1
|
Wang S, Jiang L, Cui L, Alain K, Xie S, Shao Z. Transcriptome Analysis of Cyclooctasulfur Oxidation and Reduction by the Neutrophilic Chemolithoautotrophic Sulfurovum indicum from Deep-Sea Hydrothermal Ecosystems. Antioxidants (Basel) 2023; 12:antiox12030627. [PMID: 36978876 PMCID: PMC10045233 DOI: 10.3390/antiox12030627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
Chemolithoautotrophic Campylobacterota are widespread and predominant in worldwide hydrothermal vents, and they are key players in the turnover of zero-valence sulfur. However, at present, the mechanism of cyclooctasulfur activation and catabolism in Campylobacterota bacteria is not clearly understood. Here, we investigated these processes in a hydrothermal vent isolate named Sulfurovum indicum ST-419. A transcriptome analysis revealed that multiple genes related to biofilm formation were highly expressed during both sulfur oxidation and reduction. Additionally, biofilms containing cells and EPS coated on sulfur particles were observed by SEM, suggesting that biofilm formation may be involved in S0 activation in Sulfurovum species. Meanwhile, several genes encoding the outer membrane proteins of OprD family were also highly expressed, and among them, gene IMZ28_RS00565 exhibited significantly high expressions by 2.53- and 7.63-fold changes under both conditions, respectively, which may play a role in sulfur uptake. However, other mechanisms could be involved in sulfur activation and uptake, as experiments with dialysis bags showed that direct contact between cells and sulfur particles was not mandatory for sulfur reduction activity, whereas cell growth via sulfur oxidation did require direct contact. This indirect reaction could be ascribed to the role of H2S and/or other thiol-containing compounds, such as cysteine and GSH, which could be produced in the culture medium during sulfur reduction. In the periplasm, the sulfur-oxidation-multienzyme complexes soxABXY1Z1 and soxCDY2Z2 are likely responsible for thiosulfate oxidation and S0 oxidation, respectively. In addition, among the four psr gene clusters encoding polysulfide reductases, only psrA3B3C3 was significantly upregulated under the sulfur reduction condition, implying its essential role in sulfur reduction. These results expand our understanding of the interactions of Campylobacterota with the zero-valence sulfur and their adaptability to deep-sea hydrothermal environments.
Collapse
Affiliation(s)
- Shasha Wang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
- Sino-French Laboratory of Deep-Sea Microbiology (MicrobSea), Xiamen 361005, China
| | - Lijing Jiang
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
- Sino-French Laboratory of Deep-Sea Microbiology (MicrobSea), Xiamen 361005, China
- Correspondence: (L.J.); (Z.S.)
| | - Liang Cui
- Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen 361021, China
| | - Karine Alain
- CNRS, Université Brest, Ifremer, Unité Biologie et Ecologie des Ecosystèmes Marins Profonds BEEP, UMR 6197, IRP 1211 MicrobSea, IUEM, Rue Dumont d’Urville, F-29280 Plouzané, France
| | - Shaobin Xie
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
- Sino-French Laboratory of Deep-Sea Microbiology (MicrobSea), Xiamen 361005, China
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
- Sino-French Laboratory of Deep-Sea Microbiology (MicrobSea), Xiamen 361005, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
- Correspondence: (L.J.); (Z.S.)
| |
Collapse
|
2
|
Interplay of OpdP Porin and Chromosomal Carbapenemases in the Determination of Carbapenem Resistance/Susceptibility in Pseudomonas aeruginosa. Microbiol Spectr 2021; 9:e0118621. [PMID: 34585948 PMCID: PMC8557820 DOI: 10.1128/spectrum.01186-21] [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] [Indexed: 12/12/2022] Open
Abstract
Carbapenem resistance in Pseudomonas aeruginosa strains responsible for chronic lung infections in cystic fibrosis (CF) patients is mainly due to loss of the OprD protein and, limited to meropenem and doripenem, to overexpression of efflux pumps. However, recent reports of isolates showing inconsistent genotype-phenotype combinations (e.g., susceptibility in the presence of resistance determinants and vice versa) suggest the involvement of additional factors whose role is not yet fully elucidated. Among them, the OpdP porin as an alternative route of entry for carbapenems other than OprD and the overexpression of two chromosomal carbapenemases, the Pseudomonas-derived cephalosporinase (PDC) and the PoxB oxacillinase, have recently been reconsidered and studied in specific model strains. Here, the contribution of these factors was investigated by comparing different phenotypic variants of three strains collected from the sputum of colonized CF patients. Carbapenem uptake through OpdP was investigated both at the functional level, by assessing the competition exerted by glycine-glutamate, the OpdP’s natural substrate, against imipenem uptake, and at the molecular level, by comparing the expression levels of opdP genes by quantitative real-time PCR (qRT-PCR). Moreover, overexpression of the chromosomal carbapenemases in some of the isolates was also investigated by qRT-PCR. The results showed that, even if OprD inactivation remains the most important determinant of carbapenem resistance in strains infecting the CF lung, the interplay of other determinants might have a nonnegligible impact on bacterial susceptibility, being able to modify the phenotype of part of the population and consequently complicating the choice of an appropriate therapy. IMPORTANCE This study examines the interplay of multiple factors in determining a pattern of resistance or susceptibility to carbapenems in clinical isolates of Pseudomonas aeruginosa, focusing on the role of previously poorly understood determinants. In particular, the impact of carbapenem permeability through OprD and OpdP porins was analyzed, as well as the activity of the chromosomal carbapenemases AmpC and PoxB, going beyond the simple identification of resistance determinants encoded by each isolate. Indeed, analysis of the expression levels of these determinants provides a new approach to determine the contribution of each factor, both individually and in coexistence with the other factors. The study contributes to understanding some phenotype-genotype discordances closely related to the heteroresistance frequently detected in P. aeruginosa isolates responsible for pulmonary infections in cystic fibrosis patients, which complicates the choice of an appropriate patient-specific therapy.
