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Kristensen R, Andersen JB, Rybtke M, Jansen CU, Fritz BG, Kiilerich RO, Uhd J, Bjarnsholt T, Qvortrup K, Tolker-Nielsen T, Givskov M, Jakobsen TH. Inhibition of Pseudomonas aeruginosa quorum sensing by chemical induction of the MexEF-oprN efflux pump. Antimicrob Agents Chemother 2024; 68:e0138723. [PMID: 38189278 PMCID: PMC10848761 DOI: 10.1128/aac.01387-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 11/17/2023] [Indexed: 01/09/2024] Open
Abstract
The cell-to-cell communication system quorum sensing (QS), used by various pathogenic bacteria to synchronize gene expression and increase host invasion potentials, is studied as a potential target for persistent infection control. To search for novel molecules targeting the QS system in the Gram-negative opportunistic pathogen Pseudomonas aeruginosa, a chemical library consisting of 3,280 small compounds from LifeArc was screened. A series of 10 conjugated phenones that have not previously been reported to target bacteria were identified as inhibitors of QS in P. aeruginosa. Two lead compounds (ethylthio enynone and propylthio enynone) were re-synthesized for verification of activity and further elucidation of the mode of action. The isomeric pure Z-ethylthio enynone was used for RNA sequencing, revealing a strong inhibitor of QS-regulated genes, and the QS-regulated virulence factors rhamnolipid and pyocyanin were significantly decreased by treatment with the compounds. A transposon mutagenesis screen performed in a newly constructed lasB-gfp monitor strain identified the target of Z-ethylthio enynone in P. aeruginosa to be the MexEF-OprN efflux pump, which was further established using defined mex knockout mutants. Our data indicate that the QS inhibitory capabilities of Z-ethylthio enynone were caused by the drainage of intracellular signal molecules as a response to chemical-induced stimulation of the MexEF-oprN efflux pump, thereby inhibiting the autogenerated positive feedback and its enhanced signal-molecule synthesis.
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Affiliation(s)
- Rasmus Kristensen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | | | - Blaine Gabriel Fritz
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Rikke Overgaard Kiilerich
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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2
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Blanco-Romero E, Garrido-Sanz D, Durán D, Rybtke M, Tolker-Nielsen T, Redondo-Nieto M, Rivilla R, Martín M. Role of extracellular matrix components in biofilm formation and adaptation of Pseudomonas ogarae F113 to the rhizosphere environment. Front Microbiol 2024; 15:1341728. [PMID: 38333580 PMCID: PMC10850567 DOI: 10.3389/fmicb.2024.1341728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024] Open
Abstract
Regulating the transition of bacteria from motile to sessile lifestyles is crucial for their ability to compete effectively in the rhizosphere environment. Pseudomonas are known to rely on extracellular matrix (ECM) components for microcolony and biofilm formation, allowing them to adapt to a sessile lifestyle. Pseudomonas ogarae F113 possesses eight gene clusters responsible for the production of ECM components. These gene clusters are tightly regulated by AmrZ, a major transcriptional regulator that influences the cellular levels of c-di-GMP. The AmrZ-mediated transcriptional regulation of ECM components is primarily mediated by the signaling molecule c-di-GMP and the flagella master regulator FleQ. To investigate the functional role of these ECM components in P. ogarae F113, we performed phenotypic analyses using mutants in genes encoding these ECM components. These analyses included assessments of colony morphology, dye-staining, static attachment to abiotic surfaces, dynamic biofilm formation on abiotic surfaces, swimming motility, and competitive colonization assays of the rhizosphere. Our results revealed that alginate and PNAG polysaccharides, along with PsmE and the fimbrial low molecular weight protein/tight adherence (Flp/Tad) pilus, are the major ECM components contributing to biofilm formation. Additionally, we found that the majority of these components and MapA are needed for a competitive colonization of the rhizosphere in P. ogarae F113.
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Affiliation(s)
- Esther Blanco-Romero
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Daniel Garrido-Sanz
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - David Durán
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael Rivilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Martín
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
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3
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Abstract
Biofilms have conventionally been perceived as dense bacterial masses on surfaces, following the five-step model of development. Initial biofilm research focused on surface-attached formations, but detached aggregates have received increasing attention in the past decade due to their pivotal role in chronic infections. Understanding their nature sparked fervent discussions in biofilm conferences and scientific literature. This review consolidates current insights on non-attached aggregates, offering examples of their occurrence in nature and diseases. We discuss their formation and dispersion mechanisms, resilience to antibiotics and immune-responses, drawing parallels to surface-attached biofilms. Moreover, we outline available in vitro models for studying non-attached aggregates.
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Affiliation(s)
- Kasper N Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
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4
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Manner C, Dias Teixeira R, Saha D, Kaczmarczyk A, Zemp R, Wyss F, Jaeger T, Laventie BJ, Boyer S, Malone JG, Qvortrup K, Andersen JB, Givskov M, Tolker-Nielsen T, Hiller S, Drescher K, Jenal U. A genetic switch controls Pseudomonas aeruginosa surface colonization. Nat Microbiol 2023; 8:1520-1533. [PMID: 37291227 DOI: 10.1038/s41564-023-01403-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 05/05/2023] [Indexed: 06/10/2023]
Abstract
Efficient colonization of mucosal surfaces is essential for opportunistic pathogens like Pseudomonas aeruginosa, but how bacteria collectively and individually adapt to optimize adherence, virulence and dispersal is largely unclear. Here we identified a stochastic genetic switch, hecR-hecE, which is expressed bimodally and generates functionally distinct bacterial subpopulations to balance P. aeruginosa growth and dispersal on surfaces. HecE inhibits the phosphodiesterase BifA and stimulates the diguanylate cyclase WspR to increase c-di-GMP second messenger levels and promote surface colonization in a subpopulation of cells; low-level HecE-expressing cells disperse. The fraction of HecE+ cells is tuned by different stress factors and determines the balance between biofilm formation and long-range cell dispersal of surface-grown communities. We also demonstrate that the HecE pathway represents a druggable target to effectively counter P. aeruginosa surface colonization. Exposing such binary states opens up new ways to control mucosal infections by a major human pathogen.
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Affiliation(s)
| | | | - Dibya Saha
- Biozentrum, University of Basel, Basel, Switzerland
| | | | | | - Fabian Wyss
- Biozentrum, University of Basel, Basel, Switzerland
| | - Tina Jaeger
- Biozentrum, University of Basel, Basel, Switzerland
- Department Biomedizin, University of Basel, Basel, Switzerland
| | | | - Sebastien Boyer
- sciCORE, Centre for Scientific Computing, University of Basel, Basel, Switzerland
| | - Jacob G Malone
- Biozentrum, University of Basel, Basel, Switzerland
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Jens Bo Andersen
- Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Urs Jenal
- Biozentrum, University of Basel, Basel, Switzerland.
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5
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Gür M, Erdmann J, Will A, Liang Z, Andersen JB, Tolker-Nielsen T, Häussler S. Challenges in using transcriptome data to study the c-di-GMP signaling network in Pseudomonas aeruginosa clinical isolates. FEMS Microbes 2023; 4:xtad012. [PMID: 37564278 PMCID: PMC10411656 DOI: 10.1093/femsmc/xtad012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/31/2023] [Accepted: 07/17/2023] [Indexed: 08/12/2023] Open
Abstract
In the Pseudomonas aeruginosa type strain PA14, 40 genes are known to encode for diguanylate cyclases (DGCs) and/or phosphodiesterases (PDEs), which modulate the intracellular pool of the nucleotide second messenger c-di-GMP. While in general, high levels of c-di-GMP drive the switch from highly motile phenotypes towards a sessile lifestyle, the different c-di-GMP modulating enzymes are responsible for smaller and in parts nonoverlapping phenotypes. In this study, we sought to utilize previously recorded P. aeruginosa gene expression datasets on 414 clinical isolates to uncover transcriptional changes as a result of a high expression of genes encoding DGCs. This approach might provide a unique opportunity to bypass the problem that for many c-di-GMP modulating enzymes it is not known under which conditions their expression is activated. However, while we demonstrate that the selection of subgroups of clinical isolates with high versus low expression of sigma factor encoding genes served the identification of their downstream regulons, we were unable to confirm the predicted DGC regulons, because the high c-di-GMP associated phenotypes were rapidly lost in the clinical isolates,. Further studies are needed to determine the specific mechanisms underlying the loss of cyclase activity upon prolonged cultivation of clinical P. aeruginosa isolates.
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Affiliation(s)
- Melisa Gür
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, Feodor-Lynen-Strasse 7, 30265 Hannover, Germany
| | - Jelena Erdmann
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, Feodor-Lynen-Strasse 7, 30265 Hannover, Germany
| | - Anke Will
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, Feodor-Lynen-Strasse 7, 30265 Hannover, Germany
| | - Ziwei Liang
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B 24.1, 2100 Copenhagen, Denmark
| | - Jens Bo Andersen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B 24.1, 2100 Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B 24.1, 2100 Copenhagen, Denmark
| | - Susanne Häussler
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, Feodor-Lynen-Strasse 7, 30265 Hannover, Germany
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
- Department of Clinical Microbiology, Copenhagen University Hospital – Rigshospitalet, Ole Maaloes Vej 26, 2100 Copenhagen, Denmark
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6
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Liang Z, Nilsson M, Kragh KN, Hedal I, Alcàcer-Almansa J, Kiilerich RO, Andersen JB, Tolker-Nielsen T. The role of individual exopolysaccharides in antibiotic tolerance of Pseudomonas aeruginosa aggregates. Front Microbiol 2023; 14:1187708. [PMID: 37333638 PMCID: PMC10272609 DOI: 10.3389/fmicb.2023.1187708] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/17/2023] [Indexed: 06/20/2023] Open
Abstract
The bacterium Pseudomonas aeruginosa is involved in chronic infections of cystic fibrosis lungs and chronic wounds. In these infections the bacteria are present as aggregates suspended in host secretions. During the course of the infections there is a selection for mutants that overproduce exopolysaccharides, suggesting that the exopolysaccharides play a role in the persistence and antibiotic tolerance of the aggregated bacteria. Here, we investigated the role of individual P. aeruginosa exopolysaccharides in aggregate-associated antibiotic tolerance. We employed an aggregate-based antibiotic tolerance assay on a set of P. aeruginosa strains that were genetically engineered to over-produce a single, none, or all of the three exopolysaccharides Pel, Psl, and alginate. The antibiotic tolerance assays were conducted with the clinically relevant antibiotics tobramycin, ciprofloxacin and meropenem. Our study suggests that alginate plays a role in the tolerance of P. aeruginosa aggregates toward tobramycin and meropenem, but not ciprofloxacin. However, contrary to previous studies we did not observe a role for Psl or Pel in the tolerance of P. aeruginosa aggregates toward tobramycin, ciprofloxacin, and meropenem.
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Affiliation(s)
- Ziwei Liang
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Ida Hedal
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Júlia Alcàcer-Almansa
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Bacterial Infections: Antimicrobial Therapies Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Rikke Overgaard Kiilerich
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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7
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Beilharz K, Kragh KN, Fritz B, Kirkegaard JB, Tolker-Nielsen T, Bjarnsholt T, Lichtenberg M. Protocol to assess metabolic activity of Pseudomonas aeruginosa by measuring heat flow using isothermal calorimetry. STAR Protoc 2023; 4:102269. [PMID: 37133990 PMCID: PMC10176065 DOI: 10.1016/j.xpro.2023.102269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/16/2023] [Accepted: 04/04/2023] [Indexed: 05/04/2023] Open
Abstract
Here, we present a protocol for assessing metabolic activity of bacterial populations by measuring heat flow using isothermal calorimetry. We outline the steps for preparing the different growth models of Pseudomonas aeruginosa and performing continuous metabolic activity measurements in the calScreener. We detail simple principal component analysis to differentiate between metabolic states of different populations and probabilistic logistic classification to assess resemblance to wild-type bacteria. This protocol for fine-scale metabolic measurement can aid in understanding microbial physiology. For complete details on the use and execution of this protocol, please refer to Lichtenberg et al. (2022).1.
