1
|
Weaver AA, Jia J, Cutri AR, Madukoma CS, Vaerewyck CM, Bohn PW, Shrout JD. Alkyl quinolones mediate heterogeneous colony biofilm architecture that improves community-level survival. J Bacteriol 2024; 206:e0009524. [PMID: 38564677 PMCID: PMC11025328 DOI: 10.1128/jb.00095-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024] Open
Abstract
Bacterial communities exhibit complex self-organization that contributes to their survival. To better understand the molecules that contribute to transforming a small number of cells into a heterogeneous surface biofilm community, we studied acellular aggregates, structures seen by light microscopy in Pseudomonas aeruginosa colony biofilms using light microscopy and chemical imaging. These structures differ from cellular aggregates, cohesive clusters of cells important for biofilm formation, in that they are visually distinct from cells using light microscopy and are reliant on metabolites for assembly. To investigate how these structures benefit a biofilm community we characterized three recurrent types of acellular aggregates with distinct geometries that were each abundant in specific areas of these biofilms. Alkyl quinolones (AQs) were essential for the formation of all aggregate types with AQ signatures outside the aggregates below the limit of detection. These acellular aggregates spatially sequester AQs and differentiate the biofilm space. However, the three types of aggregates showed differing properties in their size, associated cell death, and lipid content. The largest aggregate type co-localized with spatially confined cell death that was not mediated by Pf4 bacteriophage. Biofilms lacking AQs were absent of localized cell death but exhibited increased, homogeneously distributed cell death. Thus, these AQ-rich aggregates regulate metabolite accessibility, differentiate regions of the biofilm, and promote survival in biofilms.IMPORTANCEPseudomonas aeruginosa is an opportunistic pathogen with the ability to cause infection in the immune-compromised. It is well established that P. aeruginosa biofilms exhibit resilience that includes decreased susceptibility to antimicrobial treatment. This work examines the self-assembled heterogeneity in biofilm communities studying acellular aggregates, regions of condensed matter requiring alkyl quinolones (AQs). AQs are important to both virulence and biofilm formation. Aggregate structures described here spatially regulate the accessibility of these AQs, differentiate regions of the biofilm community, and despite their association with autolysis, correlate with improved P. aeruginosa colony biofilm survival.
Collapse
Affiliation(s)
- Abigail A. Weaver
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jin Jia
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Allison R. Cutri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Chinedu S. Madukoma
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Catherine M. Vaerewyck
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Paul W. Bohn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, USA
| | - Joshua D. Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| |
Collapse
|
2
|
Bru JL, Kasallis SJ, Chang R, Zhuo Q, Nguyen J, Pham P, Warren E, Whiteson K, Høyland-Kroghsbo NM, Limoli DH, Siryaporn A. The great divide: rhamnolipids mediate separation between P. aeruginosa and S. aureus. Front Cell Infect Microbiol 2023; 13:1245874. [PMID: 37780859 PMCID: PMC10540625 DOI: 10.3389/fcimb.2023.1245874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/23/2023] [Indexed: 10/03/2023] Open
Abstract
The interactions between bacterial species during infection can have significant impacts on pathogenesis. Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic bacterial pathogens that can co-infect hosts and cause serious illness. The factors that dictate whether one species outcompetes the other or whether the two species coexist are not fully understood. We investigated the role of surfactants in the interactions between these two species on a surface that enables P. aeruginosa to swarm. We found that P. aeruginosa swarms are repelled by colonies of clinical S. aureus isolates, creating physical separation between the two strains. This effect was abolished in mutants of S. aureus that were defective in the production of phenol-soluble modulins (PSMs), which form amyloid fibrils around wild-type S. aureus colonies. We investigated the mechanism that establishes physical separation between the two species using Imaging of Reflected Illuminated Structures (IRIS), which is a non-invasive imaging method that tracks the flow of surfactants produced by P. aeruginosa. We found that PSMs produced by S. aureus deflected the surfactant flow, which in turn, altered the direction of P. aeruginosa swarms. These findings show that rhamnolipids mediate physical separation between P. aeruginosa and S. aureus, which could facilitate coexistence between these species. Additionally, we found that a number of molecules repelled P. aeruginosa swarms, consistent with a surfactant deflection mechanism. These include Bacillus subtilis surfactant, the fatty acids oleic acid and linoleic acid, and the synthetic lubricant polydimethylsiloxane. Lung surfactant repelled P. aeruginosa swarms and inhibited swarm expansion altogether at higher concentration. Our results suggest that surfactant interactions could have major impacts on bacteria-bacteria and bacteria-host relationships. In addition, our findings uncover a mechanism responsible for P. aeruginosa swarm development that does not rely solely on sensing but instead is based on the flow of surfactant.
Collapse
Affiliation(s)
- Jean-Louis Bru
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Summer J. Kasallis
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
- Department of Physics & Astronomy, University of California, Irvine, Irvine, CA, United States
| | - Rendell Chang
- School of Biological Sciences, University of California, Irvine, Irvine, CA, United States
| | - Quantum Zhuo
- Department of Physics & Astronomy, University of California, Irvine, Irvine, CA, United States
| | - Jacqueline Nguyen
- School of Biological Sciences, University of California, Irvine, Irvine, CA, United States
| | - Phillip Pham
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Elizabeth Warren
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
| | - Katrine Whiteson
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
| | | | - Dominique H. Limoli
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
| | - Albert Siryaporn
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
- Department of Physics & Astronomy, University of California, Irvine, Irvine, CA, United States
| |
Collapse
|
3
|
Bru JL, Kasallis SJ, Zhuo Q, Høyland-Kroghsbo NM, Siryaporn A. Swarming of P. aeruginosa: Through the lens of biophysics. BIOPHYSICS REVIEWS 2023; 4:031305. [PMID: 37781002 PMCID: PMC10540860 DOI: 10.1063/5.0128140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 08/29/2023] [Indexed: 10/03/2023]
Abstract
Swarming is a collective flagella-dependent movement of bacteria across a surface that is observed across many species of bacteria. Due to the prevalence and diversity of this motility modality, multiple models of swarming have been proposed, but a consensus on a general mechanism for swarming is still lacking. Here, we focus on swarming by Pseudomonas aeruginosa due to the abundance of experimental data and multiple models for this species, including interpretations that are rooted in biology and biophysics. In this review, we address three outstanding questions about P. aeruginosa swarming: what drives the outward expansion of a swarm, what causes the formation of dendritic patterns (tendrils), and what are the roles of flagella? We review models that propose biologically active mechanisms including surfactant sensing as well as fluid mechanics-based models that consider swarms as thin liquid films. Finally, we reconcile recent observations of P. aeruginosa swarms with early definitions of swarming. This analysis suggests that mechanisms associated with sliding motility have a critical role in P. aeruginosa swarm formation.
Collapse
Affiliation(s)
- Jean-Louis Bru
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California 92697, USA
| | - Summer J. Kasallis
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | - Quantum Zhuo
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | | | | |
Collapse
|
4
|
Jia J, Parmar D, Ellis JF, Cao T, Cutri AR, Shrout JD, Sweedler JV, Bohn PW. Effect of Micro-Patterned Mucin on Quinolone and Rhamnolipid Profiles of Mucoid Pseudomonas aeruginosa under Antibiotic Stress. ACS Infect Dis 2023; 9:150-161. [PMID: 36538577 PMCID: PMC10116410 DOI: 10.1021/acsinfecdis.2c00519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is commonly implicated in hospital-acquired infections where its capacity to form biofilms on a variety of surfaces and the resulting enhanced antibiotic resistance seriously limit treatment choices. Because surface attachment sensitizes P. aeruginosa to quorum sensing (QS) and induces virulence through both chemical and mechanical cues, we investigate the effect of surface properties through spatially patterned mucin, combined with sub-inhibitory concentrations of tobramycin on QS and virulence factors in both mucoid and non-mucoid P. aeruginosa strains using multi-modal chemical imaging combining confocal Raman microscopy and matrix-assisted laser desorption/ionization-mass spectrometry. Samples comprise surface-adherent static biofilms at a solid-water interface, supernatant liquid, and pellicle biofilms at an air-water interface at various time points. Although the presence of a sub-inhibitory concentration of tobramycin in the supernatant retards growth and development of static biofilms independent of strain and surface mucin patterning, we observe clear differences in the behavior of mucoid and non-mucoid strains. Quinolone signals in a non-mucoid strain are induced earlier and are influenced by mucin surface patterning to a degree not exhibited in the mucoid strain. Additionally, phenazine virulence factors, such as pyocyanin, are observed in the pellicle biofilms of both mucoid and non-mucoid strains but are not detected in the static biofilms from either strain, highlighting the differences in stress response between pellicle and static biofilms. Differences between mucoid and non-mucoid strains are consistent with their strain-specific phenology, in which the mucoid strain develops highly protected biofilms.