Collapse
|
3
|
Sonnleitner E, Pusic P, Wolfinger MT, Bläsi U. Distinctive Regulation of Carbapenem Susceptibility in Pseudomonas aeruginosa by Hfq. Front Microbiol 2020; 11:1001. [PMID: 32528439 PMCID: PMC7264166 DOI: 10.3389/fmicb.2020.01001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/24/2020] [Indexed: 12/29/2022] Open
Abstract
Carbapenems are often the antibiotics of choice to combat life threatening infections caused by the opportunistic human pathogen Pseudomonas aeruginosa. The outer membrane porins OprD and OpdP serve as entry ports for carbapenems. Here, we report that the RNA chaperone Hfq governs post-transcriptional regulation of the oprD and opdP genes in a distinctive manner. Hfq together with the recently described small regulatory RNAs (sRNAs) ErsA and Sr0161 is shown to mediate translational repression of oprD, whereas opdP appears not to be regulated by sRNAs. At variance, our data indicate that opdP is translationally repressed by a regulatory complex consisting of Hfq and the catabolite repression protein Crc, an assembly known to be key to carbon catabolite repression in P. aeruginosa. The regulatory RNA CrcZ, which is up-regulated during growth of P. aeruginosa on less preferred carbon sources, is known to sequester Hfq, which relieves Hfq-mediated translational repression of genes. The differential carbapenem susceptibility during growth on different carbon sources can thus be understood in light of Hfq-dependent oprD/opdP regulation and of the antagonizing function of the CrcZ RNA on Hfq regulatory complexes.
Collapse
Affiliation(s)
- Elisabeth Sonnleitner
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Vienna BioCenter (VBC), University of Vienna, Vienna, Austria
| | - Petra Pusic
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Vienna BioCenter (VBC), University of Vienna, Vienna, Austria
| | - Michael T Wolfinger
- Department of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.,Research Group Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, Vienna, Austria
| | - Udo Bläsi
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, Vienna BioCenter (VBC), University of Vienna, Vienna, Austria
| |
Collapse
|
4
|
Khaledi A, Weimann A, Schniederjans M, Asgari E, Kuo TH, Oliver A, Cabot G, Kola A, Gastmeier P, Hogardt M, Jonas D, Mofrad MR, Bremges A, McHardy AC, Häussler S. Predicting antimicrobial resistance in Pseudomonas aeruginosa with machine learning-enabled molecular diagnostics. EMBO Mol Med 2020; 12:e10264. [PMID: 32048461 PMCID: PMC7059009 DOI: 10.15252/emmm.201910264] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 12/24/2019] [Accepted: 01/09/2020] [Indexed: 12/20/2022] Open
Abstract
Limited therapy options due to antibiotic resistance underscore the need for optimization of current diagnostics. In some bacterial species, antimicrobial resistance can be unambiguously predicted based on their genome sequence. In this study, we sequenced the genomes and transcriptomes of 414 drug‐resistant clinical Pseudomonas aeruginosa isolates. By training machine learning classifiers on information about the presence or absence of genes, their sequence variation, and expression profiles, we generated predictive models and identified biomarkers of resistance to four commonly administered antimicrobial drugs. Using these data types alone or in combination resulted in high (0.8–0.9) or very high (> 0.9) sensitivity and predictive values. For all drugs except for ciprofloxacin, gene expression information improved diagnostic performance. Our results pave the way for the development of a molecular resistance profiling tool that reliably predicts antimicrobial susceptibility based on genomic and transcriptomic markers. The implementation of a molecular susceptibility test system in routine microbiology diagnostics holds promise to provide earlier and more detailed information on antibiotic resistance profiles of bacterial pathogens and thus could change how physicians treat bacterial infections.
Collapse
Affiliation(s)
- Ariane Khaledi
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Molecular Bacteriology Group, TWINCORE-Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Aaron Weimann
- Molecular Bacteriology Group, TWINCORE-Centre for Experimental and Clinical Infection Research, Hannover, Germany.,Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Monika Schniederjans
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Molecular Bacteriology Group, TWINCORE-Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Ehsaneddin Asgari
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Tzu-Hao Kuo
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Antonio Oliver
- Servicio de Microbiología y Unidad de Investigación Hospital Universitario Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISPa), Palma de Mallorca, Spain
| | - Gabriel Cabot
- Servicio de Microbiología y Unidad de Investigación Hospital Universitario Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISPa), Palma de Mallorca, Spain
| | - Axel Kola
- Institute of Hygiene and Environmental Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Petra Gastmeier
- Institute of Hygiene and Environmental Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Hogardt
- Institute of Medical Microbiology and Infection Control, University Hospital Frankfurt, Frankfurt/Main, Germany
| | - Daniel Jonas
- Faculty of Medicine, Institute for Infection Prevention and Hospital Epidemiology, Medical Center-University of Freiburg, Freiburg, Germany
| | - Mohammad Rk Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | - Andreas Bremges
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Alice C McHardy
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Molecular Bacteriology Group, TWINCORE-Centre for Experimental and Clinical Infection Research, Hannover, Germany
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Soundararajan G, Bhamidimarri SP, Winterhalter M. Understanding Carbapenem Translocation through OccD3 (OpdP) of Pseudomonas aeruginosa. ACS Chem Biol 2017; 12:1656-1664. [PMID: 28440622 DOI: 10.1021/acschembio.6b01150] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pseudomonas aeruginosa utilizes a plethora of substrate specific channels for the uptake of small nutrients. OccD3 (OpdP or PA4501) is an OprD-like arginine uptake channel of P. aeruginosa whose role has been implicated in carbapenem uptake. To understand the mechanism of selective permeation, we reconstituted single OccD3 channels in a planar lipid bilayer and characterized the interaction with Imipenem and Meropenem, analyzing the ion current fluctuation in the presence of substrates. We performed point mutations in the constriction region of OccD3 to understand the binding and translocation of antibiotic in OccD3. By mutating two key residues in the substrate binding sites of OccD3 (located in the internal loop L7 and basic ladder), we emphasize the importance of these residues. We show that carbapenem antibiotics follow a similar path as arginine through the constriction zone and the basic ladder to translocate across OccD3.