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Affiliation(s)
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Blaine Fritz
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
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8
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Armengol E, Kragh KN, Tolker-Nielsen T, Sierra JM, Higazy D, Ciofu O, Viñas M, Høiby N. Colistin Enhances Rifampicin's Antimicrobial Action in Colistin-Resistant Pseudomonas aeruginosa Biofilms. Antimicrob Agents Chemother 2023; 67:e0164122. [PMID: 36856424 PMCID: PMC10112245 DOI: 10.1128/aac.01641-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/30/2023] [Indexed: 03/02/2023] Open
Abstract
The emergence of multidrug-resistant Pseudomonas aeruginosa infections has urged the need to find new strategies, such as the use of combinations of antibiotics. Among these, the combination of colistin with other antibiotics has been studied. Here, the action of combinations of colistin and rifampicin on both planktonic and sessile cells of colistin-resistant P. aeruginosa was studied. Dynamic biofilms were formed and treated with such a combination, resulting in an active killing effect of both colistin-resistant and colistin-susceptible P. aeruginosa in biofilms. The results suggest that the action of colistin on the outer membrane facilitates rifampicin penetration, regardless of the colistin-resistant phenotype. Based on these in vitro data, we propose a colistin-rifampicin combination as a promising treatment for infections caused by colistin-resistant P. aeruginosa.
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Affiliation(s)
- Eva Armengol
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Laboratory of Molecular Microbiology & Antimicrobials, Department of Pathology & Experimental Therapeutics, Medical School and IDIBELL, University of Barcelona, Hospitalet de Llobregat, Spain
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Josep M. Sierra
- Laboratory of Molecular Microbiology & Antimicrobials, Department of Pathology & Experimental Therapeutics, Medical School and IDIBELL, University of Barcelona, Hospitalet de Llobregat, Spain
| | - Doaa Higazy
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Oana Ciofu
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Miguel Viñas
- Laboratory of Molecular Microbiology & Antimicrobials, Department of Pathology & Experimental Therapeutics, Medical School and IDIBELL, University of Barcelona, Hospitalet de Llobregat, Spain
| | - Niels Høiby
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
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9
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Bellich B, Terán LC, Fazli MM, Berti F, Rizzo R, Tolker-Nielsen T, Cescutti P. The Bep gene cluster in Burkholderia cenocepacia H111 codes for a water-insoluble exopolysaccharide essential for biofilm formation. Carbohydr Polym 2023; 301:120318. [PMID: 36436859 PMCID: PMC9713610 DOI: 10.1016/j.carbpol.2022.120318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/22/2022] [Accepted: 11/05/2022] [Indexed: 11/13/2022]
Abstract
Burkholderia cenocepacia is an opportunistic pathogen isolated from cystic fibrosis patients where it causes infections that are extremely difficult to treat with antibiotics, and sometimes have a fatal outcome. Biofilm is a virulence trait of B. cenocepacia, and is associated with infection persistence and increased tolerance to antibiotics. In biofilms exopolysaccharides have an important role, conferring mechanical stability and antibiotic tolerance. Two different exopolysaccharides were isolated from B. cenocepacia H111 biofilms: a water-soluble polysaccharide rich in rhamnose and containing an L-Man residue, and a water-insoluble polymer made of glucose, galactose and mannose. In the present work, the product encoded by B. cenocepacia H111 bepA-L gene cluster was identified as the water-insoluble exopolysaccharide, using mutant strains and NMR spectroscopy of the purified polysaccharides. It was also demonstrated that the B. cenocepacia H111 wild type strain produces the water-insoluble exopolysaccharide in pellicles, thus underlining its potential importance in in vivo infections.
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Affiliation(s)
- Barbara Bellich
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Bdg. C11, 34127 Trieste, Italy
| | - Lucrecia C Terán
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Bdg. C11, 34127 Trieste, Italy
| | - Magnus M Fazli
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | | | - Roberto Rizzo
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Bdg. C11, 34127 Trieste, Italy
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Paola Cescutti
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Bdg. C11, 34127 Trieste, Italy.
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10
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Lichtenberg M, Kragh KN, Fritz B, Kirkegaard JB, Tolker-Nielsen T, Bjarnsholt T. Cyclic-di-GMP signaling controls metabolic activity in Pseudomonas aeruginosa. Cell Rep 2022; 41:111515. [DOI: 10.1016/j.celrep.2022.111515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 07/13/2022] [Accepted: 09/26/2022] [Indexed: 11/03/2022] Open
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11
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Liang Z, Rybtke M, Kragh KN, Johnson O, Schicketanz M, Zhang YE, Andersen JB, Tolker-Nielsen T. Transcription of the Alginate Operon in Pseudomonas aeruginosa Is Regulated by c-di-GMP. Microbiol Spectr 2022; 10:e0067522. [PMID: 35862969 PMCID: PMC9431422 DOI: 10.1128/spectrum.00675-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/19/2022] [Indexed: 02/03/2023] Open
Abstract
Overproduction of the exopolysaccharide alginate contributes to the pathogenicity and antibiotic tolerance of Pseudomonas aeruginosa in chronic infections. The second messenger, c-di-GMP, is a positive regulator of the production of various biofilm matrix components and is known to regulate alginate synthesis at the posttranslational level in P. aeruginosa. We provide evidence that c-di-GMP also regulates transcription of the alginate operon in P. aeruginosa. Previous work has shown that transcription of the alginate operon is regulated by nine different proteins, AmrZ, AlgP, IHFα, IHFβ, CysB, Vfr, AlgR, AlgB, and AlgQ, and we investigated if some of these proteins function as a c-di-GMP effector. We found that deletion of algP, algQ, IHFα, and IHFβ had only a marginal effect on the transcription of the alginate operon. Deletion of vfr and cysB led to decreased transcription of the alginate operon, and the dependence of the c-di-GMP level was less pronounced, indicating that Vfr and CysB could be partially required for c-di-GMP-mediated regulation of alginate operon transcription. Our experiments indicated that the AmrZ, AlgR, and AlgB proteins are absolutely required for transcription of the alginate operon. However, differential radial capillary action of ligand assay (DRaCALA) and site-directed mutagenesis indicated that c-di-GMP does not bind to any of the AmrZ, AlgR, and AlgB proteins. IMPORTANCE The proliferation of alginate-overproducing P. aeruginosa variants in the lungs of cystic fibrosis patients often leads to chronic infection. The alginate functions as a biofilm matrix that protects the bacteria against host immune defenses and antibiotic treatment. Knowledge about the regulation of alginate synthesis is important in order to identify drug targets for the development of medicine against chronic P. aeruginosa infections. We provide evidence that c-di-GMP positively regulates transcription of the alginate operon in P. aeruginosa. Moreover, we revisited the role of the known alginate regulators, AmrZ, AlgP, IHFα, IHFβ, CysB, Vfr, AlgR, AlgB, and AlgQ, and found that their effect on transcription of the alginate operon is highly varied. Deletion of algP, algQ, IHFα, or IHFβ only had a marginal effect on transcription of the alginate operon, whereas deletion of vfr or cysB led to decreased transcription and deletion of amrZ, algR, or algB abrogated transcription.
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Affiliation(s)
- Ziwei Liang
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Owen Johnson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Muriel Schicketanz
- Department of Biology, Copenhagen Biocenter, University of Copenhagen, Copenhagen, Denmark
| | - Yong Everett Zhang
- Department of Biology, Copenhagen Biocenter, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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12
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Wu H, Song L, Yam JKH, Plotkin M, Wang H, Rybtke M, Seliktar D, Kofidis T, Høiby N, Tolker-Nielsen T, Song Z, Givskov M. Effects of antibiotic treatment and phagocyte infiltration on development of Pseudomonas aeruginosa biofilm—Insights from the application of a novel PF hydrogel model in vitro and in vivo. Front Cell Infect Microbiol 2022; 12:826450. [PMID: 35959369 PMCID: PMC9362844 DOI: 10.3389/fcimb.2022.826450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background and purpose Bacterial biofilm infections are major health issues as the infections are highly tolerant to antibiotics and host immune defenses. Appropriate biofilm models are important to develop and improve to make progress in future biofilm research. Here, we investigated the ability of PF hydrogel material to facilitate the development and study of Pseudomonas aeruginosa biofilms in vitro and in vivo. Methods Wild-type P. aeruginosa PAO1 bacteria were embedded in PF hydrogel situated in vitro or in vivo, and the following aspects were investigated: 1) biofilm development; 2) host immune response and its effect on the bacteria; and 3) efficacy of antibiotic treatment. Results Microscopy demonstrated that P. aeruginosa developed typical biofilms inside the PF hydrogels in vitro and in mouse peritoneal cavities where the PF hydrogels were infiltrated excessively by polymorphonuclear leukocytes (PMNs). The bacteria remained at a level of ~106 colony-forming unit (CFU)/hydrogel for 7 days, indicating that the PMNs could not eradicate the biofilm bacteria. β-Lactam or aminoglycoside mono treatment at 64× minimal inhibitory concentration (MIC) killed all bacteria in day 0 in vitro biofilms, but not in day 1 and older biofilms, even at a concentration of 256× MIC. Combination treatment with the antibiotics at 256× MIC completely killed the bacteria in day 1 in vitro biofilms, and combination treatment in most of the cases showed significantly better bactericidal effects than monotherapies. However, in the case of the established in vivo biofilms, the mono and combination antibiotic treatments did not efficiently kill the bacteria. Conclusion Our results indicate that the bacteria formed typical biofilms in PF hydrogel in vitro and in vivo and that the biofilm bacteria were tolerant against antibiotics and host immunity. The PF hydrogel biofilm model is simple and easy to fabricate and highly reproducible with various application possibilities. We conclude that the PF hydrogel biofilm model is a new platform that will facilitate progress in future biofilm investigations, as well as studies of the efficacy of new potential medicine against biofilm infections.