Collapse
Affiliation(s)
- Jin Jia
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Dharmeshkumar Parmar
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Joanna F Ellis
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Tianyuan Cao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Allison R Cutri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Joshua D Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jonathan V Sweedler
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Paul W Bohn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|
5
|
Constantino-Teles P, Jouault A, Touqui L, Saliba AM. Role of Host and Bacterial Lipids in Pseudomonas aeruginosa Respiratory Infections. Front Immunol 2022; 13:931027. [PMID: 35860265 PMCID: PMC9289105 DOI: 10.3389/fimmu.2022.931027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is one of the most common agents of respiratory infections and has been associated with high morbidity and mortality rates. The ability of P. aeruginosa to cause severe respiratory infections results from the coordinated action of a variety of virulence factors that promote bacterial persistence in the lungs. Several of these P. aeruginosa virulence mechanisms are mediated by bacterial lipids, mainly lipopolysaccharide, rhamnolipid, and outer membrane vesicles. Other mechanisms arise from the activity of P. aeruginosa enzymes, particularly ExoU, phospholipase C, and lipoxygenase A, which modulate host lipid signaling pathways. Moreover, host phospholipases, such as cPLA2α and sPLA2, are also activated during the infectious process and play important roles in P. aeruginosa pathogenesis. These mechanisms affect key points of the P. aeruginosa-host interaction, such as: i) biofilm formation that contributes to bacterial colonization and survival, ii) invasion of tissue barriers that allows bacterial dissemination, iii) modulation of inflammatory responses, and iv) escape from host defenses. In this mini-review, we present the lipid-based mechanism that interferes with the establishment of P. aeruginosa in the lungs and discuss how bacterial and host lipids can impact the outcome of P. aeruginosa respiratory infections.
Collapse
Affiliation(s)
- Pamella Constantino-Teles
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Albane Jouault
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Lhousseine Touqui
- Sorbonne Université, Centre de Recherche Saint-Antoine, Inserm, Institut Pasteur, Mucoviscidose et Bronchopathies Chroniques, Département Santé Globale, Paris, France
| | - Alessandra Mattos Saliba
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
- *Correspondence: Alessandra Mattos Saliba,
| |
Collapse
|
6
|
Gdaniec BG, Bonini F, Prodon F, Braschler T, Köhler T, van Delden C. Pseudomonas aeruginosa rhamnolipid micelles deliver toxic metabolites and antibiotics into Staphylococcus aureus. iScience 2022; 25:103669. [PMID: 35028539 PMCID: PMC8741607 DOI: 10.1016/j.isci.2021.103669] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/05/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Efficient delivery of toxic compounds to bacterial competitors is essential during interspecies microbial warfare. Rhamnolipids (RLPs) are glycolipids produced by Pseudomonas and Burkholderia species involved in solubilization and uptake of environmental aliphatic hydrocarbons and perform as biosurfactants for swarming motility. Here, we show that RLPs produced by Pseudomonas aeruginosa associate to form micelles. Using high-resolution microscopy, we found that RLP micelles serve as carriers for self-produced toxic compounds, which they deliver to Staphylococcus aureus cells, thereby enhancing and accelerating S. aureus killing. RLPs also potentiated the activity of lincosamide antibiotics, suggesting that RLP micelles may transport not only self-produced but also heterologous compounds to target competing bacterial species Pseudomonas aeruginosa rhamnolipids form micelles Rhamnolipid micelles delivery pyochelin into S. aureus cells Rhamnolipid micelles potentiate activity of lincosamide antibiotics against S. aureus
Collapse
Affiliation(s)
- Bartosz Gerard Gdaniec
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland.,Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Fabien Bonini
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - François Prodon
- Bioimaging Core Facility, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Thomas Braschler
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Thilo Köhler
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Christian van Delden
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| |
Collapse
|
7
|
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] [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.
Collapse
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)
| |
Collapse
|
8
|
Oziat J, Cohu T, Elsen S, Gougis M, Malliaras GG, Mailley P. Electrochemical detection of redox molecules secreted by Pseudomonas aeruginosa - Part 1: Electrochemical signatures of different strains. Bioelectrochemistry 2021; 140:107747. [PMID: 33618190 DOI: 10.1016/j.bioelechem.2021.107747] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/07/2021] [Accepted: 01/10/2021] [Indexed: 10/22/2022]
Abstract
During infections, fast identification of the microorganisms is critical to improve patient treatment and to better manage antibiotics use. Electrochemistry exhibits several advantages for rapid diagnostic: it enables easy, cheap and in situ analysis of redox molecules in most liquids. In this work, several culture supernatants of different Pseudomonas aeruginosa strains (including PAO1 and its isogenic mutants PAO1ΔpqsA, PA14, PAK and CHA) were analyzed by square wave voltammetry on glassy carbon electrode during the bacterial growth. The obtained voltamograms shown complex traces exhibiting numerous redox peaks with potential repartitions and current amplitudes depending on the studied bacterium and/or growth time. Among them, some peaks were clearly associated to the well-known redox toxin Pyocyanin (PYO) and the autoinducer Pseudomonas Quinolone Signal (PQS). Other peaks were observed that are not yet attributed to known secreted species. Each complex electrochemical response (number of peaks, peak potential and amplitude) can be interpreted as a fingerprint or "ID-card" of the studied strain that may be implemented for fast bacteria strain identification.
Collapse
Affiliation(s)
- Julie Oziat
- Univ. Grenoble-Alpes, CEA Leti, MINATEC Campus, F-38054 Grenoble, France; Department of Bioelectronics, Ecole Nationale Supérieure des Mines de Saint-Etienne, F-13541 Gardanne, France; Bioserenity, Institut du Cerveau et de la Moelle Epinière, 47 Bd de l'Hôpital, 75013 Paris, France
| | - Thibaut Cohu
- Univ. Grenoble-Alpes, CEA Leti, MINATEC Campus, F-38054 Grenoble, France
| | - Sylvie Elsen
- UMR 1036, INSERM-CEA-UJF, CNRS ERL5261, BIG, CEA-Grenoble, F-38054 Grenoble, France
| | - Maxime Gougis
- Univ. Grenoble-Alpes, CEA Leti, MINATEC Campus, F-38054 Grenoble, France
| | - George G Malliaras
- Department of Bioelectronics, Ecole Nationale Supérieure des Mines de Saint-Etienne, F-13541 Gardanne, France; Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK
| | - Pascal Mailley
- Univ. Grenoble-Alpes, CEA Leti, MINATEC Campus, F-38054 Grenoble, France.
| |
Collapse
|
9
|
Bacterial Alkyl-4-quinolones: Discovery, Structural Diversity and Biological Properties. Molecules 2020; 25:molecules25235689. [PMID: 33276615 PMCID: PMC7731028 DOI: 10.3390/molecules25235689] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022] Open
Abstract
The alkyl-4-quinolones (AQs) are a class of metabolites produced primarily by members of the Pseudomonas and Burkholderia genera, consisting of a 4-quinolone core substituted by a range of pendant groups, most commonly at the C-2 position. The history of this class of compounds dates back to the 1940s, when a range of alkylquinolones with notable antibiotic properties were first isolated from Pseudomonas aeruginosa. More recently, it was discovered that an alkylquinolone derivative, the Pseudomonas Quinolone Signal (PQS) plays a key role in bacterial communication and quorum sensing in Pseudomonas aeruginosa. Many of the best-studied examples contain simple hydrocarbon side-chains, but more recent studies have revealed a wide range of structurally diverse examples from multiple bacterial genera, including those with aromatic, isoprenoid, or sulfur-containing side-chains. In addition to their well-known antimicrobial properties, alkylquinolones have been reported with antimalarial, antifungal, antialgal, and antioxidant properties. Here we review the structural diversity and biological activity of these intriguing metabolites.