Collapse
Affiliation(s)
- Gowrishankar Soundararajan
- Department of Life Sciences
and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | | | - Mathias Winterhalter
- Department of Life Sciences
and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| |
Collapse
|
7
|
Iyer R, Sylvester MA, Velez-Vega C, Tommasi R, Durand-Reville TF, Miller AA. Whole-Cell-Based Assay To Evaluate Structure Permeation Relationships for Carbapenem Passage through the Pseudomonas aeruginosa Porin OprD. ACS Infect Dis 2017; 3:310-319. [PMID: 28157293 DOI: 10.1021/acsinfecdis.6b00197] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The global emergence of antibiotic resistance, especially in Gram-negative bacteria, is an urgent threat to public health. Discovery of novel classes of antibiotics with activity against these pathogens has been impeded by a fundamental lack of understanding of the molecular drivers underlying small molecule uptake. Although it is well-known that outer membrane porins represent the main route of entry for small, hydrophilic molecules across the Gram-negative cell envelope, the structure-permeation relationship for porin passage has yet to be defined. To address this knowledge gap, we developed a sensitive and specific whole-cell approach in Escherichia coli called titrable outer membrane permeability assay system (TOMAS). We used TOMAS to characterize the structure porin-permeation relationships of a set of novel carbapenem analogues through the Pseudomonas aeruginosa porin OprD. Our results show that small structural modifications, especially the number and nature of charges and their position, have dramatic effects on the ability of these molecules to permeate cells through OprD. This is the first demonstration of a defined relationship between specific molecular changes in a substrate and permeation through an isolated porin. Understanding the molecular mechanisms that impact antibiotic transit through porins should provide valuable insights to antibacterial medicinal chemistry and may ultimately allow for the rational design of porin-mediated uptake of small molecules into Gram-negative bacteria.
Collapse
Affiliation(s)
- Ramkumar Iyer
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Mark A. Sylvester
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Camilo Velez-Vega
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Ruben Tommasi
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | | | - Alita A. Miller
- Entasis Therapeutics, Inc., 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| |
Collapse
|
8
|
Chalhoub H, Pletzer D, Weingart H, Braun Y, Tunney MM, Elborn JS, Rodriguez-Villalobos H, Plésiat P, Kahl BC, Denis O, Winterhalter M, Tulkens PM, Van Bambeke F. Mechanisms of intrinsic resistance and acquired susceptibility of Pseudomonas aeruginosa isolated from cystic fibrosis patients to temocillin, a revived antibiotic. Sci Rep 2017; 7:40208. [PMID: 28091521 PMCID: PMC5238406 DOI: 10.1038/srep40208] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/01/2016] [Indexed: 12/29/2022] Open
Abstract
The β-lactam antibiotic temocillin (6-α-methoxy-ticarcillin) shows stability to most extended spectrum β-lactamases, but is considered inactive against Pseudomonas aeruginosa. Mutations in the MexAB-OprM efflux system, naturally occurring in cystic fibrosis (CF) isolates, have been previously shown to reverse this intrinsic resistance. In the present study, we measured temocillin activity in a large collection (n = 333) of P. aeruginosa CF isolates. 29% of the isolates had MICs ≤ 16 mg/L (proposed clinical breakpoint for temocillin). Mutations were observed in mexA or mexB in isolates for which temocillin MIC was ≤512 mg/L (nucleotide insertions or deletions, premature termination, tandem repeat, nonstop, and missense mutations). A correlation was observed between temocillin MICs and efflux rate of N-phenyl-1-naphthylamine (MexAB-OprM fluorescent substrate) and extracellular exopolysaccharide abundance (contributing to a mucoid phenotype). OpdK or OpdF anion-specific porins expression decreased temocillin MIC by ~1 two-fold dilution only. Contrarily to the common assumption that temocillin is inactive on P. aeruginosa, we show here clinically-exploitable MICs on a non-negligible proportion of CF isolates, explained by a wide diversity of mutations in mexA and/or mexB. In a broader context, this work contributes to increase our understanding of MexAB-OprM functionality and help delineating how antibiotics interact with MexA and MexB.