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Affiliation(s)
- Hong Wu
- Costerton Biofilm Center, and Institute of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Lulu Song
- The Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technical University, Singapore, Singapore
| | - Joey Kuok Hoong Yam
- The Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technical University, Singapore, Singapore
| | - Marian Plotkin
- Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore, Singapore
| | - Hengzhuang Wang
- Department of Clinical Microbiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center, and Institute of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dror Seliktar
- Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore, Singapore
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Theodoros Kofidis
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Cardiac, Thoracic and Vascular Surgery, National University Heart Centre, National University Health System, Singapore, Singapore
| | - Niels Høiby
- Costerton Biofilm Center, and Institute of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, and Institute of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zhijun Song
- Department of Clinical Microbiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Hospital South West Jutland, University Hospital of Southern Denmark, Esbjerg, Denmark
- *Correspondence: Zhijun Song,
| | - Michael Givskov
- Costerton Biofilm Center, and Institute of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- The Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technical University, Singapore, Singapore
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13
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Lichtenberg M, Line L, Schrameyer V, Jakobsen TH, Rybtke ML, Toyofuku M, Nomura N, Kolpen M, Tolker-Nielsen T, Kühl M, Bjarnsholt T, Jensen PØ. Nitric-oxide-driven oxygen release in anoxic Pseudomonas aeruginosa. iScience 2021; 24:103404. [PMID: 34849468 PMCID: PMC8608891 DOI: 10.1016/j.isci.2021.103404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 11/19/2022] Open
Abstract
Denitrification supports anoxic growth of Pseudomonas aeruginosa in infections. Moreover, denitrification may provide oxygen (O2) resulting from dismutation of the denitrification intermediate nitric oxide (NO) as seen in Methylomirabilis oxyfera. To examine the prevalence of NO dismutation we studied O2 release by P. aeruginosa in airtight vials. P. aeruginosa rapidly depleted O2 but NO supplementation generated peaks of O2 at the onset of anoxia, and we demonstrate a direct role of NO in the O2 release. However, we were not able to detect genetic evidence for putative NO dismutases. The supply of endogenous O2 at the onset of anoxia could play an adaptive role when P. aeruginosa enters anaerobiosis. Furthermore, O2 generation by NO dismutation may be more widespread than indicated by the reports on the distribution of homologues genes. In general, NO dismutation may allow removal of nitrate by denitrification without release of the very potent greenhouse gas, nitrous oxide. Pseudomonas aeruginosa was found to release O2 at the onset of anoxia Peaks of O2 were amplified in a nitric oxide reductase (NOR) mutant The O2 release was mediated by nitric oxide (NO)
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Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Laura Line
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Verena Schrameyer
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000 Helsingør, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Morten Levin Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Masanori Toyofuku
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, 305-8577 Tsukuba, Japan
| | - Nobuhiko Nomura
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, 305-8577 Tsukuba, Japan
| | - Mette Kolpen
- Department of Clinical Microbiology, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000 Helsingør, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, 2100 Copenhagen, Denmark
- Center for Rheumatology and Spine Diseases, Institute for Inflammation Research, Rigshospitalet, 2100 Copenhagen, Denmark
- Corresponding author
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14
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Flagstad T, Pedersen MT, Jakobsen TH, Felding J, Tolker-Nielsen T, Givskov M, Qvortrup K, Nielsen TE. Solid-phase synthesis and biological evaluation of piperazine-based novel bacterial topoisomerase inhibitors. Bioorg Med Chem Lett 2021; 57:128499. [PMID: 34906671 DOI: 10.1016/j.bmcl.2021.128499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 11/28/2022]
Abstract
There is an emerging global need for new and more effective antibiotics against multi-resistant bacteria. This situation has led to massive industrial investigations on novel bacterial topoisomerase inhibitors (NBTIs) that target the vital bacterial enzymes DNA gyrase and topoisomerase IV. However, several of the NBTI compound classes have been associated with inhibition of the hERG potassium channel, an undesired cause of cardiac arrhythmia, which challenges medicinal chemistry efforts through lengthy synthetic routes. We herein present a solid-phase strategy that rapidly facilitates the chemical synthesis of a promising new class of NBTIs. A proof-of-concept library was synthesized with the ability to modulate both hERG affinity and antibacterial activity through scaffold substitutions.
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Affiliation(s)
- Thomas Flagstad
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Mette T Pedersen
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Tim H Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | | | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Thomas E Nielsen
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark; Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore.
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15
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Jansen CU, Uhd J, Andersen JB, Hultqvist LD, Jakobsen TH, Nilsson M, Nielsen TE, Givskov M, Tolker-Nielsen T, Qvortrup KM. SAR study of 4-arylazo-3,5-diamino-1 H-pyrazoles: identification of small molecules that induce dispersal of Pseudomonas aeruginosa biofilms. RSC Med Chem 2021; 12:1868-1878. [PMID: 34841247 DOI: 10.1039/d1md00275a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 08/30/2021] [Indexed: 12/27/2022] Open
Abstract
By screening of a collection of 50 000 small-molecule compounds, we recently identified 4-arylazo-3,5-diamino-1H-pyrazoles as a novel group of anti-biofilm agents. Here, we report a SAR study based on 60 analogues by examining ways in which the pharmacophore can be further optimized, for example, via substitutions in the aryl ring. The SAR study revealed the very potent anti-biofilm compound 4-(2-(2-fluorophenyl)hydrazineylidene)-5-imino-4,5-dihydro-1H-pyrazol-3-amine (2).
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Affiliation(s)
- Charlotte U Jansen
- Department of Chemistry, Technical University of Denmark DK-2800 Lyngby Denmark
| | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark DK-2800 Lyngby Denmark
| | - Jens B Andersen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Louise D Hultqvist
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Tim H Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Thomas E Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University Singapore
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen DK-2200 Copenhagen Denmark
| | - Katrine M Qvortrup
- Department of Chemistry, Technical University of Denmark DK-2800 Lyngby Denmark
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16
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Røder HL, Trivedi U, Russel J, Kragh KN, Herschend J, Thalsø-Madsen I, Tolker-Nielsen T, Bjarnsholt T, Burmølle M, Madsen JS. Biofilms can act as plasmid reserves in the absence of plasmid specific selection. NPJ Biofilms Microbiomes 2021; 7:78. [PMID: 34620879 PMCID: PMC8497521 DOI: 10.1038/s41522-021-00249-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/15/2021] [Indexed: 02/06/2023] Open
Abstract
Plasmids facilitate rapid bacterial adaptation by shuttling a wide variety of beneficial traits across microbial communities. However, under non-selective conditions, maintaining a plasmid can be costly to the host cell. Nonetheless, plasmids are ubiquitous in nature where bacteria adopt their dominant mode of life - biofilms. Here, we demonstrate that biofilms can act as spatiotemporal reserves for plasmids, allowing them to persist even under non-selective conditions. However, under these conditions, spatial stratification of plasmid-carrying cells may promote the dispersal of cells without plasmids, and biofilms may thus act as plasmid sinks.
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Affiliation(s)
- Henriette Lyng Røder
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Urvish Trivedi
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Russel
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Jakob Herschend
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ida Thalsø-Madsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Mette Burmølle
- 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.
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17
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Nair HAS, Subramoni S, Poh WH, Hasnuddin NTB, Tay M, Givskov M, Tolker-Nielsen T, Kjelleberg S, McDougald D, Rice SA. Carbon starvation of Pseudomonas aeruginosa biofilms selects for dispersal insensitive mutants. BMC Microbiol 2021; 21:255. [PMID: 34551714 PMCID: PMC8459498 DOI: 10.1186/s12866-021-02318-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Biofilms disperse in response to specific environmental cues, such as reduced oxygen concentration, changes in nutrient concentration and exposure to nitric oxide. Interestingly, biofilms do not completely disperse under these conditions, which is generally attributed to physiological heterogeneity of the biofilm. However, our results suggest that genetic heterogeneity also plays an important role in the non-dispersing population of P. aeruginosa in biofilms after nutrient starvation. RESULTS In this study, 12.2% of the biofilm failed to disperse after 4 d of continuous starvation-induced dispersal. Cells were recovered from the dispersal phase as well as the remaining biofilm. For 96 h starved biofilms, rugose small colony variants (RSCV) were found to be present in the biofilm, but were not observed in the dispersal effluent. In contrast, wild type and small colony variants (SCV) were found in high numbers in the dispersal phase. Genome sequencing of these variants showed that most had single nucleotide mutations in genes associated with biofilm formation, e.g. in wspF, pilT, fha1 and aguR. Complementation of those mutations restored starvation-induced dispersal from the biofilms. Because c-di-GMP is linked to biofilm formation and dispersal, we introduced a c-di-GMP reporter into the wild-type P. aeruginosa and monitored green fluorescent protein (GFP) expression before and after starvation-induced dispersal. Post dispersal, the microcolonies were smaller and significantly brighter in GFP intensity, suggesting the relative concentration of c-di-GMP per cell within the microcolonies was also increased. Furthermore, only the RSCV showed increased c-di-GMP, while wild type and SCV were no different from the parental strain. CONCLUSIONS This suggests that while starvation can induce dispersal from the biofilm, it also results in strong selection for mutants that overproduce c-di-GMP and that fail to disperse in response to the dispersal cue, starvation.
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Affiliation(s)
- Harikrishnan A S Nair
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore.,Interdisciplinary Graduate School, Singapore, Singapore.,Present address: Eppendorf AG, Barkhausenweg 1, 22339, Hamburg, Germany
| | - Sujatha Subramoni
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore
| | - Wee Han Poh
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore
| | | | - Martin Tay
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore.,Present address: Public Utilities Board, Government of Singapore, Singapore, Singapore
| | - Michael Givskov
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore.,Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Staffan Kjelleberg
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Diane McDougald
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore. .,The Ithree Institute, University of Technology Sydney, Sydney, Australia.
| | - Scott A Rice
- The Singapore Centre for Environmental Life Sciences Engineering, Singapore, Singapore. .,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore. .,The Ithree Institute, University of Technology Sydney, Sydney, Australia.
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18
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Soh EYC, Smith F, Gimenez MR, Yang L, Vejborg RM, Fletcher M, Halliday N, Bleves S, Heeb S, Cámara M, Givskov M, Hardie KR, Tolker-Nielsen T, Ize B, Williams P. Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc1 sub-unit. PLoS Pathog 2021; 17:e1009425. [PMID: 34460871 PMCID: PMC8432897 DOI: 10.1371/journal.ppat.1009425] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 09/10/2021] [Accepted: 08/10/2021] [Indexed: 11/18/2022] Open
Abstract
Extracellular DNA (eDNA) is a major constituent of the extracellular matrix of Pseudomonas aeruginosa biofilms and its release is regulated via pseudomonas quinolone signal (PQS) dependent quorum sensing (QS). By screening a P. aeruginosa transposon library to identify factors required for DNA release, mutants with insertions in the twin-arginine translocation (Tat) pathway were identified as exhibiting reduced eDNA release, and defective biofilm architecture with enhanced susceptibility to tobramycin. P. aeruginosa tat mutants showed substantial reductions in pyocyanin, rhamnolipid and membrane vesicle (MV) production consistent with perturbation of PQS-dependent QS as demonstrated by changes in pqsA expression and 2-alkyl-4-quinolone (AQ) production. Provision of exogenous PQS to the tat mutants did not return pqsA, rhlA or phzA1 expression or pyocyanin production to wild type levels. However, transformation of the tat mutants with the AQ-independent pqs effector pqsE restored phzA1 expression and pyocyanin production. Since mutation or inhibition of Tat prevented PQS-driven auto-induction, we sought to identify the Tat substrate(s) responsible. A pqsA::lux fusion was introduced into each of 34 validated P. aeruginosa Tat substrate deletion mutants. Analysis of each mutant for reduced bioluminescence revealed that the primary signalling defect was associated with the Rieske iron-sulfur subunit of the cytochrome bc1 complex. In common with the parent strain, a Rieske mutant exhibited defective PQS signalling, AQ production, rhlA expression and eDNA release that could be restored by genetic complementation. This defect was also phenocopied by deletion of cytB or cytC1. Thus, either lack of the Rieske sub-unit or mutation of cytochrome bc1 genes results in the perturbation of PQS-dependent autoinduction resulting in eDNA deficient biofilms, reduced antibiotic tolerance and compromised virulence factor production. Pseudomonas aeruginosa is a highly adaptable human pathogen responsible for causing chronic biofilm-associated infections. Biofilms are highly refractory to host defences and antibiotics and thus difficult to eradicate. The biofilm extracellular matrix incorporates extracellular DNA (eDNA). This stabilizes biofilm architecture and helps confer tolerance to antibiotics. Since mechanisms that control eDNA release are not well understood, we screened a P. aeruginosa mutant bank for strains with defects in eDNA release and discovered a role for the twin-arginine translocation (Tat) pathway that exports folded proteins across the cytoplasmic membrane. Perturbation of the Tat pathway resulted in defective biofilms susceptible to antibiotic treatment as a consequence of perturbed pseudomonas quinolone (PQS) signalling. This resulted in the failure to produce or release biofilm components including eDNA, phenazines and rhamnolipids as well as microvesicles. Furthermore, we discovered that perturbation of PQS signalling was a consequence of the inability of tat mutants to translocate the Rieske subunit of the cytochrome bc1 complex involved in electron transfer and energy transduction. Given the importance of PQS signalling and the Tat system to virulence and biofilm maturation in P. aeruginosa, our findings underline the potential of the Tat system as a drug target for novel antimicrobial agents.