Collapse
|
10
|
Depke T, Thöming JG, Kordes A, Häussler S, Brönstrup M. Untargeted LC-MS Metabolomics Differentiates Between Virulent and Avirulent Clinical Strains of Pseudomonas aeruginosa. Biomolecules 2020; 10:biom10071041. [PMID: 32668735 PMCID: PMC7407980 DOI: 10.3390/biom10071041] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa is a facultative pathogen that can cause, inter alia, acute or chronic pneumonia in predisposed individuals. The gram-negative bacterium displays considerable genomic and phenotypic diversity that is also shaped by small molecule secondary metabolites. The discrimination of virulence phenotypes is highly relevant to the diagnosis and prognosis of P. aeruginosa infections. In order to discover small molecule metabolites that distinguish different virulence phenotypes of P. aeruginosa, 35 clinical strains were cultivated under standard conditions, characterized in terms of virulence and biofilm phenotype, and their metabolomes were investigated by untargeted liquid chromatography-mass spectrometry. The data was both mined for individual candidate markers as well as used to construct statistical models to infer the virulence phenotype from metabolomics data. We found that clinical strains that differed in their virulence and biofilm phenotype also had pronounced divergence in their metabolomes, as underlined by 332 features that were significantly differentially abundant with fold changes greater than 1.5 in both directions. Important virulence-associated secondary metabolites like rhamnolipids, alkyl quinolones or phenazines were found to be strongly upregulated in virulent strains. In contrast, we observed little change in primary metabolism. A hitherto novel cationic metabolite with a sum formula of C12H15N2 could be identified as a candidate biomarker. A random forest model was able to classify strains according to their virulence and biofilm phenotype with an area under the Receiver Operation Characteristics curve of 0.84. These findings demonstrate that untargeted metabolomics is a valuable tool to characterize P. aeruginosa virulence, and to explore interrelations between clinically important phenotypic traits and the bacterial metabolome.
Collapse
Affiliation(s)
- Tobias Depke
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
| | - Janne Gesine Thöming
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
| | - Adrian Kordes
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
| | - Susanne Häussler
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany
- Correspondence:
| |
Collapse
|
11
|
Gdaniec BG, Allard PM, Queiroz EF, Wolfender JL, van Delden C, Köhler T. Surface sensing triggers a broad-spectrum antimicrobial response in Pseudomonas aeruginosa. Environ Microbiol 2020; 22:3572-3587. [PMID: 32573899 PMCID: PMC7496599 DOI: 10.1111/1462-2920.15139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/15/2020] [Accepted: 06/21/2020] [Indexed: 12/14/2022]
Abstract
Interspecies bacterial competition may occur via cell‐associated or secreted determinants and is key to successful niche colonization. We previously evolved Pseudomonas aeruginosa in the presence of Staphylococcus aureus and identified mutations in the Wsp surface‐sensing signalling system. Surprisingly, a ΔwspF mutant, characterized by increased c‐di‐GMP levels and biofilm formation capacity, showed potent killing activity towards S. aureus in its culture supernatant. Here, we used an unbiased metabolomic analysis of culture supernatants to identify rhamnolipids, alkyl quinoline N‐oxides and two siderophores as members of four chemical clusters, which were more abundant in the ΔwspF mutant supernatants. Killing activities were quorum‐sensing controlled but independent of c‐di‐GMP levels. Based on the metabolomic analysis, we formulated a synthetic cocktail of four compounds, showing broad‐spectrum anti‐bacterial killing, including both Gram‐positive and Gram‐negative bacteria. The combination of quorum‐sensing‐controlled killing and Wsp‐system mediated biofilm formation endows P. aeruginosa with capacities essential for niche establishment and host colonization.
Collapse
Affiliation(s)
- Bartosz Gerard Gdaniec
- Transplant Infectious Diseases Unit, University Hospital Geneva, Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Pierre-Marie Allard
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Emerson Ferreira Queiroz
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Jean-Luc Wolfender
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Christian van Delden
- Transplant Infectious Diseases Unit, University Hospital Geneva, Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Thilo Köhler
- Transplant Infectious Diseases Unit, University Hospital Geneva, Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| |
Collapse
|
12
|
Burkholderia thailandensis outer membrane vesicles exert antimicrobial activity against drug-resistant and competitor microbial species. J Microbiol 2020; 58:550-562. [DOI: 10.1007/s12275-020-0028-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 12/21/2022]
|
13
|
Soldano A, Yao H, Chandler JR, Rivera M. Inhibiting Iron Mobilization from Bacterioferritin in Pseudomonas aeruginosa Impairs Biofilm Formation Irrespective of Environmental Iron Availability. ACS Infect Dis 2020; 6:447-458. [PMID: 31898890 PMCID: PMC7076691 DOI: 10.1021/acsinfecdis.9b00398] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
Although iron is
essential for bacteria, the nutrient presents problems of toxicity
and solubility. Bacteria circumvent these problems with the aid of
iron storage proteins where Fe3+ is deposited and, when
necessary, mobilized as Fe2+ for metabolic requirements.
In Pseudomonas aeruginosa, Fe3+ is compartmentalized
in bacterioferritin (BfrB), and its mobilization as Fe2+ requires specific binding of a ferredoxin (Bfd) to reduce the stored
Fe3+. Blocking the BfrB-Bfd complex leads to irreversible
iron accumulation in BfrB and cytosolic iron deprivation. Consequently,
given the intracellular iron sufficiency requirement for biofilm development,
we hypothesized that blocking the BfrB-Bfd interaction in P. aeruginosa would impair biofilm development. Our results
show that planktonic and biofilm-embedded cells where the BfrB-Bfd
complex is blocked exhibit cytosolic iron deficiency, and poorly developed
biofilms, even in iron-sufficient culture conditions. These results
underscore inhibition of the BfrB-Bfd complex as a rational target
to dysregulate iron homeostasis and possibly control biofilms.
Collapse
Affiliation(s)
- Anabel Soldano
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
| | - Huili Yao
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
| | - Josephine R. Chandler
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, Kansas 66045, United States
| | - Mario Rivera
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
| |
Collapse
|
14
|
Bardin EE, Cameron SJS, Perdones-Montero A, Hardiman K, Bolt F, Alton EWFW, Bush A, Davies JC, Takáts Z. Metabolic Phenotyping and Strain Characterisation of Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients Using Rapid Evaporative Ionisation Mass Spectrometry. Sci Rep 2018; 8:10952. [PMID: 30026575 PMCID: PMC6053451 DOI: 10.1038/s41598-018-28665-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 06/22/2018] [Indexed: 01/16/2023] Open
Abstract
Rapid evaporative ionisation mass spectrometry (REIMS) is a novel technique for the real-time analysis of biological material. It works by conducting an electrical current through a sample, causing it to rapidly heat and evaporate, with the analyte containing vapour channelled to a mass spectrometer. It was used to characterise the metabolome of 45 Pseudomonas aeruginosa (P. aeruginosa) isolates from cystic fibrosis (CF) patients and compared to 80 non-CF P. aeruginosa. Phospholipids gave the highest signal intensity; 17 rhamnolipids and 18 quorum sensing molecules were detected, demonstrating that REIMS has potential for the study of virulence-related metabolites. P. aeruginosa isolates obtained from respiratory samples showed a higher diversity, which was attributed to the chronic nature of most respiratory infections. The analytical sensitivity of REIMS allowed the detection of a metabolome that could be used to classify individual P. aeruginosa isolates after repeated culturing with 81% accuracy, and an average 83% concordance with multilocus sequence typing. This study underpins the capacities of REIMS as a tool with clinical applications, such as metabolic phenotyping of the important CF pathogen P. aeruginosa, and highlights the potential of metabolic fingerprinting for fine scale characterisation at a sub-species level.
Collapse
Affiliation(s)
- Emmanuelle E Bardin
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Simon J S Cameron
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | | | - Kate Hardiman
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Frances Bolt
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Eric W F W Alton
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Andrew Bush
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.,Department of Paediatric Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
| | - Jane C Davies
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.,Department of Paediatric Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
| | - Zoltan Takáts
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
| |
Collapse
|
15
|
Freund JR, Mansfield CJ, Doghramji LJ, Adappa ND, Palmer JN, Kennedy DW, Reed DR, Jiang P, Lee RJ. Activation of airway epithelial bitter taste receptors by Pseudomonas aeruginosa quinolones modulates calcium, cyclic-AMP, and nitric oxide signaling. J Biol Chem 2018; 293:9824-9840. [PMID: 29748385 DOI: 10.1074/jbc.ra117.001005] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 04/17/2018] [Indexed: 12/12/2022] Open
Abstract
Bitter taste receptors (taste family 2 bitter receptor proteins; T2Rs), discovered in many tissues outside the tongue, have recently become potential therapeutic targets. We have shown previously that airway epithelial cells express several T2Rs that activate innate immune responses that may be important for treatment of airway diseases such as chronic rhinosinusitis. It is imperative to more clearly understand what compounds activate airway T2Rs as well as their full range of functions. T2R isoforms in airway motile cilia (T2R4, -14, -16, and -38) produce bactericidal levels of nitric oxide (NO) that also increase ciliary beating, promoting clearance of mucus and trapped pathogens. Bacterial quorum-sensing acyl-homoserine lactones activate T2Rs and stimulate these responses in primary airway cells. Quinolones are another type of quorum-sensing molecule used by Pseudomonas aeruginosa To elucidate whether bacterial quinolones activate airway T2Rs, we analyzed calcium, cAMP, and NO dynamics using a combination of fluorescent indicator dyes and FRET-based protein biosensors. T2R-transfected HEK293T cells, several lung epithelial cell lines, and primary sinonasal cells grown and differentiated at the air-liquid interface were tested with 2-heptyl-3-hydroxy-4-quinolone (known as Pseudomonas quinolone signal; PQS), 2,4-dihydroxyquinolone, and 4-hydroxy-2-heptylquinolone (HHQ). In HEK293T cells, PQS activated T2R4, -16, and -38, whereas HHQ activated T2R14. 2,4-Dihydroxyquinolone had no effect. PQS and HHQ increased calcium and decreased both baseline and stimulated cAMP levels in cultured and primary airway cells. In primary cells, PQS and HHQ activated levels of NO synthesis previously shown to be bactericidal. This study suggests that airway T2R-mediated immune responses are activated by bacterial quinolones as well as acyl-homoserine lactones.