Collapse
Affiliation(s)
- Hussein Chalhoub
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Daniel Pletzer
- Life Sciences, School of Engineering and Science, Jacobs University, Bremen, Germany
| | - Helge Weingart
- Life Sciences, School of Engineering and Science, Jacobs University, Bremen, Germany
| | - Yvonne Braun
- Life Sciences, School of Engineering and Science, Jacobs University, Bremen, Germany
| | - Michael M Tunney
- CF &Airways Microbiology Research Group, Queen's University Belfast, Belfast, UK
| | - J Stuart Elborn
- CF &Airways Microbiology Research Group, Queen's University Belfast, Belfast, UK
| | - Hector Rodriguez-Villalobos
- Laboratoire de microbiologie, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium
| | - Patrick Plésiat
- Laboratoire de bactériologie, Hôpital Jean Minjoz, Besançon, France
| | | | - Olivier Denis
- Laboratoire de microbiologie, Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium
| | - Mathias Winterhalter
- Life Sciences, School of Engineering and Science, Jacobs University, Bremen, Germany
| | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| |
Collapse
|
9
|
Chalhoub H, Sáenz Y, Rodriguez-Villalobos H, Denis O, Kahl BC, Tulkens PM, Van Bambeke F. High-level resistance to meropenem in clinical isolates of Pseudomonas aeruginosa in the absence of carbapenemases: role of active efflux and porin alterations. Int J Antimicrob Agents 2016; 48:740-743. [PMID: 28128097 DOI: 10.1016/j.ijantimicag.2016.09.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 08/25/2016] [Accepted: 09/12/2016] [Indexed: 11/29/2022]
Abstract
High-level carbapenem resistance is worryingly increasing in clinical isolates and is often attributed to carbapenemase expression. This study aimed to determine the mechanisms leading to high-level meropenem resistance in six carbapenemase-negative Pseudomonas aeruginosa isolated from cystic fibrosis (CF) patients and seven carbapenemase-positive isolates from patients suffering from hospital-acquired pneumonia (HAP). MICs were determined in the absence or presence of l-arginine or glycine-glutamate as competitive substrates for OprD (OccD1) or OpdP (OccD3), respectively, or the efflux pump inhibitor Phe-Arg β-naphthylamide (PAβN). β-Lactamases were screened by phenotypic tests and/or PCR. The oprD gene and its promoter were sequenced; protein expression was evidenced by SDS-PAGE. mexA, mexX, mexC and mexE transcripts were evaluated by real-time and semiquantitative PCR. Meropenem/imipenem MICs were 64-128/16-32 mg/L and 128/128-256 mg/L in CF and HAP isolates, respectively; PAβN reduced meropenem MICs to 4-16 mg/L only and specifically in CF isolates; porin competitors had no effect on MICs. All isolates showed an increase in transcription levels of mexA, mexX and/or mexC and mutations in oprD leading to production of truncated proteins. AmpC-type cephalosporinases were overexpressed in CF isolates and VIM-2 was expressed in HAP isolates. Antibiotic exclusion from bacteria by concomitant efflux and reduced uptake is sufficient to confer high-level resistance to meropenem in isolates overexpressing AmpC-type cephalosporinases. As efflux is preponderant in these isolates, it confers a paradoxical phenotype where meropenem is less active than imipenem. Concomitant susceptibility testing of both carbapenems and rapid elucidation of the most probable resistance mechanisms is thus warranted.
Collapse
Affiliation(s)
- Hussein Chalhoub
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Yolanda Sáenz
- Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | | | - Olivier Denis
- Laboratoire de microbiologie, Hôpital Erasme, Université libre de Bruxelles, Brussels, Belgium
| | | | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
| |
Collapse
|
10
|
Sarcosine Catabolism in Pseudomonas aeruginosa Is Transcriptionally Regulated by SouR. J Bacteriol 2015; 198:301-10. [PMID: 26503852 DOI: 10.1128/jb.00739-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 10/22/2015] [Indexed: 01/18/2023] Open
Abstract
UNLABELLED Sarcosine (N-methylglycine) is present in many environments inhabited by pseudomonads and is likely most often encountered as an intermediate in the metabolism of choline, carnitine, creatine, and glyphosate. While the enzymology of sarcosine metabolism has been relatively well studied in bacteria, the regulatory mechanisms governing catabolism have remained largely unknown. We previously determined that the sarcosine-catabolic (sox) operon of Pseudomonas aeruginosa is induced by the AraC family regulator GbdR in response to glycine betaine and dimethylglycine. However, induction of these genes was still observed in response to sarcosine in a gbdR deletion mutant, indicating that an independent sarcosine-responsive transcription factor also acted at this locus. Our goal in this study was to identify and characterize this regulator. Using a transposon-based genetic screen, we identified PA4184, or SouR (sarcosine oxidation and utilization regulator), as the sarcosine-responsive regulator of the sox operon, with tight induction specificity for sarcosine. The souR gene is required for appreciable growth on sarcosine as a carbon and nitrogen source. We also characterized the transcriptome response to sarcosine governed by SouR using microarray analyses and performed electrophoretic mobility shift assays to identify promoters directly regulated by the transcription factor. Finally, we characterized PA3630, or GfnR (glutathione-dependent formaldehyde neutralization regulator), as the regulator of the glutathione-dependent formaldehyde detoxification system in P. aeruginosa that is expressed in response to formaldehyde released during the catabolism of sarcosine. This study expands our understanding of sarcosine metabolic regulation in bacteria through the identification and characterization of the first known sarcosine-responsive transcriptional regulator. IMPORTANCE The Pseudomonas aeruginosa genome encodes many diverse metabolic pathways, yet the specific transcription regulators controlling their expression remain mostly unknown. Here, we used a genetic screen to identify the sarcosine-specific regulator of the sarcosine oxidase operon, which we have named SouR. SouR is the first bacterial regulator shown to respond to sarcosine, and it is required for growth on sarcosine. Sarcosine is found in its free form and is also an intermediate in the catabolic pathways of glycine betaine, carnitine, creatine, and glyphosate. The similarity of SouR to the regulators of carnitine and glycine betaine catabolism suggests evolutionary diversification within this regulatory family to allow response to structurally similar but physiologically distinct ligands.
Collapse
|
11
|
Fowler RC, Hanson ND. The OpdQ porin of Pseudomonas aeruginosa is regulated by environmental signals associated with cystic fibrosis including nitrate-induced regulation involving the NarXL two-component system. Microbiologyopen 2015; 4:967-82. [PMID: 26459101 PMCID: PMC4694141 DOI: 10.1002/mbo3.305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/10/2015] [Accepted: 09/17/2015] [Indexed: 12/15/2022] Open
Abstract
Pseudomonas aeruginosa is a versatile opportunistic pathogen that causes chronic infections in immunocompromised hosts. Multiple porins modulate outer membrane permeability under various environmental conditions. The lung environment of cystic fibrosis (CF) patients is unique with changes occurring in nutrient availability, osmolarity, and oxygen content. Although P. aeruginosa gene expression is modified under these conditions, little is known about how they influence porin regulation. In this study, we evaluated the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, with regard to oxygen, nitrate, and/or NaCl levels. We demonstrated using promoter::fusion clones of P. aeruginosa PAO1 and clinical strains collected from CF patients that OpdQ was transcriptionally repressed under low oxygen but increased in the presence of nitrate. The nitrate‐induced regulation of OpdQ was found to be dependent on the transcription factor NarL via the NarXL two‐component system. In addition, NaCl‐induced osmotic stress increased OpdQ production among most of the clinical strains evaluated. In conclusion, these data identify for the first time that specific environmental cues associated with the CF microenvironment influence porin regulation, and that the nitrate‐induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two‐component system of P. aeruginosa.