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Affiliation(s)
- Eliza Ye-Chen Soh
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Frances Smith
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Maxime Rémi Gimenez
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Rebecca Munk Vejborg
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthew Fletcher
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Nigel Halliday
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Sophie Bleves
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
| | - Stephan Heeb
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miguel Cámara
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kim R. Hardie
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (TT-N); (BI); (PW)
| | - Bérengère Ize
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille University, Marseille, France
- * E-mail: (TT-N); (BI); (PW)
| | - Paul Williams
- Biodiscovery Institute, National Biofilms Innovation Centre and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (TT-N); (BI); (PW)
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19
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Andersen JB, Hultqvist LD, Jansen CU, Jakobsen TH, Nilsson M, Rybtke M, Uhd J, Fritz BG, Seifert R, Berthelsen J, Nielsen TE, Qvortrup K, Givskov M, Tolker-Nielsen T. Identification of small molecules that interfere with c-di-GMP signaling and induce dispersal of Pseudomonas aeruginosa biofilms. NPJ Biofilms Microbiomes 2021; 7:59. [PMID: 34244523 PMCID: PMC8271024 DOI: 10.1038/s41522-021-00225-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/11/2021] [Indexed: 12/29/2022] Open
Abstract
Microbial biofilms are involved in a number of infections that cannot be cured, as microbes in biofilms resist host immune defenses and antibiotic therapies. With no strict biofilm-antibiotic in the current pipelines, there is an unmet need for drug candidates that enable the current antibiotics to eradicate bacteria in biofilms. We used high-throughput screening to identify chemical compounds that reduce the intracellular c-di-GMP content in Pseudomonas aeruginosa. This led to the identification of a small molecule that efficiently depletes P. aeruginosa for c-di-GMP, inhibits biofilm formation, and disperses established biofilm. A combination of our lead compound with standard of care antibiotics showed improved eradication of an implant-associated infection established in mice. Genetic analyses provided evidence that the anti-biofilm compound stimulates the activity of the c-di-GMP phosphodiesterase BifA in P. aeruginosa. Our work constitutes a proof of concept for c-di-GMP phosphodiesterase-activating drugs administered in combination with antibiotics as a viable treatment strategy for otherwise recalcitrant infections.
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Affiliation(s)
- Jens Bo Andersen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise Dahl Hultqvist
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Tim Holm Jakobsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Nilsson
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Blaine Gabriel Fritz
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Roland Seifert
- Institute of Pharmacology and Research Core Unit Metabolomics, Hannover Medical School Carl-Neuberg-Straße 1, Hannover, Germany
| | - Jens Berthelsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Eiland Nielsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Michael Givskov
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center. Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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20
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Moser C, Jensen PØ, Thomsen K, Kolpen M, Rybtke M, Lauland AS, Trøstrup H, Tolker-Nielsen T. Immune Responses to Pseudomonas aeruginosa Biofilm Infections. Front Immunol 2021; 12:625597. [PMID: 33692800 PMCID: PMC7937708 DOI: 10.3389/fimmu.2021.625597] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/20/2021] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa is a key pathogen of chronic infections in the lungs of cystic fibrosis patients and in patients suffering from chronic wounds of diverse etiology. In these infections the bacteria congregate in biofilms and cannot be eradicated by standard antibiotic treatment or host immune responses. The persistent biofilms induce a hyper inflammatory state that results in collateral damage of the adjacent host tissue. The host fails to eradicate the biofilm infection, resulting in hindered remodeling and healing. In the present review we describe our current understanding of innate and adaptive immune responses elicited by P. aeruginosa biofilms in cystic fibrosis lung infections and chronic wounds. This includes the mechanisms that are involved in the activation of the immune responses, as well as the effector functions, the antimicrobial components and the associated tissue destruction. The mechanisms by which the biofilms evade immune responses, and potential treatment targets of the immune response are also discussed.
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Affiliation(s)
- Claus Moser
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kim Thomsen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Mette Kolpen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Sofie Lauland
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Hannah Trøstrup
- Department of Plastic Surgery and Breast Surgery, Zealand University Hospital, Roskilde, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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21
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Bellich B, Jou IA, Buriola C, Ravenscroft N, Brady JW, Fazli M, Tolker-Nielsen T, Rizzo R, Cescutti P. The biofilm of Burkholderia cenocepacia H111 contains an exopolysaccharide composed of l-rhamnose and l-mannose: Structural characterization and molecular modelling. Carbohydr Res 2020; 499:108231. [PMID: 33440288 DOI: 10.1016/j.carres.2020.108231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 10/22/2022]
Abstract
Burkholderia cenocepacia belongs to the Burkholderia Cepacia Complex, a group of 22 closely related species both of clinical and environmental origin, infecting cystic fibrosis patients. B. cenocepacia accounts for the majority of the clinical isolates, comprising the most virulent and transmissible strains. The capacity to form biofilms is among the many virulence determinants of B. cenocepacia, a characteristic that confers enhanced tolerance to some antibiotics, desiccation, oxidizing agents, and host defenses. Exopolysaccharides are a major component of biofilm matrices, particularly providing mechanical stability to biofilms. Recently, a water-insoluble exopolysaccharide produced by B. cenocepacia H111 in biofilm was characterized. In the present study, a water-soluble exopolysaccharide was extracted from B. cenocepacia H111 biofilm, and its structure was determined by GLC-MS, NMR and ESI-MS. The repeating unit is a linear rhamno-tetrasaccharide with 50% replacement of a 3-α-L-Rha with a α-3-L-Man. [2)-α-L-Rhap-(1→3)-α-L-[Rhap or Manp]-(1→3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→]n Molecular modelling was used to obtain information about local structural motifs which could give information about the polysaccharide conformation.
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Affiliation(s)
- Barbara Bellich
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, Bdg. C11, 34127, Trieste, Italy
| | - Ining A Jou
- Department of Food Science, Cornell University, Ithaca, NY, 14853, USA
| | - Claudia Buriola
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, Bdg. C11, 34127, Trieste, Italy
| | - Neil Ravenscroft
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - John W Brady
- Department of Food Science, Cornell University, Ithaca, NY, 14853, USA
| | - Mustafa Fazli
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Roberto Rizzo
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, Bdg. C11, 34127, Trieste, Italy
| | - Paola Cescutti
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, Bdg. C11, 34127, Trieste, Italy.
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22
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Henriksen K, Rørbo N, Rybtke ML, Martinet MG, Tolker-Nielsen T, Høiby N, Middelboe M, Ciofu O. P. aeruginosa flow-cell biofilms are enhanced by repeated phage treatments but can be eradicated by phage-ciprofloxacin combination. Pathog Dis 2020; 77:5368070. [PMID: 30821815 DOI: 10.1093/femspd/ftz011] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/28/2019] [Indexed: 02/06/2023] Open
Abstract
Phage therapy has shown promising results in the treatment of Pseudomonas aeruginosa biofilm infections in animal studies and case reports. The aim of this study was to quantify effects of phage treatments on P. aeruginosa biofilm production and structure. Confocal scanning microscopy was used to follow the interaction between a cocktail of three virulent phages and P. aeruginosa flow-cell biofilms. The role of (i) biofilm age, (ii) repeated phage treatments, (iii) alginate production and (iv) the combination with sub-MIC levels of ciprofloxacin was investigated. Single phage treatment in the early biofilm stages significantly reduced P. aeruginosa PAO1 biovolume (85%-98% reduction). Repeated phage treatments increased the biovolume from 18.25 (untreated biofilm) to 22.24 and 31.07 µm3/µm2 for biofilms treated with phages twice and thrice, respectively. Alginate protected against the phage treatment as the live biovolume remained unaffected by the phage treatment in the mucoid biofilm (20.11 µm3/µm2 in untreated and 21.74 µm3/µm2 in phage-treated biofilm) but decreased in the PAO1 biofilm from 27.35 to 0.89 µm3/µm2. We show that the combination of phages with antibiotics at sub-MIC levels caused a ∼6 log units reduction in the abundance of P. aeruginosa cells in biofilms and that phage treatment increased the size of microcolonies in flow-cell system.
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Affiliation(s)
- Karoline Henriksen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark
| | - Nanna Rørbo
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Morten Levin Rybtke
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark
| | - Mark Grevsen Martinet
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark
| | - Niels Høiby
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark.,Department of Clinical Microbiology, University Hospital, Rigshospitalet, Henrik Harpestrengs Vej 4A, 2100 , Copenhagen, Denmark
| | - Mathias Middelboe
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Oana Ciofu
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 N, Copenhagen, Denmark
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23
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Qvortrup K, Hultqvist LD, Nilsson M, Jakobsen TH, Jansen CU, Uhd J, Andersen JB, Nielsen TE, Givskov M, Tolker-Nielsen T. Small Molecule Anti-biofilm Agents Developed on the Basis of Mechanistic Understanding of Biofilm Formation. Front Chem 2019; 7:742. [PMID: 31737611 PMCID: PMC6838868 DOI: 10.3389/fchem.2019.00742] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/17/2019] [Indexed: 01/12/2023] Open
Abstract
Microbial biofilms are the cause of persistent infections associated with various medical implants and distinct body sites such as the urinary tract, lungs, and wounds. Compared with their free living counterparts, bacteria in biofilms display a highly increased resistance to immune system activities and antibiotic treatment. Therefore, biofilm infections are difficult or impossible to treat with our current armory of antibiotics. The challenges associated with biofilm infections have urged researchers to pursue a better understanding of the molecular mechanisms that are involved in the formation and dispersal of biofilms, and this has led to the identification of several steps that could be targeted in order to eradicate these challenging infections. Here we describe mechanisms that are involved in the regulation of biofilm development in Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii, and provide examples of chemical compounds that have been developed to specifically inhibit these processes. These compounds include (i) pilicides and curlicides which inhibit the initial steps of biofilm formation by E. coli; (ii) compounds that interfere with c-di-GMP signaling in P. aeruginosa and E. coli; and (iii) compounds that inhibit quorum-sensing in P. aeruginosa and A. baumannii. In cases where compound series have a defined molecular target, we focus on elucidating structure activity relationship (SAR) trends within the particular compound series.
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Affiliation(s)
- Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Louise Dahl Hultqvist
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Nilsson
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Jens Bo Andersen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Michael Givskov
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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24
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Nilsson M, Givskov M, Twetman S, Tolker-Nielsen T. Inactivation of the pgmA Gene in Streptococcus mutans Significantly Decreases Biofilm-Associated Antimicrobial Tolerance. Microorganisms 2019; 7:microorganisms7090310. [PMID: 31484288 PMCID: PMC6780209 DOI: 10.3390/microorganisms7090310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022] Open
Abstract
Screening of a Streptococcus mutans mutant library indicated that pgmA mutants displayed a reduced biofilm-associated tolerance toward gentamicin. The biofilms formed by the S. mutanspgmA mutant also displayed decreased tolerance towards linezolid and vancomycin compared to wild-type biofilms. On the contrary, the resistance of planktonic S. mutanspgmA cells to gentamycin, linezolid, and vancomycin was more similar to wild-type levels. Investigations of biofilms grown in microtiter trays and on submerged glass slides showed that pgmA mutants formed roughly the same amount of biofilm as the wild type, indicating that the reduced antimicrobial tolerance of these mutants is not due to diminished biofilm formation. The pgmA gene product is known to be involved in the synthesis of precursors for cell wall components such as teichoic acids and membrane glycolipids. Accordingly, the S. mutanspgmA mutant showed increased sensitivity to Congo Red, indicating that it has impaired cell wall integrity. A changed cell wall composition of the S. mutanspgmA mutant may play a role in the increased sensitivity of S. mutanspgmA biofilms toward antibiotics.