Collapse
Affiliation(s)
- Jenna R Freund
- From the Departments of Otorhinolaryngology-Head and Neck Surgery and
| | | | | | - Nithin D Adappa
- From the Departments of Otorhinolaryngology-Head and Neck Surgery and
| | - James N Palmer
- From the Departments of Otorhinolaryngology-Head and Neck Surgery and
| | - David W Kennedy
- From the Departments of Otorhinolaryngology-Head and Neck Surgery and
| | - Danielle R Reed
- the Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104
| | - Peihua Jiang
- the Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104
| | - Robert J Lee
- From the Departments of Otorhinolaryngology-Head and Neck Surgery and .,Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104 and
| |
Collapse
|
16
|
Dunham SJB, Ellis JF, Baig NF, Morales-Soto N, Cao T, Shrout JD, Bohn PW, Sweedler JV. Quantitative SIMS Imaging of Agar-Based Microbial Communities. Anal Chem 2018; 90:5654-5663. [PMID: 29623707 PMCID: PMC5930052 DOI: 10.1021/acs.analchem.7b05180] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
After several decades of widespread use for mapping elemental ions and small molecular fragments in surface science, secondary ion mass spectrometry (SIMS) has emerged as a powerful analytical tool for molecular imaging in biology. Biomolecular SIMS imaging has primarily been used as a qualitative technique; although the distribution of a single analyte can be accurately determined, it is difficult to map the absolute quantity of a compound or even to compare the relative abundance of one molecular species to that of another. We describe a method for quantitative SIMS imaging of small molecules in agar-based microbial communities. The microbes are cultivated on a thin film of agar, dried under nitrogen, and imaged directly with SIMS. By use of optical microscopy, we show that the area of the agar is reduced by 26 ± 2% (standard deviation) during dehydration, but the overall biofilm morphology and analyte distribution are largely retained. We detail a quantitative imaging methodology, in which the ion intensity of each analyte is (1) normalized to an external quadratic regression curve, (2) corrected for isomeric interference, and (3) filtered for sample-specific noise and lower and upper limits of quantitation. The end result is a two-dimensional surface density image for each analyte. The sample preparation and quantitation methods are validated by quantitatively imaging four alkyl-quinolone and alkyl-quinoline N-oxide signaling molecules (including Pseudomonas quinolone signal) in Pseudomonas aeruginosa colony biofilms. We show that the relative surface densities of the target biomolecules are substantially different from values inferred through direct intensity comparison and that the developed methodologies can be used to quantitatively compare as many ions as there are available standards.
Collapse
Affiliation(s)
- Sage J. B. Dunham
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana- Champaign, Urbana, IL 61801
| | - Joseph F. Ellis
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana- Champaign, Urbana, IL 61801
| | - Nameera F. Baig
- Department of Chemistry and Biochemistry, and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Nydia Morales-Soto
- Department of Civil and Environmental Engineering and Earth Sciences, and Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - Tianyuan Cao
- Department of Chemistry and Biochemistry, and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Joshua D. Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, and Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - Paul W. Bohn
- Department of Chemistry and Biochemistry, and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Jonathan V. Sweedler
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana- Champaign, Urbana, IL 61801
| |
Collapse
|
17
|
Morales-Soto N, Dunham SJB, Baig NF, Ellis JF, Madukoma CS, Bohn PW, Sweedler JV, Shrout JD. Spatially dependent alkyl quinolone signaling responses to antibiotics in Pseudomonas aeruginosa swarms. J Biol Chem 2018; 293:9544-9552. [PMID: 29588364 DOI: 10.1074/jbc.ra118.002605] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/22/2018] [Indexed: 11/06/2022] Open
Abstract
There is a general lack of understanding about how communities of bacteria respond to exogenous toxins such as antibiotics. Most of our understanding of community-level stress responses comes from the study of stationary biofilm communities. Although several community behaviors and production of specific biomolecules affecting biofilm development and associated behavior have been described for Pseudomonas aeruginosa and other bacteria, we have little appreciation for the production and dispersal of secreted metabolites within the 2D and 3D spaces they occupy as they colonize, spread, and grow on surfaces. Here we specifically studied the phenotypic responses and spatial variability of alkyl quinolones, including the Pseudomonas quinolone signal (PQS) and members of the alkyl hydroxyquinoline (AQNO) subclass, in P. aeruginosa plate-assay swarming communities. We found that PQS production was not a universal signaling response to antibiotics, as tobramycin elicited an alkyl quinolone response, whereas carbenicillin did not. We also found that PQS and AQNO profiles in response to tobramycin were markedly distinct and influenced these swarms on different spatial scales. At some tobramycin exposures, P. aeruginosa swarms produced alkyl quinolones in the range of 150 μm PQS and 400 μm AQNO that accumulated as aggregates. Our collective findings show that the distribution of alkyl quinolones can vary by several orders of magnitude within the same swarming community. More notably, our results suggest that multiple intercellular signals acting on different spatial scales can be triggered by one common cue.
Collapse
Affiliation(s)
- Nydia Morales-Soto
- From the Departments of Civil and Environmental Engineering and Earth Sciences
| | - Sage J B Dunham
- the Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | | | - Joseph F Ellis
- the Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Chinedu S Madukoma
- From the Departments of Civil and Environmental Engineering and Earth Sciences
| | - Paul W Bohn
- Chemistry and Biochemistry.,Chemical and Biomolecular Engineering, and
| | - Jonathan V Sweedler
- the Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Joshua D Shrout
- From the Departments of Civil and Environmental Engineering and Earth Sciences, .,Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556 and
| |
Collapse
|
18
|
Ó Muimhneacháin E, Reen FJ, O'Gara F, McGlacken GP. Analogues ofPseudomonas aeruginosasignalling molecules to tackle infections. Org Biomol Chem 2018; 16:169-179. [DOI: 10.1039/c7ob02395b] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The emergence of antibiotic resistance coupled with the lack of investment by pharmaceutical companies necessitates a new look at how we tackle bacterial infections.
Collapse
Affiliation(s)
- Eoin Ó Muimhneacháin
- School of Chemistry and Analytical and Biological Chemistry Research Facility
- University College Cork
- College Road
- Cork
- Ireland
| | - F. Jerry Reen
- School of Microbiology
- University College Cork
- Ireland
- BIOMERIT Research Centre
- School of Microbiology
| | - Fergal O'Gara
- BIOMERIT Research Centre
- School of Microbiology
- University College Cork
- Ireland
- School of Biomedical Sciences
| | - Gerard P. McGlacken
- School of Chemistry and Analytical and Biological Chemistry Research Facility
- University College Cork
- College Road
- Cork
- Ireland
| |
Collapse
|
19
|
Yang J, Toyofuku M, Sakai R, Nomura N. Influence of the alginate production on cell-to-cell communication in Pseudomonas aeruginosa PAO1. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:239-249. [PMID: 28120378 DOI: 10.1111/1758-2229.12521] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/13/2017] [Accepted: 01/18/2017] [Indexed: 06/06/2023]
Abstract
Many bacteria communicate with each other through signalling molecules, a process known as cell-to-cell communication. During this process, it is important for the signalling molecules to: (1) reach the target cells; and (2) to be received by the cognate receptor. Barriers such as the presence of extracellular matrix may prevent signals from reaching their targets; however, the influence of the extracellular matrix on cell-to-cell communication has scarcely been studied. Here, we demonstrate that the overproduction of an extracellular matrix, alginate, in a Pseudomonas aeruginosa mucoid variant, alters cell-to-cell communication by interfering with the response to quinolone signals while having no effect on N-acyl-L-homoserine lactones. The inhibition of quinolone signalling by alginate is limited to the alginate overproducer and has no effect on neighbour cells that do not produce alginate. Our study indicates that alginate overproduction affects the cell-to-cell communication of the mucoid variant, which may results in different downstream behaviours when it emerges in the presence of the wild-type (WT).