Collapse
Affiliation(s)
- Randal C Fowler
- Department of Medical Microbiology and Immunology, Center for Research in Anti-Infectives and Biotechnology, Creighton University School of Medicine, 2500 California Plaza, Omaha, Nebraska, 68178
| | - Nancy D Hanson
- Department of Medical Microbiology and Immunology, Center for Research in Anti-Infectives and Biotechnology, Creighton University School of Medicine, 2500 California Plaza, Omaha, Nebraska, 68178
| |
Collapse
|
12
|
Asfahl KL, Walsh J, Gilbert K, Schuster M. Non-social adaptation defers a tragedy of the commons in Pseudomonas aeruginosa quorum sensing. THE ISME JOURNAL 2015; 9:1734-46. [PMID: 25615439 PMCID: PMC4511930 DOI: 10.1038/ismej.2014.259] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 12/04/2014] [Accepted: 12/05/2014] [Indexed: 02/02/2023]
Abstract
In a process termed quorum sensing (QS), the opportunistic bacterial pathogen Pseudomonas aeruginosa uses diffusible signaling molecules to regulate the expression of numerous secreted factors or public goods that are shared within the population. But not all cells respond to QS signals. These social cheaters typically harbor a mutation in the QS receptor gene lasR and exploit the public goods produced by cooperators. Here we show that non-social adaptation under growth conditions that require QS-dependent public goods increases tolerance to cheating and defers a tragedy of the commons. The underlying mutation is in the transcriptional repressor gene psdR. This mutation has no effect on public goods expression but instead increases individual fitness by derepressing growth-limiting intracellular metabolism. Even though psdR mutant populations remain susceptible to invasion by isogenic psdR lasR cheaters, they bear a lower cheater load than do wild-type populations, and they are completely resistant to invasion by lasR cheaters with functional psdR. Mutations in psdR also sustain growth near wild-type levels when paired with certain partial loss-of-function lasR mutations. Targeted sequencing of multiple evolved isolates revealed that mutations in psdR arise before mutations in lasR, and rapidly sweep through the population. Our results indicate that a QS-favoring environment can lead to adaptations in non-social, intracellular traits that increase the fitness of cooperating individuals and thereby contribute to population-wide maintenance of QS and associated cooperative behaviors.
Collapse
Affiliation(s)
- Kyle L Asfahl
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Jessica Walsh
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Kerrigan Gilbert
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| | - Martin Schuster
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
| |
Collapse
|
13
|
Metaproteomic analysis of bacterial communities in marine mudflat aquaculture sediment. World J Microbiol Biotechnol 2015; 31:1397-408. [DOI: 10.1007/s11274-015-1891-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
|
14
|
Tommasi R, Brown DG, Walkup GK, Manchester JI, Miller AA. ESKAPEing the labyrinth of antibacterial discovery. Nat Rev Drug Discov 2015; 14:529-42. [DOI: 10.1038/nrd4572] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
15
|
Liu H, Sun WB, Liang RB, Huang L, Hou JL, Liu JH. iTRAQ-based quantitative proteomic analysis of Pseudomonas aeruginosa SJTD-1: A global response to n-octadecane induced stress. J Proteomics 2015; 123:14-28. [PMID: 25845586 DOI: 10.1016/j.jprot.2015.03.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/14/2015] [Accepted: 03/29/2015] [Indexed: 12/16/2022]
Abstract
UNLABELLED N-octadecane, the shortest solid-state alkane, was efficiently consumed by Pseudomonas aeruginosa SJTD-1. To reveal its mechanism, the iTRAQ-LC-MS/MS strategy was applied for quantification of proteins in response to alkane. As a result, 383 alkane-responsive proteins were identified and these proteins could be linked to multiple biochemical pathways. Above all, the level of alkane hydroxylase AlkB2 has been significantly higher in alkane condition. Also, the presence of a putative novel AlmA-like monooxygenase and its role on alkane hydroxylation were firstly proposed in Pseudomonas. In addition, other proteins for chemotaxic, β-oxidation, glyoxylate bypass, alkane uptake, cross membrane transport, enzymatic steps and the carbon flow may have important roles in the cellular response to alkane. Most of those differently expressed proteins were functionally mapped into pathways of alkane degradation or metabolism thereof. In this sense, findings in this study provide critical clues to reveal biodegradation of long chain n-alkanes and rationally be important for potent biocatalyst for bioremediation in future. BIOLOGICAL SIGNIFICANCE We use iTRAQ strategy firstly to compare the proteomes of Pseudomonas SJTD-1 degrading alkane. Changes in protein clearly provide a comprehensive overview on alkane hydroxylation of SJTD-1, including those proteins for chemotaxis, alkane uptake, cross membrane transport, enzymatic steps and the carbon flow. AlkB2 and a putative novel AlmA-like monooxygenase have been highlighted for their outstanding contribution to alkane use. We found that several chemotaxic proteins were altered in abundance in alkane-grown cells. These results may be helpful for understanding alkane use for Pseudomonas.