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Affiliation(s)
- Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Svante Twetman
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
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25
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Hendiani S, Rybtke ML, Tolker-Nielsen T, Kashef N. Sub-lethal antimicrobial photodynamic inactivation affects Pseudomonas aeruginosa PAO1 quorum sensing and cyclic di-GMP regulatory systems. Photodiagnosis Photodyn Ther 2019; 27:467-473. [PMID: 31362113 DOI: 10.1016/j.pdpdt.2019.07.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/02/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Antimicrobial photodynamic inactivation (APDI) is a new therapeutic modality which needs more precision during application due to the possibility of exposure of bacteria to sub-lethal doses (sAPDI). In this study, we aimed to evaluate the effect of sAPDI on Pseudomonas aeruginosa quorum sensing (QS) and c-di-GMP signaling which are important virulence factor regulatory systems. METHODS Biofilm formation, pyoverdine, pyocyanin and protease production of P. aeruginosa was evaluated before and after a single sAPDI treatment with 0.8 mM methylene blue (MB) plus 1, 2, and 5-min irradiation with red laser light. Fluorescent lasB, rhlA, pqsA, and cdrA reporters of P. aeruginosa PAO1 and P. aeruginosa ΔmexAB-oprM were treated individually with sAPDI and the regulatory signals were detected. The gene expressions were also assessed after sAPDI using quantitative real-time PCR analysis. RESULTS Morphological observations and molecular assessments indicated that sAPDI with 0.8 mM MB along with 2- and 5-min irradiation led to an increase in the expression of the Las QS system and c-di-GMP signaling, while 1 min irradiation revealed dissimilar results (increase in lasB expression and decrease in c-di-GMP levels). Expression of rhlA and pqsA did not change in response to sAPDI. Further, a severe lethal effect of sAPDI was observed in P. aeruginosa ΔmexAB-oprM as compared with the wild type strain, whilst there was no difference in QS and c-di-GMP levels as detected by reporters between treated and untreated samples. CONCLUSION The results suggest that sAPDI affects QS and c-di-GMP signaling inP. aeruginosa in a time-dependent manner.
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Affiliation(s)
- Saghar Hendiani
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Morten Levin Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Nasim Kashef
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
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26
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Kamal SM, Rybtke ML, Nimtz M, Sperlein S, Giske C, Trček J, Deschamps J, Briandet R, Dini L, Jänsch L, Tolker-Nielsen T, Lee C, Römling U. Two FtsH Proteases Contribute to Fitness and Adaptation of Pseudomonas aeruginosa Clone C Strains. Front Microbiol 2019; 10:1372. [PMID: 31338071 PMCID: PMC6629908 DOI: 10.3389/fmicb.2019.01372] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/31/2019] [Indexed: 12/30/2022] Open
Abstract
Pseudomonas aeruginosa is an environmental bacterium and a nosocomial pathogen with clone C one of the most prevalent clonal groups. The P. aeruginosa clone C specific genomic island PACGI-1 harbors a xenolog of ftsH encoding a functionally diverse membrane-spanning ATP-dependent metalloprotease on the core genome. In the aquatic isolate P. aeruginosa SG17M, the core genome copy ftsH1 significantly affects growth and dominantly mediates a broad range of phenotypes, such as secretion of secondary metabolites, swimming and twitching motility and resistance to aminoglycosides, while the PACGI-1 xenolog ftsH2 backs up the phenotypes in the ftsH1 mutant background. The two proteins, with conserved motifs for disaggregase and protease activity present in FtsH1 and FtsH2, have the ability to form homo- and hetero-oligomers with ftsH2 distinctively expressed in the late stationary phase of growth. However, mainly FtsH1 degrades a major substrate, the heat shock transcription factor RpoH. Pull-down experiments with substrate trap-variants inactive in proteolytic activity indicate both FtsH1 and FtsH2 to interact with the inhibitory protein HflC, while the phenazine biosynthesis protein PhzC was identified as a substrate of FtsH1. In summary, as an exception in P. aeruginosa, clone C harbors two copies of the ftsH metallo-protease, which cumulatively are required for the expression of a diversity of phenotypes.
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Affiliation(s)
- Shady Mansour Kamal
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Microbiology and Immunology, Faculty of Pharmaceutical Sciences & Pharmaceutical Industries, Future University in Egypt, New Cairo, Egypt
| | - Morten Levin Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Manfred Nimtz
- Department of Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Stefanie Sperlein
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Christian Giske
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Janja Trček
- Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Julien Deschamps
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Romain Briandet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Luciana Dini
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
| | - Lothar Jänsch
- Department of Cellular Proteomics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Changhan Lee
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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27
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Ciofu O, Tolker-Nielsen T. Tolerance and Resistance of Pseudomonas aeruginosa Biofilms to Antimicrobial Agents-How P. aeruginosa Can Escape Antibiotics. Front Microbiol 2019; 10:913. [PMID: 31130925 PMCID: PMC6509751 DOI: 10.3389/fmicb.2019.00913] [Citation(s) in RCA: 351] [Impact Index Per Article: 70.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/10/2019] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is one of the six bacterial pathogens, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., which are commonly associated with antimicrobial resistance, and denoted by their acronym ESKAPE. P. aeruginosa is also recognized as an important cause of chronic infections due to its ability to form biofilms, where the bacteria are present in aggregates encased in a self-produced extracellular matrix and are difficult or impossible to eradicate with antibiotic treatment. P. aeruginosa causes chronic infections in the lungs of patients with cystic fibrosis and chronic obstructive lung disease, as well as chronic urinary tract infections in patients with permanent bladder catheter, and ventilator-associated pneumonia in intubated patients, and is also an important pathogen in chronic wounds. Antibiotic treatment cannot eradicate these biofilm infections due to their intrinsic antibiotic tolerance and the development of mutational antibiotic resistance. The tolerance of biofilms to antibiotics is multifactorial involving physical, physiological, and genetic determinants, whereas the antibiotic resistance of bacteria in biofilms is caused by mutations and driven by the repeated exposure of the bacteria to high levels of antibiotics. In this review, both the antimicrobial tolerance and the development of resistance to antibiotics in P. aeruginosa biofilms are discussed. Possible therapeutic approaches based on the understanding of the mechanisms involved in the tolerance and resistances of biofilms to antibiotics are also addressed.
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Affiliation(s)
- Oana Ciofu
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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28
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Nilsson M, Jakobsen TH, Givskov M, Twetman S, Tolker-Nielsen T. Oxidative stress response plays a role in antibiotic tolerance of Streptococcus mutans biofilms. Microbiology (Reading) 2019; 165:334-342. [PMID: 30663959 DOI: 10.1099/mic.0.000773] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Knowledge about biofilm-associated antibiotic tolerance mechanisms is warranted in order to develop effective treatments against biofilm infections. We performed a screen of a Streptococcus mutans transposon mutant library for mutants with reduced biofilm-associated antimicrobial tolerance, and found that the spxA1 gene plays a role in tolerance towards gentamicin and other antibiotics such as vancomycin and linezolid. SpxA1 is a regulator of genes involved in the oxidative stress response in S. mutans. The oxidative stress response genes gor and ahpC were found to be up-regulated upon antibiotic treatment of S. mutans wild-type biofilms, but not spxA1 mutant biofilms. The gor gene product catalyses the formation of glutathione which functions as an important antioxidant during oxidative stress, and accordingly biofilm-associated antibiotic tolerance of the spxA1 mutant could be restored by exogenous addition of glutathione. Our results indicate that the oxidative stress response plays a role in biofilm-associated antibiotic tolerance of S. mutans, and add to the on-going debate on the role of reactive oxygen species in antibiotic mediated killing of bacteria.
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Affiliation(s)
- Martin Nilsson
- 1Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- 1Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- 1Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- 2Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Svante Twetman
- 3Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- 1Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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29
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Almblad H, Rybtke M, Hendiani S, Andersen JB, Givskov M, Tolker-Nielsen T. High levels of cAMP inhibit Pseudomonas aeruginosa biofilm formation through reduction of the c-di-GMP content. Microbiology (Reading) 2019; 165:324-333. [PMID: 30663958 DOI: 10.1099/mic.0.000772] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The human pathogen Pseudomonas aeruginosa can cause both acute infections and chronic biofilm-based infections. Expression of acute virulence factors is positively regulated by cAMP, whereas biofilm formation is positively regulated by c-di-GMP. We provide evidence that increased levels of cAMP, caused by either a lack of degradation or increased production, inhibit P. aeruginosa biofilm formation. cAMP-mediated inhibition of P. aeruginosa biofilm formation required Vfr, and involved a reduction of the level of c-di-GMP, as well as reduced production of biofilm matrix components. A mutant screen and characterization of defined knockout mutants suggested that a subset of c-di-GMP-degrading phosphodiesterases is involved in cAMP-Vfr-mediated biofilm inhibition in P. aeruginosa.
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Affiliation(s)
- Henrik Almblad
- 1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,‡Present address: Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Morten Rybtke
- 1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Saghar Hendiani
- 2Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Jens Bo Andersen
- 1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- 1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,3Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Tim Tolker-Nielsen
- 1Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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30
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Richter AM, Fazli M, Schmid N, Shilling R, Suppiger A, Givskov M, Eberl L, Tolker-Nielsen T. Key Players and Individualists of Cyclic-di-GMP Signaling in Burkholderia cenocepacia. Front Microbiol 2019; 9:3286. [PMID: 30687272 PMCID: PMC6335245 DOI: 10.3389/fmicb.2018.03286] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/17/2018] [Indexed: 12/19/2022] Open
Abstract
Burkholderia cenocepacia H111 is an opportunistic pathogen associated with chronic lung infections in cystic fibrosis patients. Biofilm formation, motility and virulence of B. cenocepacia are regulated by the second messenger cyclic di-guanosine monophosphate (c-di-GMP). In the present study, we analyzed the role of all 25 putative c-di-GMP metabolizing proteins of B. cenocepacia H111 with respect to motility, colony morphology, pellicle formation, biofilm formation, and virulence. We found that RpfR is a key regulator of c-di-GMP signaling in B. cenocepacia, affecting a broad spectrum of phenotypes under various environmental conditions. In addition, we identified Bcal2449 as a regulator of B. cenocepacia virulence in Galleria mellonella larvae. While Bcal2449 consists of protein domains that may catalyze both c-di-GMP synthesis and degradation, only the latter was essential for larvae killing, suggesting that a decreased c-di-GMP level mediated by the Bcal2449 protein is required for virulence of B. cenocepacia. Finally, our work suggests that some individual proteins play a role in regulating exclusively motility (CdpA), biofilm formation (Bcam1160) or both (Bcam2836).
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Affiliation(s)
- Anja M Richter
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mustafa Fazli
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nadine Schmid
- Department of Microbiology, University of Zurich, Zurich, Switzerland
| | - Rebecca Shilling
- Department of Microbiology, University of Zurich, Zurich, Switzerland
| | - Angela Suppiger
- Department of Microbiology, University of Zurich, Zurich, Switzerland
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Leo Eberl
- Department of Microbiology, University of Zurich, Zurich, Switzerland
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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31
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Kwon HY, Kim JY, Liu X, Lee JY, Yam JKH, Dahl Hultqvist L, Xu W, Rybtke M, Tolker-Nielsen T, Heo W, Kim JJ, Kang NY, Joo T, Yang L, Park SJ, Givskov M, Chang YT. Visualizing biofilm by targeting eDNA with long wavelength probe CDr15. Biomater Sci 2019; 7:3594-3598. [DOI: 10.1039/c9bm00152b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We developed a small molecule CDr15, which has eDNA selectivity of bacterial biofilm.
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32
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Abstract
Mutant libraries, generated by transposons and screened for various phenotypes, have led to many important discoveries regarding gene functions in various organisms. In this chapter we describe the use of plasmid pMN100, a transposon vector constructed to perform in vivo transposition primarily in oral streptococci. Compared to in vitro transposition systems the conditional replicative features of the plasmid, and the inducible expression of the mariner Himar1 transposase, makes pMN100 particularly useful for bacterial strains showing a low transformation frequency. We outline how to transform plasmid pMN100 into Streptococcus mutans, carry out transposon mutagenesis, and determine the chromosomal location of inserted transposons. It is our prospect that the protocols can be used as guidelines for transposon mutagenesis in S. mutans as well as other species of streptococci.
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Affiliation(s)
- Martin Nilsson
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark.,Singapore Center for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark.
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33
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Kwon HY, Kim JY, Lee JY, Yam JKH, Hultqvist LD, Xu W, Rybtke M, Tolker-Nielsen T, Kim JJ, Kang NY, Yang L, Park SJ, Givskov M, Chang YT. CDy14: a novel biofilm probe targeting exopolysaccharide Psl. Chem Commun (Camb) 2018; 54:11865-11868. [DOI: 10.1039/c8cc05544k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We developed CDy14, which is the first small molecule probe for Psl target in bacterial biofilm.