Collapse
Affiliation(s)
- Jiayue Yang
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Masanori Toyofuku
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
- Department of Plant and Microbial Biology, University of Zurich, Zürich, 8008, Switzerland
| | - Ryosuke Sakai
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Nobuhiko Nomura
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| |
Collapse
|
20
|
Limoli DH, Whitfield GB, Kitao T, Ivey ML, Davis MR, Grahl N, Hogan DA, Rahme LG, Howell PL, O'Toole GA, Goldberg JB. Pseudomonas aeruginosa Alginate Overproduction Promotes Coexistence with Staphylococcus aureus in a Model of Cystic Fibrosis Respiratory Infection. mBio 2017; 8:e00186-17. [PMID: 28325763 PMCID: PMC5362032 DOI: 10.1128/mbio.00186-17] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 02/22/2017] [Indexed: 01/30/2023] Open
Abstract
While complex intra- and interspecies microbial community dynamics are apparent during chronic infections and likely alter patient health outcomes, our understanding of these interactions is currently limited. For example, Pseudomonas aeruginosa and Staphylococcus aureus are often found to coinfect the lungs of patients with cystic fibrosis (CF), yet these organisms compete under laboratory conditions. Recent observations that coinfection correlates with decreased health outcomes necessitate we develop a greater understanding of these interbacterial interactions. In this study, we tested the hypothesis that P. aeruginosa and/or S. aureus adopts phenotypes that allow coexistence during infection. We compared competitive interactions of P. aeruginosa and S. aureus isolates from mono- or coinfected CF patients employing in vitro coculture models. P. aeruginosa isolates from monoinfected patients were more competitive toward S. aureus than P. aeruginosa isolates from coinfected patients. We also observed that the least competitive P. aeruginosa isolates possessed a mucoid phenotype. Mucoidy occurs upon constitutive activation of the sigma factor AlgT/U, which regulates synthesis of the polysaccharide alginate and dozens of other secreted factors, including some previously described to kill S. aureus Here, we show that production of alginate in mucoid strains is sufficient to inhibit anti-S. aureus activity independent of activation of the AlgT regulon. Alginate reduces production of siderophores, 2-heptyl-4-hydroxyquinolone-N-oxide (HQNO), and rhamnolipids-each required for efficient killing of S. aureus These studies demonstrate alginate overproduction may be an important factor driving P. aeruginosa coinfection with S. aureusIMPORTANCE Numerous deep-sequencing studies have revealed the microbial communities present during respiratory infections in cystic fibrosis (CF) patients are diverse, complex, and dynamic. We now face the challenge of determining the influence of these community dynamics on patient health outcomes and identifying candidate targets to modulate these interactions. We make progress toward this goal by determining that the polysaccharide alginate produced by mucoid strains of P. aeruginosa is sufficient to inhibit multiple secreted antimicrobial agents produced by this organism. Importantly, these secreted factors are required to outcompete S. aureus, when the microbes are grown in coculture; thus we propose a mechanism whereby mucoid P. aeruginosa can coexist with S. aureus Finally, the approach used here can serve as a platform to investigate the interactions among other CF pathogens.
Collapse
Affiliation(s)
- Dominique H Limoli
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Tomoe Kitao
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
| | - Melissa L Ivey
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Michael R Davis
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Nora Grahl
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Deborah A Hogan
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Laurence G Rahme
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
| | - P Lynne Howell
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - George A O'Toole
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
21
|
Harvey EL, Deering RW, Rowley DC, El Gamal A, Schorn M, Moore BS, Johnson MD, Mincer TJ, Whalen KE. A Bacterial Quorum-Sensing Precursor Induces Mortality in the Marine Coccolithophore, Emiliania huxleyi. Front Microbiol 2016; 7:59. [PMID: 26870019 PMCID: PMC4737879 DOI: 10.3389/fmicb.2016.00059] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/13/2016] [Indexed: 11/29/2022] Open
Abstract
Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here, we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. HHQ functions as both an antibiotic and a bacterial signaling molecule in cell–cell communication in clinical infection models. Co-culture of the bloom-forming coccolithophore, Emiliania huxleyi with both live P. piscicida and cell-free filtrates caused a significant decrease in algal growth. Investigations of the P. piscicida exometabolome revealed HHQ, at nanomolar concentrations, induced mortality in three strains of E. huxleyi. Mortality of E. huxleyi in response to HHQ occurred slowly, implying static growth rather than a singular loss event (e.g., rapid cell lysis). In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures. These results suggest that HHQ mediates the type of inter-domain interactions that cause shifts in phytoplankton population dynamics. These chemically mediated interactions, and other like it, ultimately influence large-scale oceanographic processes.
Collapse
Affiliation(s)
- Elizabeth L Harvey
- Department of Marine Sciences, Skidaway Institute of Oceanography, University of Georgia, Savannah GA, USA
| | - Robert W Deering
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston RI, USA
| | - David C Rowley
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston RI, USA
| | - Abrahim El Gamal
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla CA, USA
| | - Michelle Schorn
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla CA, USA
| | - Bradley S Moore
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla CA, USA
| | - Matthew D Johnson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole MA, USA
| | - Tracy J Mincer
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole MA, USA
| | - Kristen E Whalen
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole MA, USA
| |
Collapse
|
22
|
Lovaglio R, Silva V, Ferreira H, Hausmann R, Contiero J. Rhamnolipids know-how: Looking for strategies for its industrial dissemination. Biotechnol Adv 2015; 33:1715-26. [DOI: 10.1016/j.biotechadv.2015.09.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 09/02/2015] [Accepted: 09/06/2015] [Indexed: 11/29/2022]
|
23
|
Rhodococcus erythropolis BG43 Genes Mediating Pseudomonas aeruginosa Quinolone Signal Degradation and Virulence Factor Attenuation. Appl Environ Microbiol 2015; 81:7720-9. [PMID: 26319870 DOI: 10.1128/aem.02145-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/22/2015] [Indexed: 01/25/2023] Open
Abstract
Rhodococcus erythropolis BG43 is able to degrade the Pseudomonas aeruginosa quorum sensing signal molecules PQS (Pseudomonas quinolone signal) [2-heptyl-3-hydroxy-4(1H)-quinolone] and HHQ [2-heptyl-4(1H)-quinolone] to anthranilic acid. Based on the hypothesis that degradation of HHQ might involve hydroxylation to PQS followed by dioxygenolytic cleavage of the heterocyclic ring and hydrolysis of the resulting N-octanoylanthranilate, the genome was searched for corresponding candidate genes. Two gene clusters, aqdA1B1C1 and aqdA2B2C2, each predicted to code for a hydrolase, a flavin monooxygenase, and a dioxygenase related to 1H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase, were identified on circular plasmid pRLCBG43 of strain BG43. Transcription of all genes was upregulated by PQS, suggesting that both gene clusters code for alkylquinolone-specific catabolic enzymes. An aqdR gene encoding a putative transcriptional regulator, which was also inducible by PQS, is located adjacent to the aqdA2B2C2 cluster. Expression of aqdA2B2C2 in Escherichia coli conferred the ability to degrade HHQ and PQS to anthranilic acid; however, for E. coli transformed with aqdA1B1C1, only PQS degradation was observed. Purification of the recombinant AqdC1 protein verified that it catalyzes the cleavage of PQS to form N-octanoylanthranilic acid and carbon monoxide and revealed apparent Km and kcat values for PQS of ∼27 μM and 21 s(-1), respectively. Heterologous expression of the PQS dioxygenase gene aqdC1 or aqdC2 in P. aeruginosa PAO1 quenched the production of the virulence factors pyocyanin and rhamnolipid and reduced the synthesis of the siderophore pyoverdine. Thus, the toolbox of quorum-quenching enzymes is expanded by new PQS dioxygenases.
