconstituted small channels in lipid bilayer membranes. The oprF gene from this latter strain was cloned and sequenced. Despite the low level of DNA hybridization between P. aeruginosa and P. syringae DNA, the OprF gene was highly conserved between the species with 72% DNA sequence identity and 68% amino acid sequence identity overall. The carboxy terminus-encoding region of P. syringae oprF showed 85 and 33% identity, respectively, with the same regions of the P. aeruginosa oprF and Escherichia coli ompA genes.
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Affiliation(s)
- C A Ullstrom
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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29
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Kelly-Wintenberg K, Anderson T, Montie TC. Phosphorylated tyrosine in the flagellum filament protein of Pseudomonas aeruginosa. J Bacteriol 1990; 172:5135-9. [PMID: 1697577 PMCID: PMC213172 DOI: 10.1128/jb.172.9.5135-5139.1990] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Purified flagella from two strains of 32P-labeled Pseudomonas aeruginosa were shown to be phosphorylated. This was confirmed by autoradiography of flagellin protein in polyacrylamide gels. Thin-layer electrophoresis and autoradiography of flagellin partial hydrolysates indicated that phosphotyrosine was the major phosphorylated amino acid. High-pressure liquid chromatographic analysis confirmed the presence of phosphotyrosine in flagellum filament protein. Preliminary data indicated that less than one tyrosine per subunit was phosphorylated. No evidence was found for phosphorylation of serine or threonine. A function related to tyrosine phosphorylation has not been determined.
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Abstract
In this review, we describe the outer membrane proteins of Pseudomonas aeruginosa and related strains from the Pseudomonas fluorescens rRNA homology group of the Pseudomonadaceae, with emphasis on the physiological function and biochemical characteristics of these proteins. The use of opr (for outer membrane protein) is proposed as the genetic designation for the P. aeruginosa outer membrane proteins and letters are assigned, in conjunction with this designation, to known outer membrane proteins. Proteins whose primary functions involve pore formation, transport of specific substrates, cell structure determination and membrane stabilization are discussed. The conservation of selected proteins in the above Pseudomonas species is also examined.
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Affiliation(s)
- R E Hancock
- Department of Microbiology, University of British Columbia, Vancouver, Canada
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31
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New nucleotide sequence data on the EMBL File Server. Nucleic Acids Res 1989; 17:7553-78. [PMID: 2798119 PMCID: PMC334862 DOI: 10.1093/nar/17.18.7553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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