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Affiliation(s)
- Haw-Young Kwon
- Center for Self-assembly and Complexity, Institute for Basic Science (IBS)
- Pohang 37673
- Republic of Korea
| | - Jun-Young Kim
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research
- Singapore
| | - Jung Yeol Lee
- New drug discovery Center, Daegu-Gyeongbuk Medivalley Innovation Foundation (DGMIF)
- Daegu
- Republic of Korea
| | - Joey Kuok Hoong Yam
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University
- Singapore
| | - Louise Dahl Hultqvist
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen
- DK-2200 Copenhagen
- Denmark
| | - Wang Xu
- Department of Chemistry & Med Chem Program, Life Sciences Institute, National University of Singapore
- Singapore
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen
- DK-2200 Copenhagen
- Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen
- DK-2200 Copenhagen
- Denmark
| | - Jong-Jin Kim
- Center for Self-assembly and Complexity, Institute for Basic Science (IBS)
- Pohang 37673
- Republic of Korea
| | - Nam-Young Kang
- New drug discovery Center, Daegu-Gyeongbuk Medivalley Innovation Foundation (DGMIF)
- Daegu
- Republic of Korea
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University
- Singapore
| | - Sung-Jin Park
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research
- Singapore
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University
- Singapore
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen
- DK-2200 Copenhagen
- Denmark
| | - Young-Tae Chang
- Center for Self-assembly and Complexity, Institute for Basic Science (IBS)
- Pohang 37673
- Republic of Korea
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research
- Singapore
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34
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Lin Chua S, Liu Y, Li Y, Jun Ting H, Kohli GS, Cai Z, Suwanchaikasem P, Kau Kit Goh K, Pin Ng S, Tolker-Nielsen T, Yang L, Givskov M. Reduced Intracellular c-di-GMP Content Increases Expression of Quorum Sensing-Regulated Genes in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2017; 7:451. [PMID: 29090193 PMCID: PMC5650985 DOI: 10.3389/fcimb.2017.00451] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/04/2017] [Indexed: 01/08/2023] Open
Abstract
Cyclic-di-GMP (c-di-GMP) is an intracellular secondary messenger which controls the biofilm life cycle in many bacterial species. High intracellular c-di-GMP content enhances biofilm formation via the reduction of motility and production of biofilm matrix, while low c-di-GMP content in biofilm cells leads to increased motility and biofilm dispersal. While the effect of high c-di-GMP levels on bacterial lifestyles is well studied, the physiology of cells at low c-di-GMP levels remains unclear. Here, we showed that Pseudomonas aeruginosa cells with high and low intracellular c-di-GMP contents possessed distinct transcriptome profiles. There were 535 genes being upregulated and 432 genes downregulated in cells with low c-di-GMP, as compared to cells with high c-di-GMP. Interestingly, both rhl and pqs quorum-sensing (QS) operons were expressed at higher levels in cells with low intracellular c-di-GMP content compared with cells with higher c-di-GMP content. The induced expression of pqs and rhl QS required a functional PqsR, the transcriptional regulator of pqs QS. Next, we observed increased production of pqs and rhl-regulated virulence factors, such as pyocyanin and rhamnolipids, in P. aeruginosa cells with low c-di-GMP levels, conferring them with increased intracellular survival rates and cytotoxicity against murine macrophages. Hence, our data suggested that low intracellular c-di-GMP levels in bacteria could induce QS-regulated virulence, in particular rhamnolipids that cripple the cellular components of the innate immune system.
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Affiliation(s)
- Song Lin Chua
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Yang Liu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Yingying Li
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Hui Jun Ting
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Gurjeet S Kohli
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Zhao Cai
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Pipob Suwanchaikasem
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Kelvin Kau Kit Goh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Sean Pin Ng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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35
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Jakobsen TH, Tolker-Nielsen T, Givskov M. Bacterial Biofilm Control by Perturbation of Bacterial Signaling Processes. Int J Mol Sci 2017; 18:ijms18091970. [PMID: 28902153 PMCID: PMC5618619 DOI: 10.3390/ijms18091970] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 01/20/2023] Open
Abstract
The development of effective strategies to combat biofilm infections by means of either mechanical or chemical approaches could dramatically change today’s treatment procedures for the benefit of thousands of patients. Remarkably, considering the increased focus on biofilms in general, there has still not been invented and/or developed any simple, efficient and reliable methods with which to “chemically” eradicate biofilm infections. This underlines the resilience of infective agents present as biofilms and it further emphasizes the insufficiency of today’s approaches used to combat chronic infections. A potential method for biofilm dismantling is chemical interception of regulatory processes that are specifically involved in the biofilm mode of life. In particular, bacterial cell to cell signaling called “Quorum Sensing” together with intracellular signaling by bis-(3′-5′)-cyclic-dimeric guanosine monophosphate (cyclic-di-GMP) have gained a lot of attention over the last two decades. More recently, regulatory processes governed by two component regulatory systems and small non-coding RNAs have been increasingly investigated. Here, we review novel findings and potentials of using small molecules to target and modulate these regulatory processes in the bacterium Pseudomonas aeruginosa to decrease its pathogenic potential.
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Affiliation(s)
- Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore.
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36
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Schmid N, Suppiger A, Steiner E, Pessi G, Kaever V, Fazli M, Tolker-Nielsen T, Jenal U, Eberl L. High intracellular c-di-GMP levels antagonize quorum sensing and virulence gene expression in Burkholderia cenocepacia H111. Microbiology (Reading) 2017; 163:754-764. [PMID: 28463102 DOI: 10.1099/mic.0.000452] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The opportunistic human pathogen Burkholderia cenocepacia H111 uses two chemically distinct signal molecules for controlling gene expression in a cell density-dependent manner: N-acyl-homoserine lactones (AHLs) and cis-2-dodecenoic acid (BDSF). Binding of BDSF to its cognate receptor RpfR lowers the intracellular c-di-GMP level, which in turn leads to differential expression of target genes. In this study we analysed the transcriptional profile of B. cenocepacia H111 upon artificially altering the cellular c-di-GMP level. One hundred and eleven genes were shown to be differentially expressed, 96 of which were downregulated at a high c-di-GMP concentration. Our analysis revealed that the BDSF, AHL and c-di-GMP regulons overlap for the regulation of 24 genes and that a high c-di-GMP level suppresses expression of AHL-regulated genes. Phenotypic analyses confirmed changes in the expression of virulence factors, the production of AHL signal molecules and the biosynthesis of different biofilm matrix components upon altered c-di-GMP levels. We also demonstrate that the intracellular c-di-GMP level determines the virulence of B. cenocepacia to Caenorhabditis elegans and Galleria mellonella.
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Affiliation(s)
- Nadine Schmid
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Angela Suppiger
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Elisabeth Steiner
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gabriella Pessi
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Mustafa Fazli
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Urs Jenal
- Focal Area of Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Leo Eberl
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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37
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Fazli M, Rybtke M, Steiner E, Weidel E, Berthelsen J, Groizeleau J, Bin W, Zhi BZ, Yaming Z, Kaever V, Givskov M, Hartmann RW, Eberl L, Tolker-Nielsen T. Regulation of Burkholderia cenocepacia biofilm formation by RpoN and the c-di-GMP effector BerB. Microbiologyopen 2017; 6. [PMID: 28419759 PMCID: PMC5552954 DOI: 10.1002/mbo3.480] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/01/2017] [Accepted: 03/07/2017] [Indexed: 11/25/2022] Open
Abstract
Knowledge about the molecular mechanisms that are involved in the regulation of biofilm formation is essential for the development of biofilm‐control measures. It is well established that the nucleotide second messenger cyclic diguanosine monophosphate (c‐di‐GMP) is a positive regulator of biofilm formation in many bacteria, but more knowledge about c‐di‐GMP effectors is needed. We provide evidence that c‐di‐GMP, the alternative sigma factor RpoN (σ54), and the enhancer‐binding protein BerB play a role in biofilm formation of Burkholderia cenocepacia by regulating the production of a biofilm‐stabilizing exopolysaccharide. Our findings suggest that BerB binds c‐di‐GMP, and activates RpoN‐dependent transcription of the berA gene coding for a c‐di‐GMP‐responsive transcriptional regulator. An increased level of the BerA protein in turn induces the production of biofilm‐stabilizing exopolysaccharide in response to high c‐di‐GMP levels. Our findings imply that the production of biofilm exopolysaccharide in B. cenocepacia is regulated through a cascade involving two consecutive transcription events that are both activated by c‐di‐GMP. This type of regulation may allow tight control of the expenditure of cellular resources.
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Affiliation(s)
- Mustafa Fazli
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisabeth Steiner
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Elisabeth Weidel
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany
| | - Jens Berthelsen
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Julie Groizeleau
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Wu Bin
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Boo Zhao Zhi
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zhang Yaming
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Michael Givskov
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Rolf W Hartmann
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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38
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Ring HC, Bay L, Nilsson M, Kallenbach K, Miller IM, Saunte DM, Bjarnsholt T, Tolker-Nielsen T, Jemec GB. Bacterial biofilm in chronic lesions of hidradenitis suppurativa. Br J Dermatol 2017; 176:993-1000. [PMID: 27564400 DOI: 10.1111/bjd.15007] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Chronic nonhealing or recurrent inflammatory lesions, reminiscent of infection but recalcitrant to antibiotic therapy, generally characterize biofilm-driven diseases. Chronic lesions of hidradenitis suppurativa (HS) exhibit several characteristics, which are compatible with well-known biofilm infections. OBJECTIVES To determine and quantify the potential presence of bacterial aggregates in chronic HS lesions. METHODS In 42 consecutive patients with HS suffering from chronic lesions, biopsies were obtained from lesional as well as from perilesional skin. Samples were investigated using peptide nucleic acid-fluorescence in situ hybridization in combination with confocal laser scanning microscopy. In addition, corresponding histopathological analysis on haematoxylin and eosin slides was performed. RESULTS Biofilms were seen in 67% of the samples of chronic lesions and in 75% of the perilesional samples. The mean diameter of aggregates in lesional skin was significantly greater than in perilesional skin (P = 0·01). Large biofilms (aggregates > 50 μm in diameter) were found in 42% of lesional samples and in only 5% of the perilesional samples (P = 0·009). The majority of the large biofilms were situated in sinus tracts (63%) or in the infundibulum (37%). The majority of the sinus tract samples (73%) contained active bacterial cells, which were associated with inflammation. CONCLUSIONS This study suggests that biofilm formation is associated with inflammation of chronic HS lesions. The aggregates most likely occur as a secondary event, possibly due to predisposing local anatomical changes such as sinus tracts (tunnels), keratinous detritus and dilated hair follicles.