Collapse
|
24
|
Sams T, Baker Y, Hodgkinson J, Gross J, Spring D, Welch M. The Pseudomonas Quinolone Signal (PQS). Isr J Chem 2015. [DOI: 10.1002/ijch.201400128] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
25
|
Soh EYC, Chhabra SR, Halliday N, Heeb S, Müller C, Birmes FS, Fetzner S, Cámara M, Chan KG, Williams P. Biotic inactivation of the Pseudomonas aeruginosa quinolone signal molecule. Environ Microbiol 2015; 17:4352-65. [PMID: 25809238 DOI: 10.1111/1462-2920.12857] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/06/2015] [Accepted: 03/06/2015] [Indexed: 11/29/2022]
Abstract
In Pseudomonas aeruginosa, quorum sensing (QS) regulates the production of secondary metabolites, many of which are antimicrobials that impact on polymicrobial community composition. Consequently, quenching QS modulates the environmental impact of P. aeruginosa. To identify bacteria capable of inactivating the QS signal molecule 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), a minimal medium containing PQS as the sole carbon source was used to enrich a Malaysian rainforest soil sample. This yielded an Achromobacter xylosoxidans strain (Q19) that inactivated PQS, yielding a new fluorescent compound (I-PQS) confirmed as PQS-derived using deuterated PQS. The I-PQS structure was elucidated using mass spectrometry and nuclear magnetic resonance spectroscopy as 2-heptyl-2-hydroxy-1,2-dihydroquinoline-3,4-dione (HHQD). Achromobacter xylosoxidans Q19 oxidized PQS congeners with alkyl chains ranging from C1 to C5 and also N-methyl PQS, yielding the corresponding 2-hydroxy-1,2-dihydroquinoline-3,4-diones, but was unable to inactivate the PQS precursor HHQ. This indicates that the hydroxyl group at position 3 in PQS is essential and that A. xylosoxidans inactivates PQS via a pathway involving the incorporation of oxygen at C2 of the heterocyclic ring. The conversion of PQS to HHQD also occurred on incubation with 12/17 A. xylosoxidans strains recovered from cystic fibrosis patients, with P. aeruginosa and with Arthrobacter, suggesting that formation of hydroxylated PQS may be a common mechanism of inactivation.
Collapse
Affiliation(s)
- Eliza Ye-Chen Soh
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.,Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Siri R Chhabra
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Nigel Halliday
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Stephan Heeb
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Christine Müller
- Institute of Molecular Microbiology and Biotechnology, University of Muenster, D-48149, Muenster, Germany
| | - Franziska S Birmes
- Institute of Molecular Microbiology and Biotechnology, University of Muenster, D-48149, Muenster, Germany
| | - Susanne Fetzner
- Institute of Molecular Microbiology and Biotechnology, University of Muenster, D-48149, Muenster, Germany
| | - Miguel Cámara
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Paul Williams
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| |
Collapse
|
26
|
Pezzoni M, Meichtry M, Pizarro RA, Costa CS. Role of the Pseudomonas quinolone signal (PQS) in sensitising Pseudomonas aeruginosa to UVA radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 142:129-40. [DOI: 10.1016/j.jphotobiol.2014.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/20/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
|
27
|
Lanni EJ, Masyuko R, Driscoll CM, Aerts JT, Shrout JD, Bohn PW, Sweedler JV. MALDI-guided SIMS: multiscale imaging of metabolites in bacterial biofilms. Anal Chem 2014; 86:9139-45. [PMID: 25133532 PMCID: PMC4165220 DOI: 10.1021/ac5020222] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 08/18/2014] [Indexed: 12/21/2022]
Abstract
Mass spectrometry imaging (MSI) is a versatile tool for visualizing molecular distributions in complex biological specimens, but locating microscopic chemical features of interest can be challenging in samples that lack a well-defined anatomy. To address this issue, we developed a correlated imaging approach that begins with performing matrix-assisted laser desorption/ionization (MALDI) MSI to obtain low-resolution molecular maps of a sample. The resulting maps are then used to direct subsequent microscopic secondary ion mass spectrometry (SIMS) imaging and tandem mass spectrometry (MS/MS) experiments to examine selected chemical regions of interest. By employing MALDI undersampling, the sample surface is left mostly unperturbed and available for the SIMS analysis, while also generating an ablation array that can be used for navigation in SIMS. We validated this MALDI-guided SIMS approach using cultured biofilms of the opportunistic pathogen Pseudomonas aeruginosa; bioactive secondary metabolites, including rhamnolipids and quinolones, were detected and visualized on both macro- and microscopic size scales. MSI mass assignments were confirmed with in situ MALDI MS/MS and capillary electrophoresis-electrospray ionization MS/MS analysis of biofilm extracts. Two strains of P. aeruginosa were compared, wild type and a quorum sensing mutant, and differences in metabolite abundance and distribution were observed.
Collapse
Affiliation(s)
- Eric J. Lanni
- Department
of Chemistry and Beckman Institute for Advanced Science
and Technology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Rachel
N. Masyuko
- Department of Chemistry and Biochemistry and Department
of Chemical
and Biomolecular Engineering, and Department of Civil and Environmental Engineering
and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Callan M. Driscoll
- Department of Chemistry and Biochemistry and Department
of Chemical
and Biomolecular Engineering, and Department of Civil and Environmental Engineering
and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jordan T. Aerts
- Department
of Chemistry and Beckman Institute for Advanced Science
and Technology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Joshua D. Shrout
- Department of Chemistry and Biochemistry and Department
of Chemical
and Biomolecular Engineering, and Department of Civil and Environmental Engineering
and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Paul W. Bohn
- Department of Chemistry and Biochemistry and Department
of Chemical
and Biomolecular Engineering, and Department of Civil and Environmental Engineering
and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jonathan V. Sweedler
- Department
of Chemistry and Beckman Institute for Advanced Science
and Technology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
28
|
Biggins JB, Kang HS, Ternei MA, DeShazer D, Brady SF. The chemical arsenal of Burkholderia pseudomallei is essential for pathogenicity. J Am Chem Soc 2014; 136:9484-90. [PMID: 24884988 PMCID: PMC4091270 DOI: 10.1021/ja504617n] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Increasing evidence has shown that
small-molecule chemistry in
microbes (i.e., secondary metabolism) can modulate the microbe–host
response in infection and pathogenicity. The bacterial disease melioidosis
is conferred by the highly virulent, antibiotic-resistant pathogen Burkholderia pseudomallei (BP). Whereas
some macromolecular structures have been shown to influence BP virulence (e.g., secretion systems, cellular capsule,
pili), the role of the large cryptic secondary metabolome encoded
within its genome has been largely unexplored for its importance to
virulence. Herein we demonstrate that BP-encoded
small-molecule biosynthesis is indispensible for in vivo BP pathogenicity. Promoter exchange experiments were used to induce
high-level molecule production from two gene clusters (MPN and SYR)
found to be essential for in vivo virulence. NMR
structural characterization of these metabolites identified a new
class of lipopeptide biosurfactants/biofilm modulators (the
malleipeptins) and syrbactin-type proteasome inhibitors, both
of which represent overlooked small-molecule virulence factors for BP. Disruption of Burkholderia virulence by inhibiting the
biosynthesis of these small-molecule biosynthetic pathways may prove
to be an effective strategy for developing novel melioidosis-specific
therapeutics.
Collapse
Affiliation(s)
- John B Biggins
- Laboratory of Genetically Encoded Small Molecules, Howard Hughes Medical Institute , The Rockefeller University , 1230 York Avenue, New York, New York 10065, United States
| | | | | | | | | |
Collapse
|
29
|
Singh AK, Cameotra SS. Influence of microbial and synthetic surfactant on the biodegradation of atrazine. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:2088-2097. [PMID: 24026208 DOI: 10.1007/s11356-013-2127-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/30/2013] [Indexed: 05/26/2023]
Abstract
The present study reports the effect of surfactants (rhamnolipids and triton X-100) on biodegradation of atrazine herbicide by strain A6, belonging to the genus Acinetobacter. The strain A6 was able to degrade nearly 80 % of the 250-ppm atrazine after 6 days of growth. The bacterium degraded atrazine by de-alkylation process. Bacterial cell surface hydrophobicity as well as atrazine solubility increased in the presence of surfactant. However, addition of surfactant to the mineral salt media reduced the rate and extent of atrazine degradation by decreasing the bioavailability of herbicide. On the contrary, addition of surfactant to atrazine-contaminated soil increased the rate and extent of biodegradation by increasing the bioavailability of herbicide. As compared to triton X-100, rhamnolipids were more efficient in enhancing microbial degradation of atrazine as a significant amount of atrazine was removed from the soil by rhamnolipids. Surfactants added for the purpose of hastening microbial degradation may have an unintended inhibitory effect on herbicide degradation depending upon contiguous condition, thus highlighting the fact that surfactant must be judiciously used in bioremediation of herbicides.