Collapse
Affiliation(s)
- Huan Liu
- School of Life Science & Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Wen-Bing Sun
- School of Life Science & Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Ru-Bing Liang
- School of Life Science & Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Li Huang
- Department of Plastic and Aesthetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jing-Li Hou
- Instrumental Analysis Center of Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
| | - Jian-Hua Liu
- School of Life Science & Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
| |
Collapse
|
16
|
Isabella V, Campbell A, Manchester J, Sylvester M, Nayar A, Ferguson K, Tommasi R, Miller A. Toward the Rational Design of Carbapenem Uptake in Pseudomonas aeruginosa. ACTA ACUST UNITED AC 2015; 22:535-547. [DOI: 10.1016/j.chembiol.2015.03.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 03/14/2015] [Accepted: 03/27/2015] [Indexed: 12/22/2022]
|
17
|
Samanta S, Scorciapino MA, Ceccarelli M. Molecular basis of substrate translocation through the outer membrane channel OprD of Pseudomonas aeruginosa. Phys Chem Chem Phys 2015; 17:23867-76. [DOI: 10.1039/c5cp02844b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The dynamics and interplay of internal and external loops create two alternative paths for the permeation of substrates through the specific outer membrane channel OprD.
Collapse
Affiliation(s)
- Susruta Samanta
- Department of Physics
- University of Cagliari
- I-09042 Monserrato
- Italy
| | | | | |
Collapse
|
18
|
Maffeo C, Bhattacharya S, Yoo J, Wells D, Aksimentiev A. Modeling and simulation of ion channels. Chem Rev 2012; 112:6250-84. [PMID: 23035940 PMCID: PMC3633640 DOI: 10.1021/cr3002609] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Christopher Maffeo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Swati Bhattacharya
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Jejoong Yoo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - David Wells
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| |
Collapse
|
19
|
Wang Y, Zhao X, Sun B, Yu H, Huang X. Molecular dynamics simulation study of the vanillate transport channel of Opdk. Arch Biochem Biophys 2012; 524:132-9. [DOI: 10.1016/j.abb.2012.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 05/07/2012] [Accepted: 05/11/2012] [Indexed: 12/11/2022]
|
20
|
Liu J, Wolfe AJ, Eren E, Vijayaraghavan J, Indic M, van den Berg B, Movileanu L. Cation selectivity is a conserved feature in the OccD subfamily of Pseudomonas aeruginosa. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2908-16. [PMID: 22824298 DOI: 10.1016/j.bbamem.2012.07.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 01/03/2023]
Abstract
To achieve the uptake of small, water-soluble nutrients, Pseudomonas aeruginosa, a pathogenic Gram-negative bacterium, employs substrate-specific channels located within its outer membrane. In this paper, we present a detailed description of the single-channel characteristics of six members of the outer membrane carboxylate channel D (OccD) subfamily. Recent structural studies showed that the OccD proteins share common features, such as a closely related, monomeric, 18-stranded β-barrel conformation and large extracellular loops, which are folded back into the channel lumen. Here, we report that the OccD proteins displayed single-channel activity with a unitary conductance covering an unusually broad range, between 20 and 670pS, as well as a diverse gating dynamics. Interestingly, we found that cation selectivity is a conserved trait among all members of the OccD subfamily, bringing a new distinction between the members of the OccD subfamily and the anion-selective OccK channels. Conserved cation selectivity of the OccD channels is in accord with an increased specificity and selectivity of these proteins for positively charged, carboxylate-containing substrates.
Collapse
Affiliation(s)
- Jiaming Liu
- Department of Physics, Syracuse University, Syracuse, NY 13244-1130, USA
| | | | | | | | | | | | | |
Collapse
|
21
|
Liu J, Eren E, Vijayaraghavan J, Cheneke BR, Indic M, van den Berg B, Movileanu L. OccK channels from Pseudomonas aeruginosa exhibit diverse single-channel electrical signatures but conserved anion selectivity. Biochemistry 2012; 51:2319-30. [PMID: 22369314 DOI: 10.1021/bi300066w] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Pseudomonas aeruginosa is a Gram-negative bacterium that utilizes substrate-specific outer membrane (OM) proteins for the uptake of small, water-soluble nutrients employed in the growth and function of the cell. In this paper, we present for the first time a comprehensive single-channel examination of seven members of the OM carboxylate channel K (OccK) subfamily. Recent biochemical, functional, and structural characterization of the OccK proteins revealed their common features, such as a closely related, monomeric, 18-stranded β-barrel conformation with a kidney-shaped transmembrane pore and the presence of a basic ladder within the channel lumen. Here, we report that the OccK proteins exhibited fairly distinct unitary conductance values, in a much broader range than previously expected, which includes low (~40-100 pS) and medium (~100-380 pS) conductance. These proteins showed diverse single-channel dynamics of current gating transitions, revealing one-open substate (OccK3), two-open substate (OccK4-OccK6), and three-open substate (OccK1, OccK2, and OccK7) kinetics with functionally distinct conformations. Interestingly, we discovered that anion selectivity is a conserved trait among the members of the OccK subfamily, confirming the presence of a net pool of positively charged residues within their central constriction. Moreover, these results are in accord with an increased specificity and selectivity of these protein channels for negatively charged, carboxylate-containing substrates. Our findings might ignite future functional examinations and full atomistic computational studies for unraveling a mechanistic understanding of the passage of small molecules across the lumen of substrate-specific, β-barrel OM proteins.