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Affiliation(s)
- H C Ring
- Department of Dermatology, Zealand University Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, Denmark
| | - L Bay
- Department of Immunology and Microbiology, Costerton Biofilm Centre, University of Copenhagen, Denmark
| | - M Nilsson
- Department of Immunology and Microbiology, Costerton Biofilm Centre, University of Copenhagen, Denmark
| | - K Kallenbach
- Department of Pathology, Zealand University Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, Denmark
| | - I M Miller
- Department of Dermatology, Zealand University Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, Denmark
| | - D M Saunte
- Department of Dermatology, Zealand University Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, Denmark
| | - T Bjarnsholt
- Department of Immunology and Microbiology, Costerton Biofilm Centre, University of Copenhagen, Denmark.,Department for Clinical Microbiology, Section 9301, Copenhagen University Hospital, Denmark
| | - T Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Centre, University of Copenhagen, Denmark
| | - G B Jemec
- Department of Dermatology, Zealand University Hospital, Health Sciences Faculty, University of Copenhagen, Roskilde, Denmark
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39
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Hansen GM, Belstrøm D, Nilsson M, Helqvist S, Nielsen CH, Holmstrup P, Tolker-Nielsen T, Givskov M, Hansen PR. Pseudomonas aeruginosa Microcolonies in Coronary Thrombi from Patients with ST-Segment Elevation Myocardial Infarction. PLoS One 2016; 11:e0168771. [PMID: 28030624 PMCID: PMC5193428 DOI: 10.1371/journal.pone.0168771] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/06/2016] [Indexed: 12/24/2022] Open
Abstract
Chronic infection is associated with an increased risk of atherothrombotic disease and direct bacterial infection of arteries has been suggested to contribute to the development of unstable atherosclerotic plaques. In this study, we examined coronary thrombi obtained in vivo from patients with ST-segment elevation myocardial infarction (STEMI) for the presence of bacterial DNA and bacteria. Aspirated coronary thrombi from 22 patients with STEMI were collected during primary percutaneous coronary intervention and arterial blood control samples were drawn from radial or femoral artery sheaths. Analyses were performed using 16S polymerase chain reaction and with next-generation sequencing to determine bacterial taxonomic classification. In selected thrombi with the highest relative abundance of Pseudomonas aeruginosa DNA, peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) with universal and species specific probes was performed to visualize bacteria within thrombi. From the taxonomic analysis we identified a total of 55 different bacterial species. DNA from Pseudomonas aeruginosa represented the only species that was significantly associated with either thrombi or blood and was >30 times more abundant in thrombi than in arterial blood (p<0.0001). Whole and intact bacteria present as biofilm microcolonies were detected in selected thrombi using universal and P. aeruginosa-specific PNA-FISH probes. P. aeruginosa and vascular biofilm infection in culprit lesions may play a role in STEMI, but causal relationships remain to be determined.
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Affiliation(s)
- Gorm Mørk Hansen
- Department of Cardiology, Herlev and Gentofte University Hospital, Copenhagen, Denmark
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
- * E-mail:
| | - Daniel Belstrøm
- Section of Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Steffen Helqvist
- Department of Cardiology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Claus Henrik Nielsen
- Institute for Inflammation Research, Department of Infectious Diseases and Rheumatology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Palle Holmstrup
- Section of Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
- Singapore Center on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore
| | - Peter Riis Hansen
- Department of Cardiology, Herlev and Gentofte University Hospital, Copenhagen, Denmark
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40
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Groizeleau J, Rybtke M, Andersen JB, Berthelsen J, Liu Y, Yang L, Nielsen TE, Kaever V, Givskov M, Tolker-Nielsen T. The anti-cancerous drug doxorubicin decreases the c-di-GMP content in Pseudomonas aeruginosa but promotes biofilm formation. Microbiology (Reading) 2016; 162:1797-1807. [PMID: 27526691 DOI: 10.1099/mic.0.000354] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Current antibiotic treatments are insufficient in eradicating bacterial biofilms, which represent the primary cause of chronic bacterial infections. Thus, there is an urgent need for new strategies to eradicate biofilm infections. The second messenger c-di-GMP is a positive regulator of biofilm formation in many clinically relevant bacteria. It is hypothesized that drugs lowering the intracellular level of c-di-GMP will force biofilm bacteria into a more treatable planktonic lifestyle. To identify compounds capable of lowering c-di-GMP levels in Pseudomonas aeruginosa, we screened 5000 compounds for their potential c-di-GMP-lowering effect using a recently developed c-di-GMP biosensor strain. Our screen identified the anti-cancerous drug doxorubicin as a potent c-di-GMP inhibitor. In addition, the drug decreased the transcription of many biofilm-related genes. However, despite its effect on the c-di-GMP content in P. aeruginosa, doxorubicin was unable to inhibit biofilm formation or disperse established biofilms. On the contrary, the drug was found to promote P. aeruginosa biofilm formation, possibly through release of extracellular DNA from a subpopulation of killed bacteria. Our findings emphasize that lowering of the c-di-GMP content in bacteria might not be sufficient to mediate biofilm inhibition or dispersal.
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Affiliation(s)
- Julie Groizeleau
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Berthelsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yang Liu
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Liang Yang
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Thomas E Nielsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Michael Givskov
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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41
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Hansen GM, Nilsson M, Nielsen CH, Holmstrup P, Helqvist S, Tolker-Nielsen T, Givskov M, Hansen PR. Absence of Bacteria on Coronary Angioplasty Balloons from Unselected Patients: Results with Use of a High Sensitivity Polymerase Chain Reaction Assay. PLoS One 2015; 10:e0145657. [PMID: 26695491 PMCID: PMC4690592 DOI: 10.1371/journal.pone.0145657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 12/07/2015] [Indexed: 01/01/2023] Open
Abstract
Periodontitis is a chronic, bacterially-induced inflammatory disease of the tooth-supporting tissues, which may result in transient bacteremia and a systemic inflammatory response. Periodontitis is associated with coronary artery disease independently of established cardiovascular risk factors, and translocation of bacteria from the oral cavity to the coronary arteries may play a role in the development of coronary artery disease. Very few studies have used angioplasty balloons for in vivo sampling from diseased coronary arteries, and with varying results. Therefore, the aim of this study was to assess if bacterial DNA from primarily oral bacteria could be detected on coronary angioplasty balloons by use of an optimized sampling process combined with an internally validated sensitive polymerase chain reaction (PCR) assay. Coronary angioplasty balloons and control samples from a total of 45 unselected patients with stable angina, unstable angina/non-ST elevation myocardial infarction, and ST-elevation myocardial infarction (n = 15 in each group) were collected and analyzed using a PCR assay with high sensitivity and specificity for 16S rRNA genes of the oral microbiome. Despite elimination of extraction and purification steps, and demonstration of sensitivity levels of 25–125 colony forming units (CFU), we did not detect bacterial DNA from any of the coronary angioplasty balloons. A subsequent questionnaire indicated that the prevalence of periodontitis in the study cohort was at least 39.5%. Although coronary angioplasty balloons are unlikely to be useful for detection of bacteria with current PCR techniques in unselected patients with coronary artery disease, more studies are warranted to determine the extent to which bacteria contribute to atherosclerosis and its clinical manifestations and whether the presence of bacteria in the arteries is a transient phenomenon.
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Affiliation(s)
- Gorm Mørk Hansen
- Department of Cardiology, Gentofte University Hospital, Hellerup, Denmark.,Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Claus Henrik Nielsen
- Institute for Inflammation Research, Department of Infectious Diseases and Rheumatology, Rigshospitalet, Copenhagen, Denmark.,Section of Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Palle Holmstrup
- Section of Periodontology, Department of Odontology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Steffen Helqvist
- Department of Cardiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Copenhagen University, Copenhagen, Denmark.,Singapore Center on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore
| | - Peter Riis Hansen
- Department of Cardiology, Gentofte University Hospital, Hellerup, Denmark
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42
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Rybtke M, Hultqvist LD, Givskov M, Tolker-Nielsen T. Pseudomonas aeruginosa Biofilm Infections: Community Structure, Antimicrobial Tolerance and Immune Response. J Mol Biol 2015; 427:3628-45. [DOI: 10.1016/j.jmb.2015.08.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 02/07/2023]
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43
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Rybtke M, Berthelsen J, Yang L, Høiby N, Givskov M, Tolker-Nielsen T. The LapG protein plays a role in Pseudomonas aeruginosa biofilm formation by controlling the presence of the CdrA adhesin on the cell surface. Microbiologyopen 2015; 4:917-30. [PMID: 26458733 PMCID: PMC4694147 DOI: 10.1002/mbo3.301] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 01/06/2023] Open
Abstract
Pseudomonas aeruginosa is a clinically relevant species involved in biofilm-based chronic infections. We provide evidence that the P. aeruginosa LapG protein functions as a periplasmic protease that can cleave the protein adhesin CdrA off the cell surface, and thereby plays a role in biofilm formation and biofilm dispersal. The P. aeruginosa LapG protein is shown to be a functional homolog of the Pseudomonas putida LapG protein which has previously been shown to function as a periplasmic protease that targets the surface adhesin LapA. Transposon mutagenesis and characterization of defined knockout mutants provided evidence that the CdrA adhesin is a target of LapG in P. aeruginosa. A wspF lapG double mutant was hyper-aggregating and hyper biofilm forming, whereas a wspF lapG cdrA triple mutant lost these phenotypes. In addition, western blot detection of CdrA in culture supernatants and whole-cell protein fractions showed that CdrA was retained in the whole-cell protein fraction when LapG was absent, whereas it was found in the culture supernatant when LapG was present. The finding that CdrA is a target of LapG in P. aeruginosa is surprising because CdrA has no homology to LapA.
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Affiliation(s)
- Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
| | - Jens Berthelsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
| | - Liang Yang
- Singapore Center on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Niels Høiby
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.,Singapore Center on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
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44
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Zeng G, Vad BS, Dueholm MS, Christiansen G, Nilsson M, Tolker-Nielsen T, Nielsen PH, Meyer RL, Otzen DE. Functional bacterial amyloid increases Pseudomonas biofilm hydrophobicity and stiffness. Front Microbiol 2015; 6:1099. [PMID: 26500638 PMCID: PMC4595789 DOI: 10.3389/fmicb.2015.01099] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022] Open
Abstract
The success of Pseudomonas species as opportunistic pathogens derives in great part from their ability to form stable biofilms that offer protection against chemical and mechanical attack. The extracellular matrix of biofilms contains numerous biomolecules, and it has recently been discovered that in Pseudomonas one of the components includes β-sheet rich amyloid fibrils (functional amyloid) produced by the fap operon. However, the role of the functional amyloid within the biofilm has not yet been investigated in detail. Here we investigate how the fap-based amyloid produced by Pseudomonas affects biofilm hydrophobicity and mechanical properties. Using atomic force microscopy imaging and force spectroscopy, we show that the amyloid renders individual cells more resistant to drying and alters their interactions with hydrophobic probes. Importantly, amyloid makes Pseudomonas more hydrophobic and increases biofilm stiffness 20-fold. Deletion of any one of the individual members of in the fap operon (except the putative chaperone FapA) abolishes this ability to increase biofilm stiffness and correlates with the loss of amyloid. We conclude that amyloid makes major contributions to biofilm mechanical robustness.
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Affiliation(s)
- Guanghong Zeng
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Brian S. Vad
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Morten S. Dueholm
- Center for Microbial Communities, Aalborg UniversityAalborg, Denmark
| | - Gunna Christiansen
- Department of Biomedicine-Medical Microbiology and Immunology, Aarhus UniversityAarhus, Denmark
| | - Martin Nilsson
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Per H. Nielsen
- Center for Microbial Communities, Aalborg UniversityAalborg, Denmark
| | - Rikke L. Meyer
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Daniel E. Otzen
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
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45
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Orlandi VT, Bolognese F, Chiodaroli L, Tolker-Nielsen T, Barbieri P. Pigments influence the tolerance of Pseudomonas aeruginosa PAO1 to photodynamically induced oxidative stress. Microbiology (Reading) 2015; 161:2298-309. [PMID: 26419906 DOI: 10.1099/mic.0.000193] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen known to be resistant to different classes of antibiotics and disinfectants. P. aeruginosa also displays a certain degree of tolerance to photodynamic therapy (PDT), an alternative antimicrobial approach exploiting a photo-oxidative stress induced by exogenous photosensitizers and visible light. To evaluate whether P. aeruginosa pigments can contribute to its relative tolerance to PDT, we analysed the response to this treatment of isogenic transposon mutants of P. aeruginosa PAO1 with altered pigmentation. In general, in the presence of pigments a higher tolerance to PDT-induced photo-oxidative stress was observed. Hyperproduction of pyomelanin makes the cells much more tolerant to stress caused by either radicals or singlet oxygen generated by different photosensitizers upon photoactivation. Phenazines, pyocyanin and phenazine-1-carboxylic acid, produced in different amounts depending on the cultural conditions, are able to counteract both types of PDT-elicited reactive oxygen species. Hyperproduction of pyoverdine, caused by a mutation in a quorum-sensing gene, rendered P. aeruginosa more tolerant to a photosensitizer that generates mainly singlet oxygen, although in this case the observed tolerance to photo-oxidative stress cannot be exclusively attributed to the presence of the pigment.