Collapse
Affiliation(s)
- Anil Kumar Singh
- Institute of Microbial Technology, Sector 39 A, Chandigarh, 160036, India
| | | |
Collapse
|
30
|
Rhamnolipid production: effect of oxidative stress on virulence factors and proteome of Pseudomonas aeruginosa PA1. Appl Microbiol Biotechnol 2012; 95:1519-29. [DOI: 10.1007/s00253-012-4258-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
|
31
|
Ha DG, Merritt JH, Hampton TH, Hodgkinson JT, Janecek M, Spring DR, Welch M, O'Toole GA. 2-Heptyl-4-quinolone, a precursor of the Pseudomonas quinolone signal molecule, modulates swarming motility in Pseudomonas aeruginosa. J Bacteriol 2011; 193:6770-80. [PMID: 21965567 PMCID: PMC3232867 DOI: 10.1128/jb.05929-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 09/20/2011] [Indexed: 01/13/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen capable of group behaviors, including biofilm formation and swarming motility. These group behaviors are regulated by both the intracellular signaling molecule c-di-GMP and acylhomoserine lactone quorum-sensing systems. Here, we show that the Pseudomonas quinolone signal (PQS) system also contributes to the regulation of swarming motility. Specifically, our data indicate that 2-heptyl-4-quinolone (HHQ), a precursor of PQS, likely induces the production of the phenazine-1-carboxylic acid (PCA), which in turn acts via an as-yet-unknown downstream mechanism to repress swarming motility. We show that this HHQ- and PCA-dependent swarming repression is apparently independent of changes in global levels of c-di-GMP, suggesting complex regulation of this group behavior.
Collapse
Affiliation(s)
- Dae-Gon Ha
- Dartmouth Medical School, Department of Microbiology and Immunology, Hanover, New Hampshire 03755
| | - Judith H. Merritt
- Dartmouth Medical School, Department of Microbiology and Immunology, Hanover, New Hampshire 03755
| | - Thomas H. Hampton
- Dartmouth Medical School, Department of Microbiology and Immunology, Hanover, New Hampshire 03755
| | - James T. Hodgkinson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom
| | - Matej Janecek
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - David R. Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom
| | - George A. O'Toole
- Dartmouth Medical School, Department of Microbiology and Immunology, Hanover, New Hampshire 03755
| |
Collapse
|
32
|
The surfactant of Legionella pneumophila Is secreted in a TolC-dependent manner and is antagonistic toward other Legionella species. J Bacteriol 2011; 193:5971-84. [PMID: 21890700 DOI: 10.1128/jb.05405-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When Legionella pneumophila grows on agar plates, it secretes a surfactant that promotes flagellum- and pilus-independent "sliding" motility. We isolated three mutants that were defective for surfactant. The first two had mutations in genes predicted to encode cytoplasmic enzymes involved in lipid metabolism. These genes mapped to two adjacent operons that we designated bbcABCDEF and bbcGHIJK. Backcrossing and complementation confirmed the importance of the bbc genes and suggested that the Legionella surfactant is lipid containing. The third mutant had an insertion in tolC. TolC is the outer membrane part of various trimolecular complexes involved in multidrug efflux and type I protein secretion. Complementation of the tolC mutant restored sliding motility. Mutants defective for an inner membrane partner of TolC also lacked a surfactant, confirming that TolC promotes surfactant secretion. L. pneumophila (lspF) mutants lacking type II protein secretion (T2S) are also impaired for a surfactant. When the tolC and lspF mutants were grown next to each other, the lsp mutant secreted surfactant, suggesting that TolC and T2S conjoin to mediate surfactant secretion, with one being the conduit for surfactant export and the other the exporter of a molecule that is required for induction or maturation of surfactant synthesis/secretion. Although the surfactant was not required for the extracellular growth, intracellular infection, and intrapulmonary survival of L. pneumophila, it exhibited antimicrobial activity toward seven other species of Legionella but not toward various non-Legionella species. These data suggest that the surfactant provides L. pneumophila with a selective advantage over other legionellae in the natural environment.
Collapse
|
33
|
Toyofuku M, Nakajima-Kambe T, Uchiyama H, Nomura N. The effect of a cell-to-cell communication molecule, Pseudomonas quinolone signal (PQS), produced by P. aeruginosa on other bacterial species. Microbes Environ 2011; 25:1-7. [PMID: 21576845 DOI: 10.1264/jsme2.me09156] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
One of the most important factors in the development of a bacterial community is whether the bacteria are able to grow in that habitat. The regulation of bacterial growth is generally studied in relation to physicochemical conditions, however, how bacterial communities regulate themselves remains unclear. In our previous study, it was demonstrated that a cell-to-cell communication molecule, 2-heptyl-3-hydroxy-4-quinolone, referred to as the Pseudomonas quinolone signal (PQS), affects respiring-activity in Pseudomonas aeruginosa without requiring its cognate receptor PqsR. The results suggested that PQS may affect other bacterial species, which was further examined in this study. PQS repressed the growth of several species including both Gram-negative and Gram-positive bacteria. In most cases, this effect differed from the bacteriostatic or bacteriolytic actions of antibiotics. The growth repression by PQS was inhibited when iron was added to the medium, indicating iron-chelating activity to be involved. In addition, PQS affected oxygen consumption in some species tested, and may have other underlying effects. Thus, this cell-to-cell communication molecule may influence the development of bacterial communities by regulating bacterial growth, and physicochemical factors such as iron would be important in determining its effect.
Collapse
Affiliation(s)
- Masanori Toyofuku
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennoudai 1–1–1, Tsukuba, Ibaraki, Japan
| | | | | | | |
Collapse
|
34
|
Croda-García G, Grosso-Becerra V, Gonzalez-Valdez A, Servín-González L, Soberón-Chávez G. Transcriptional regulation of Pseudomonas aeruginosa rhlR: role of the CRP orthologue Vfr (virulence factor regulator) and quorum-sensing regulators LasR and RhlR. MICROBIOLOGY-SGM 2011; 157:2545-2555. [PMID: 21719541 DOI: 10.1099/mic.0.050161-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The production of many virulence factors by Pseudomonas aeruginosa is regulated by the quorum-sensing (QS) response. In this regulatory network LasR and RhlR, bound to their corresponding autoinducers, play a central role. The QS response has a hierarchical structure: LasR/3O-C12-HSL activates the transcription of rhlR, and RhlR/C4-HSL activates the transcription of several genes, including the rhlAB operon, which encodes the enzymes responsible for rhamnolipid synthesis. The rhlAB operon is located immediately upstream of the rhlR gene. rhlR has four transcription start sites, two of which are located in the rhlB coding region. Vfr directly activates transcription of lasR, and has been reported to be also involved in rhlR expression. The aim of this work was to characterize the details of the mechanism of rhlR transcriptional regulation. We show that Vfr directly regulates rhlR transcription through its binding to several Vfr-binding sites (VBSs) present in the rhlR promoter region, one of which has a negative effect on transcription. Two of the VBSs overlap with las boxes where LasR/3O-C12-HSL binds to activate rhlR transcription. We also show that rhlR transcription is subject to positive-feedback autoregulation through RhlR/C4-HSL activation of the rhlA promoter. This positive autoregulation plays a major role in rhlR expression.
Collapse
Affiliation(s)
- Gerardo Croda-García
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo Postal 70228, México DF 04510, Mexico
| | - Victoria Grosso-Becerra
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo Postal 70228, México DF 04510, Mexico
| | - Abigail Gonzalez-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo Postal 70228, México DF 04510, Mexico
| | - Luis Servín-González
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo Postal 70228, México DF 04510, Mexico
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apdo Postal 70228, México DF 04510, Mexico
| |
Collapse
|
35
|
Reis RS, Pereira AG, Neves BC, Freire DMG. Gene regulation of rhamnolipid production in Pseudomonas aeruginosa--a review. BIORESOURCE TECHNOLOGY 2011; 102:6377-84. [PMID: 21498076 DOI: 10.1016/j.biortech.2011.03.074] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 03/22/2011] [Accepted: 03/23/2011] [Indexed: 05/09/2023]
Abstract
Pseudomonas aeruginosa produces abundant levels of rhamnolipid biosurfactants which exhibit remarkable chemical and physical characteristics, making these compounds attractive targets for biotechnology research. The complex gene regulation network involved in rhamnolipids' biosynthesis represents a challenge to industrial production, which has been the object of a growing number of studies. This article provides a comprehensive review of the known gene regulatory factors involved in rhamnolipid production within P. aeruginosa. The regulatory factors include quorum sensing systems proteins and environmental response, and global regulatory systems within basal bacterial physiology, acting either at transcriptional or post-transcriptional level. The multilayer gene regulation responds to a wide variety of environmental and physiologic signals, and is capable of combining different signals in unique and specific responses.