Collapse
Affiliation(s)
- Jiaming Liu
- Department of Physics, Syracuse University, Syracuse, New York 13244-1130, United States
| | | | | | | | | | | | | |
Collapse
|
22
|
Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, van den Berg B. Substrate specificity within a family of outer membrane carboxylate channels. PLoS Biol 2012; 10:e1001242. [PMID: 22272184 PMCID: PMC3260308 DOI: 10.1371/journal.pbio.1001242] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 11/30/2011] [Indexed: 12/20/2022] Open
Abstract
Characterization of a large family of outer membrane channels from gram-negative bacteria suggest how they can thrive in nutrient-poor environments and how channel inactivation can contribute to antibiotic resistance. Many Gram-negative bacteria, including human pathogens such as Pseudomonas aeruginosa, do not have large-channel porins. This results in an outer membrane (OM) that is highly impermeable to small polar molecules, making the bacteria intrinsically resistant towards many antibiotics. In such microorganisms, the majority of small molecules are taken up by members of the OprD outer membrane protein family. Here we show that OprD channels require a carboxyl group in the substrate for efficient transport, and based on this we have renamed the family Occ, for outer membrane carboxylate channels. We further show that Occ channels can be divided into two subfamilies, based on their very different substrate specificities. Our results rationalize how certain bacteria can efficiently take up a variety of substrates under nutrient-poor conditions without compromising membrane permeability. In addition, they explain how channel inactivation in response to antibiotics can cause resistance but does not lead to decreased fitness. Emerging antibiotic resistance in the treatment of infectious disease is an increasing problem that urgently requires new drug development. In Gram-negative bacteria, the outer membrane (OM) prevents permeation of small molecules, including antibiotics. A family of channel-forming proteins, called OprD proteins, are present in the OM to enable uptake of nutrients required for growth and cellular function. Since these channels also transport antibiotics, understanding how molecules are recognized and transported by these proteins should enable the design of more effective antibiotics. Here, we have characterized by biophysical and biochemical methods the structures and substrate-specificities of nine members of the OprD channel family of a common multidrug-resistant pathogen, Pseudomonas aeruginosa. Because we demonstrate that efficient passage through these channels requires the presence of a carboxyl group in the substrate, we renamed this channel family outer membrane carboxylate channels, or Occ. This broad substrate specificity suggests that such efficient transport allows bacteria to thrive in nutrient-poor environments. We also show markedly varied substrate specificities among the family members, especially for antibiotics, suggesting that mutation of a single channel can result in antibiotic resistance. These results provide the framework for studying the interaction of antibiotics with OM uptake channels, which will facilitate the development of more permeable and thus effective drugs.
Collapse
Affiliation(s)
- Elif Eren
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
| | - Jagamya Vijayaraghavan
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
| | - Jiaming Liu
- Syracuse University, Department of Physics, Syracuse, New York, United States of America
| | - Belete R. Cheneke
- Syracuse University, Department of Physics, Syracuse, New York, United States of America
| | - Debra S. Touw
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
| | - Bryan W. Lepore
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
| | - Mridhu Indic
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
| | - Liviu Movileanu
- Syracuse University, Department of Physics, Syracuse, New York, United States of America
| | - Bert van den Berg
- University of Massachusetts Medical School, Program in Molecular Medicine, Worcester, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
23
|
Fosfomycin enhances the active transport of tobramycin in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2012; 56:1529-38. [PMID: 22232284 DOI: 10.1128/aac.05958-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Elevated levels of mucins present in bronchiectatic airways predispose patients to bacterial infections and reduce the effectiveness of antibiotic therapies by directly inactivating antibiotics. Consequently, new antibiotics that are not inhibited by mucins are needed to treat chronic respiratory infections caused by Pseudomonas aeruginosa and Staphylococcus aureus. In these studies, we demonstrate that fosfomycin synergistically enhances the activity of tobramycin in the presence of mucin. The bactericidal killing of a novel 4:1 (wt/wt) combination of fosfomycin-tobramycin (FTI) is superior (>9 log(10) CFU/ml) relative to its individual components fosfomycin and tobramycin. Additionally, FTI has a mutation frequency resulting in an antibiotic resistance >3 log(10) lower than for fosfomycin and 4 log(10) lower than for tobramycin for P. aeruginosa. Mechanistic studies revealed that chemical adducts are not formed, suggesting that the beneficial effects of the combination are not due to molecular modification of the components. FTI displayed time-kill kinetics similar to tobramycin and killed in a concentration-dependent fashion. The bactericidal effect resulted from inhibition of protein biosynthesis rather than cell wall biosynthesis. Studies using radiolabeled antibiotics demonstrated that tobramycin uptake was energy dependent and that fosfomycin enhanced the uptake of tobramycin in P. aeruginosa in a dose-dependent manner. Lastly, mutants resistant to fosfomycin and tobramycin were auxotrophic for specific carbohydrates and amino acids, suggesting that the resistance arises from mutations in specific active transport mechanisms. Overall, these data demonstrate that fosfomycin enhances the uptake of tobramycin, resulting in increased inhibition of protein synthesis and ultimately bacterial killing.
Collapse
|
24
|
Papp-Wallace KM, Endimiani A, Taracila MA, Bonomo RA. Carbapenems: past, present, and future. Antimicrob Agents Chemother 2011; 55:4943-60. [PMID: 21859938 PMCID: PMC3195018 DOI: 10.1128/aac.00296-11] [Citation(s) in RCA: 860] [Impact Index Per Article: 66.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In this review, we summarize the current "state of the art" of carbapenem antibiotics and their role in our antimicrobial armamentarium. Among the β-lactams currently available, carbapenems are unique because they are relatively resistant to hydrolysis by most β-lactamases, in some cases act as "slow substrates" or inhibitors of β-lactamases, and still target penicillin binding proteins. This "value-added feature" of inhibiting β-lactamases serves as a major rationale for expansion of this class of β-lactams. We describe the initial discovery and development of the carbapenem family of β-lactams. Of the early carbapenems evaluated, thienamycin demonstrated the greatest antimicrobial activity and became the parent compound for all subsequent carbapenems. To date, more than 80 compounds with mostly improved antimicrobial properties, compared to those of thienamycin, are described in the literature. We also highlight important features of the carbapenems that are presently in clinical use: imipenem-cilastatin, meropenem, ertapenem, doripenem, panipenem-betamipron, and biapenem. In closing, we emphasize some major challenges and urge the medicinal chemist to continue development of these versatile and potent compounds, as they have served us well for more than 3 decades.