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Affiliation(s)
- Viviana T Orlandi
- 1Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Fabrizio Bolognese
- 1Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Luca Chiodaroli
- 1Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Tim Tolker-Nielsen
- 2Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Paola Barbieri
- 1Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
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46
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Bonnichsen L, Bygvraa Svenningsen N, Rybtke M, de Bruijn I, Raaijmakers JM, Tolker-Nielsen T, Nybroe O. Lipopeptide biosurfactant viscosin enhances dispersal of Pseudomonas fluorescens SBW25 biofilms. Microbiology (Reading) 2015; 161:2289-97. [PMID: 26419730 PMCID: PMC4811653 DOI: 10.1099/mic.0.000191] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pseudomonads produce several lipopeptide biosurfactants that have antimicrobial properties but that also facilitate surface motility and influence biofilm formation. Detailed studies addressing the significance of lipopeptides for biofilm formation and architecture are rare. Hence, the present study sets out to determine the specific role of the lipopeptide viscosin in Pseudomonas fluorescens SBW25 biofilm formation, architecture and dispersal, and to relate viscA gene expression to viscosin production and effect. Initially, we compared biofilm formation of SBW25 and the viscosin-deficient mutant strain SBW25ΔviscA in static microtitre assays. These experiments demonstrated that viscosin had little influence on the amount of biofilm formed by SBW25 during the early stages of biofilm development. Later, however, SBW25 formed significantly less biofilm than SBW25ΔviscA. The indication that viscosin is involved in biofilm dispersal was confirmed by chemical complementation of the mutant biofilm. Furthermore, a fluorescent bioreporter showed that viscA expression was induced in biofilms 4 h prior to dispersal. Subsequent detailed studies of biofilms formed in flow cells for up to 5 days revealed that SBW25 and SBW25ΔviscA developed comparable biofilms dominated by well-defined, mushroom-shaped structures. Carbon starvation was required to obtain biofilm dispersal in this system. Dispersal of SBW25 biofilms was significantly greater than of SBW25ΔviscA biofilms after 3 h and, importantly, carbon starvation strongly induced viscA expression, in particular for cells that were apparently leaving the biofilm. Thus, the present study points to a role for viscosin-facilitated motility in dispersal of SBW25 biofilms.
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Affiliation(s)
- Lise Bonnichsen
- 1 Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Nanna Bygvraa Svenningsen
- 1 Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- 2 Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Irene de Bruijn
- 3 Microbial Ecology Department, Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Jos M Raaijmakers
- 3 Microbial Ecology Department, Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Tim Tolker-Nielsen
- 2 Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ole Nybroe
- 1 Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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47
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Mitra S, Drautz-Moses DI, Alhede M, Maw MT, Liu Y, Purbojati RW, Yap ZH, Kushwaha KK, Gheorghe AG, Bjarnsholt T, Hansen GM, Sillesen HH, Hougen HP, Hansen PR, Yang L, Tolker-Nielsen T, Schuster SC, Givskov M. In silico analyses of metagenomes from human atherosclerotic plaque samples. Microbiome 2015; 3:38. [PMID: 26334731 PMCID: PMC4559171 DOI: 10.1186/s40168-015-0100-y] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/12/2015] [Indexed: 05/19/2023]
Abstract
BACKGROUND Through several observational and mechanistic studies, microbial infection is known to promote cardiovascular disease. Direct infection of the vessel wall, along with the cardiovascular risk factors, is hypothesized to play a key role in the atherogenesis by promoting an inflammatory response leading to endothelial dysfunction and generating a proatherogenic and prothrombotic environment ultimately leading to clinical manifestations of cardiovascular disease, e.g., acute myocardial infarction or stroke. There are many reports of microbial DNA isolation and even a few studies of viable microbes isolated from human atherosclerotic vessels. However, high-resolution investigation of microbial infectious agents from human vessels that may contribute to atherosclerosis is very limited. In spite of the progress in recent sequencing technologies, analyzing host-associated metagenomes remain a challenge. RESULTS To investigate microbiome diversity within human atherosclerotic tissue samples, we employed high-throughput metagenomic analysis on: (1) atherosclerotic plaques obtained from a group of patients who underwent endarterectomy due to recent transient cerebral ischemia or stroke. (2) Presumed stabile atherosclerotic plaques obtained from autopsy from a control group of patients who all died from causes not related to cardiovascular disease. Our data provides evidence that suggest a wide range of microbial agents in atherosclerotic plaques, and an intriguing new observation that shows these microbiota displayed differences between symptomatic and asymptomatic plaques as judged from the taxonomic profiles in these two groups of patients. Additionally, functional annotations reveal significant differences in basic metabolic and disease pathway signatures between these groups. CONCLUSIONS We demonstrate the feasibility of novel high-resolution techniques aimed at identification and characterization of microbial genomes in human atherosclerotic tissue samples. Our analysis suggests that distinct groups of microbial agents might play different roles during the development of atherosclerotic plaques. These findings may serve as a reference point for future studies in this area of research.
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Affiliation(s)
- Suparna Mitra
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
- Norwich Medical School, University of East Anglia, Norwich, UK.
- Institute of Food Research, Norwich Research Park, Norwich, UK.
| | - Daniela I Drautz-Moses
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Morten Alhede
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
| | - Myat T Maw
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Yang Liu
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Rikky W Purbojati
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Zhei H Yap
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Kavita K Kushwaha
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Alexandra G Gheorghe
- The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.
| | - Gorm M Hansen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
- Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
| | - Henrik H Sillesen
- The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Hans P Hougen
- The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Peter R Hansen
- Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
| | - Liang Yang
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
| | - Stephan C Schuster
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
| | - Michael Givskov
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
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48
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Thorsing M, Bentin T, Givskov M, Tolker-Nielsen T, Goltermann L. The bactericidal activity of β-lactam antibiotics is increased by metabolizable sugar species. Microbiology (Reading) 2015; 161:1999-2007. [PMID: 26243263 DOI: 10.1099/mic.0.000152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Here, the influence of metabolizable sugars on the susceptibility of Escherichia coli to β-lactam antibiotics was investigated. Notably, monitoring growth and survival of mono- and combination-treated planktonic cultures showed a 1000- to 10 000-fold higher antibacterial efficacy of carbenicillin and cefuroxime in the presence of certain sugars, whereas other metabolites had no effect on β-lactam sensitivity. This effect was unrelated to changes in growth rate. Light microscopy and flow cytometry profiling revealed that bacterial filaments, formed due to β-lactam-mediated inhibition of cell division, rapidly appeared upon β-lactam mono-treatment and remained stable for up to 18 h. The presence of metabolizable sugars in the medium did not change the rate of filamentation, but led to lysis of the filaments within a few hours. No lysis occurred in E. coli mutants unable to metabolize the sugars, thus establishing sugar metabolism as an important factor influencing the bactericidal outcome of β-lactam treatment. Interestingly, the effect of sugar on β-lactam susceptibility was suppressed in a strain unable to synthesize the nutrient stress alarmone (p)ppGpp. Here, to the best of our knowledge, we demonstrate for the first time a specific and significant increase in β-lactam sensitivity due to sugar metabolism in planktonic, exponentially growing bacteria, unrelated to general nutrient availability or growth rate. Understanding the mechanisms underlying the nutritional influences on antibiotic sensitivity is likely to reveal new proteins or pathways that can be targeted by novel compounds, adding to the list of pharmacodynamic adjuvants that increase the efficiency and lifespan of conventional antibiotics.
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Affiliation(s)
- Mette Thorsing
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
| | - Thomas Bentin
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark.,Singapore Center on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
| | - Lise Goltermann
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
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49
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Sun J, Marais JPJ, Khoo C, LaPlante K, Vejborg RM, Givskov M, Tolker-Nielsen T, Seeram NP, Rowley DC. Cranberry ( Vaccinium macrocarpon) oligosaccharides decrease biofilm formation by uropathogenic Escherichia coli. J Funct Foods 2015; 17:235-242. [PMID: 26613004 DOI: 10.1016/j.jff.2015.05.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The preventive effects of the American cranberry (Vaccinium macrocarpon) against urinary tract infections are supported by extensive studies which have primarily focused on its phenolic constituents. Herein, a phenolic-free carbohydrate fraction (designated cranf1b-F2) was purified from cranberry fruit using ion exchange and size exclusion chromatography. MALDI-TOF-MS analysis revealed that the cranf1b-F2 constituents are predominantly oligosaccharides possessing various degrees of polymerisation and further structural analysis (by GC-MS and NMR) revealed mainly xyloglucan and arabinan residues. In antimicrobial assays, cranf1b-F2 (at 1.25 mg/mL concentration) reduced biofilm production by the uropathogenic Escherichia coli CFT073 strain by over 50% but did not inhibit bacterial growth. Cranf1b-F2 (ranging from 0.625 - 10 mg/mL) also inhibited biofilm formation of the non-pathogenic E. coli MG1655 strain up to 60% in a concentration-dependent manner. These results suggest that cranberry oligosaccharides, in addition to its phenolic constituents, may play a role in its preventive effects against urinary tract infections.
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Affiliation(s)
- Jiadong Sun
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Jannie P J Marais
- Ocean Spray Cranberries, Inc., One Ocean Spray Drive, Lakeville-Middleboro, MA, 02349, USA
| | - Christina Khoo
- Ocean Spray Cranberries, Inc., One Ocean Spray Drive, Lakeville-Middleboro, MA, 02349, USA
| | - Kerry LaPlante
- Departments of Biomedical and Pharmaceutical Sciences and Pharmacy Practice, College of Pharmacy, University of Rhode Island, Kingston, RI, 02881, USA ; Veterans Affairs Medical Center, Providence, RI, 02908, USA
| | - Rebecca M Vejborg
- Department of Immunology and Microbiology, University of Copenhagen, DK 2200 Copenhagen N, Denmark
| | - Michael Givskov
- Department of Immunology and Microbiology, University of Copenhagen, DK 2200 Copenhagen N, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, University of Copenhagen, DK 2200 Copenhagen N, Denmark
| | - Navindra P Seeram
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - David C Rowley
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
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50
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Chua SL, Hultqvist LD, Yuan M, Rybtke M, Nielsen TE, Givskov M, Tolker-Nielsen T, Yang L. In vitro and in vivo generation and characterization of Pseudomonas aeruginosa biofilm-dispersed cells via c-di-GMP manipulation. Nat Protoc 2015; 10:1165-80. [PMID: 26158442 DOI: 10.1038/nprot.2015.067] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a global secondary bacterial messenger that controls the formation of drug-resistant multicellular biofilms. Lowering the intracellular c-di-GMP content can disperse biofilms, and it is proposed as a biofilm eradication strategy. However, freshly dispersed biofilm cells exhibit a physiology distinct from biofilm and planktonic cells, and they might have a clinically relevant role in infections. Here we present in vitro and in vivo protocols for the generation and characterization of dispersed cells from Pseudomonas aeruginosa biofilms by reducing the intracellular c-di-GMP content through modulation of phosphodiesterases (PDEs). Unlike conventional protocols that demonstrate biofilm dispersal by biomass quantification, our protocols enable physiological characterization of the dispersed cells. Biomarkers of dispersed cells are identified and quantified, serving as potential targets for treating the dispersed cells. The in vitro protocol can be completed within 4 d, whereas the in vivo protocol requires 7 d.
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Affiliation(s)
- Song Lin Chua
- 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore. [2] National University of Singapore (NUS) Graduate School of Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Louise D Hultqvist
- Department of International Health, Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mingjun Yuan
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore
| | - Morten Rybtke
- Department of International Health, Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Nielsen
- Department of International Health, Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore. [2] Department of International Health, Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Department of International Health, Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Liang Yang
- 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore. [2] School of Biological Sciences, Nanyang Technological University, Singapore
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