Collapse
Affiliation(s)
- Krisztina M. Papp-Wallace
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106
- Departments of Medicine
| | - Andrea Endimiani
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106
- Institute for Infectious Diseases, University of Bern 3010, Bern, Switzerland
- Departments of Medicine
| | | | - Robert A. Bonomo
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106
- Departments of Medicine
- Pharmacology
- Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio 44106
| |
Collapse
|
25
|
Cheneke BR, van den Berg B, Movileanu L. Analysis of gating transitions among the three major open states of the OpdK channel. Biochemistry 2011; 50:4987-97. [PMID: 21548584 PMCID: PMC3107985 DOI: 10.1021/bi200454j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OpdK is an outer membrane protein of the pathogenic bacterium Pseudomonas aeruginosa. The recent crystal structure of this protein revealed a monomeric, 18-stranded β-barrel with a kidney-shaped pore, whose constriction features a diameter of 8 Å. Using systematic single-channel electrical recordings of this protein pore reconstituted into planar lipid bilayers under a broad range of ion concentrations, we were able to probe its discrete gating kinetics involving three major and functionally distinct conformations, in which a dominant open substate O(2) is accompanied by less thermodynamically stable substates O(1) and O(3). Single-channel electrical data enabled us to determine the alterations in the energetics and kinetics of the OpdK protein when experimental conditions were changed. In the future, such a semiquantitative analysis might provide a better understanding on the dynamics of current fluctuations of other β-barrel membrane protein channels.
Collapse
Affiliation(s)
- Belete R. Cheneke
- Department of Physics, Syracuse University, 201 Physics Building, Syracuse, New York 13244-1130, USA
| | - Bert van den Berg
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Liviu Movileanu
- Department of Physics, Syracuse University, 201 Physics Building, Syracuse, New York 13244-1130, USA
- Structural Biology, Biochemistry, and Biophysics Program, Syracuse University, 111 College Place, Syracuse, New York 13244-4100, USA
- Syracuse Biomaterials Institute, Syracuse University, 121 Link Hall, Syracuse, New York 13244, USA
| |
Collapse
|
26
|
Moreno R, Martínez-Gomariz M, Yuste L, Gil C, Rojo F. The Pseudomonas putida
Crc global regulator controls the hierarchical assimilation of amino acids in a complete medium: Evidence from proteomic and genomic analyses. Proteomics 2009; 9:2910-28. [DOI: 10.1002/pmic.200800918] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Genetic analysis of genes involved in dipeptide metabolism and cytotoxicity in Pseudomonas aeruginosa PAO1. Microbiology (Reading) 2008; 154:2209-2218. [DOI: 10.1099/mic.0.2007/015032-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
28
|
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
| |
Collapse
|
29
|
Chevalier S, Bodilis J, Jaouen T, Barray S, Feuilloley MGJ, Orange N. Sequence diversity of the OprD protein of environmental Pseudomonas strains. Environ Microbiol 2007; 9:824-35. [PMID: 17298381 DOI: 10.1111/j.1462-2920.2006.01191.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OprD has been widely described for Pseudomonas aeruginosa at both structural and functional levels. Here, we describe the sequence diversity of the OprD proteins from other fluorescent Pseudomonads. We analysed the sequence of the oprD gene in each of the 49 Pseudomonas isolates, mostly putida and fluorescens species, obtained from various environmental sources, including soil, rhizosphere and hospitals. Phylogeny based on OprD sequences distinguished three well-separated clusters in the P. fluorescens species whereas P. putida isolates formed only one cluster. The OprD sequences were generally well conserved within each cluster whereas on the opposite, they were highly variable from one cluster to another and particularly with regards to the cluster of P. aeruginosa. Predicted secondary structures, based on the topological model elaborated for P. aeruginosa, suggest signatures in the large extracellular loops of OprD, which are linked to the OprD-based clusters. Correlations between these OprD-based clusters and ecological niches, growth on various carbon sources and antibiotic sensitivity were investigated.
Collapse
Affiliation(s)
- Sylvie Chevalier
- LMDF (Laboratoire de Microbiologie du Froid), UPRES 2123, Université de Rouen, 55, rue St Germain 27000 Evreux, France.
| | | | | | | | | | | |
Collapse
|
30
|
Tamber S, Maier E, Benz R, Hancock REW. Characterization of OpdH, a Pseudomonas aeruginosa porin involved in the uptake of tricarboxylates. J Bacteriol 2006; 189:929-39. [PMID: 17114261 PMCID: PMC1797325 DOI: 10.1128/jb.01296-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Pseudomonas aeruginosa outer membrane is intrinsically impermeable to many classes of antibiotics, due in part to its relative lack of general uptake pathways. Instead, this organism relies on a large number of substrate-specific uptake porins. Included in this group are the 19 members of the OprD family, which are involved in the uptake of a diverse array of metabolites. One of these porins, OpdH, has been implicated in the uptake of cis-aconitate. Here we demonstrate that this porin may also enable P. aeruginosa to take up other tricarboxylates. Isocitrate and citrate strongly and specifically induced the opdH gene via a mechanism involving derepression by the putative two-component regulatory system PA0756-PA0757. Planar bilayer analysis of purified OpdH demonstrated that it was a channel-forming protein with a large single-channel conductance (230 pS in 1 M KCl; 10-fold higher than that of OprD); however, we were unable to demonstrate the presence of a tricarboxylate binding site within the channel. Thus, these data suggest that the requirement for OpdH for efficient growth on tricarboxylates was likely due to the specific expression of this large-channel porin under particular growth conditions.
Collapse
Affiliation(s)
- Sandeep Tamber
- Department of Microbiology and Immunology, University of British Columbia, #235 2259 Lower Mall, Lower Mall Research Station, Vancouver, British Columbia, V6T 1Z4 Canada
| | | | | | | |
Collapse
|