Collapse
Affiliation(s)
- Rodrigo S Reis
- University of Sydney, School of Molecular Biology, NSW 2006, Australia.
| | | | | | | |
Collapse
|
36
|
Reen FJ, Mooij MJ, Holcombe LJ, McSweeney CM, McGlacken GP, Morrissey JP, O'Gara F. The Pseudomonas quinolone signal (PQS), and its precursor HHQ, modulate interspecies and interkingdom behaviour. FEMS Microbiol Ecol 2011; 77:413-28. [PMID: 21539583 DOI: 10.1111/j.1574-6941.2011.01121.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Pseudomonas quinolone signal (PQS), and its precursor 2-heptyl-4-quinolone (HHQ), play a key role in coordinating virulence in the important cystic fibrosis pathogen Pseudomonas aeruginosa. The discovery of HHQ analogues in Burkholderia and other microorganisms led us to investigate the possibility that these compounds can influence interspecies behaviour. We found that surface-associated phenotypes were repressed in Gram-positive and Gram-negative bacteria as well as in pathogenic yeast in response to PQS and HHQ. Motility was repressed in a broad range of bacteria, while biofilm formation in Bacillus subtilis and Candida albicans was repressed in the presence of HHQ, though initial adhesion was unaffected. Furthermore, HHQ exhibited potent bacteriostatic activity against several Gram-negative bacteria, including pathogenic Vibrio vulnificus. Structure-function analysis using synthetic analogues provided an insight into the molecular properties that underpin the ability of these compounds to influence microbial behaviour, revealing the alkyl chain to be fundamental. Defining the influence of these molecules on microbial-eukaryotic-host interactions will facilitate future therapeutic strategies which seek to combat microorganisms that are recalcitrant to conventional antimicrobial agents.
Collapse
Affiliation(s)
- F Jerry Reen
- BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland
| | | | | | | | | | | | | |
Collapse
|
37
|
Heeb S, Fletcher MP, Chhabra SR, Diggle SP, Williams P, Cámara M. Quinolones: from antibiotics to autoinducers. FEMS Microbiol Rev 2011; 35:247-74. [PMID: 20738404 PMCID: PMC3053476 DOI: 10.1111/j.1574-6976.2010.00247.x] [Citation(s) in RCA: 386] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Since quinine was first isolated, animals, plants and microorganisms producing a wide variety of quinolone compounds have been discovered, several of which possess medicinally interesting properties ranging from antiallergenic and anticancer to antimicrobial activities. Over the years, these have served in the development of many synthetic drugs, including the successful fluoroquinolone antibiotics. Pseudomonas aeruginosa and related bacteria produce a number of 2-alkyl-4(1H)-quinolones, some of which exhibit antimicrobial activity. However, quinolones such as the Pseudomonas quinolone signal and 2-heptyl-4-hydroxyquinoline act as quorum-sensing signal molecules, controlling the expression of many virulence genes as a function of cell population density. Here, we review selectively this extensive family of bicyclic compounds, from natural and synthetic antimicrobials to signalling molecules, with a special emphasis on the biology of P. aeruginosa. In particular, we review their nomenclature and biochemistry, their multiple properties as membrane-interacting compounds, inhibitors of the cytochrome bc1 complex and iron chelators, as well as the regulation of their biosynthesis and their integration into the intricate quorum-sensing regulatory networks governing virulence and secondary metabolite gene expression.
Collapse
Affiliation(s)
- Stephan Heeb
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham, UK
| | | | | | | | | | | |
Collapse
|
38
|
Dusane DH, Zinjarde SS, Venugopalan VP, McLean RJC, Weber MM, Rahman PKSM. Quorum sensing: implications on rhamnolipid biosurfactant production. Biotechnol Genet Eng Rev 2011; 27:159-84. [PMID: 21415897 DOI: 10.1080/02648725.2010.10648149] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Quorum sensing (QS) has received significant attention in the past few decades. QS describes population density dependent cell to cell communication in bacteria using diffusible signal molecules. These signal molecules produced by bacterial cells, regulate various physiological processes important for social behavior and pathogenesis. One such process regulated by quorum sensing molecules is the production of a biosurfactant, rhamnolipid. Rhamnolipids are important microbially derived surface active agents produced by Pseudomonas spp. under the control of two interrelated quorum sensing systems; namely las and rhl. Rhamnolipids possess antibacterial, antifungal and antiviral properties. They are important in motility, cell to cell interactions, cellular differentiation and formation of water channels that are characteristics of Pseudomonas biofilms. Rhamnolipids have biotechnological applications in the uptake of hydrophobic substrates, bioremediation of contaminated soils and polluted waters. Rhamnolipid biosurfactants are biodegradable as compared to chemical surfactants and hence are more preferred in environmental applications. In this review, we examine the biochemical and genetic mechanism of rhamnolipid production by P. aeruginosa and propose the application of QS signal molecules in enhancing the rhamnolipid production.
Collapse
Affiliation(s)
- Devendra H Dusane
- Institute of Bioinformatics and Biotechnology, University of Pune, India.
| | | | | | | | | | | |
Collapse
|
39
|
Affiliation(s)
- Holly Huse
- Department of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas 78712
| | - Marvin Whiteley
- Department of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, Texas 78712
| |
Collapse
|
40
|
|
41
|
Effects of carbon and nitrogen sources on the proteome of Pseudomonas aeruginosa PA1 during rhamnolipid production. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.05.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
42
|
D'aes J, De Maeyer K, Pauwelyn E, Höfte M. Biosurfactants in plant-Pseudomonas interactions and their importance to biocontrol. ENVIRONMENTAL MICROBIOLOGY REPORTS 2010; 2:359-72. [PMID: 23766108 DOI: 10.1111/j.1758-2229.2009.00104.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Production of biosurfactants is a common feature in bacteria, and in particular in plant-associated species. These bacteria include many plant beneficial and plant pathogenic Pseudomonas spp., which produce primarily cyclic lipopeptide and rhamnolipid type biosurfactants. Pseudomonas-derived biosurfactants are involved in many important bacterial functions. By modifying surface properties, biosurfactants can influence common traits such as surface motility, biofilm formation and colonization. Biosurfactants can alter the bio-availability of exogenous compounds, such as nutrients, to promote their uptake, and of endogenous metabolites, including phenazine antibiotics, resulting in an enhanced biological activity. Antibiotic activity of biosurfactants towards microbes could play a role in intraspecific competition, self-defence and pathogenesis. In addition, bacterial surfactants can affect plants in different ways, either protecting them from disease, or acting as a toxin in a plant-pathogen interaction. Biosurfactants are involved in the biocontrol activity of an increasing number of Pseudomonas strains. Consequently, further insight into the roles and activities of surfactants produced by bacteria could provide means to optimize the use of biological control as an alternative crop protection strategy.
Collapse
Affiliation(s)
- Jolien D'aes
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 653, B-9000 Ghent, Belgium
| | | | | | | |
Collapse
|
43
|
The small RNA chaperone Hfq is required for the virulence of Yersinia pseudotuberculosis. Infect Immun 2010; 78:2034-44. [PMID: 20231416 DOI: 10.1128/iai.01046-09] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Bacterial small, noncoding RNAs (sRNAs) participate in the posttranscriptional regulation of gene expression, often by affecting protein translation, transcript stability, and/or protein activity. For proper function, many sRNAs rely on the chaperone Hfq, which mediates the interaction of the sRNA with its target mRNA. Recent studies have demonstrated that Hfq contributes to the pathogenesis of a number of bacterial species, suggesting that sRNAs play an essential role in the regulation of virulence. The enteric pathogen Yersinia pseudotuberculosis causes the disease yersiniosis. Here we show that Hfq is required by Y. pseudotuberculosis to cause mortality in an intragastric mouse model of infection, and a strain lacking Hfq is attenuated 1,000-fold compared to the wild type. Hfq is also required for virulence through the intraperitoneal route of infection and for persistence of the bacterium in the Peyer's patches, mesenteric lymph nodes, and spleen, suggesting a role for Hfq in systemic infection. Furthermore, the Deltahfq mutant of Y. pseudotuberculosis is hypermotile and displays increased production of a biosurfactant-like substance, reduced intracellular survival in macrophages, and decreased production of type III secretion effector proteins. Together, these data demonstrate that Hfq plays a critical role in the virulence of Y. pseudotuberculosis by participating in the regulation of multiple steps in the pathogenic process and further highlight the unique role of Hfq in the virulence of individual pathogens.
Collapse
|
44
|
Pustelny C, Albers A, Büldt-Karentzopoulos K, Parschat K, Chhabra SR, Cámara M, Williams P, Fetzner S. Dioxygenase-mediated quenching of quinolone-dependent quorum sensing in Pseudomonas aeruginosa. ACTA ACUST UNITED AC 2010; 16:1259-67. [PMID: 20064436 DOI: 10.1016/j.chembiol.2009.11.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 10/29/2009] [Accepted: 11/02/2009] [Indexed: 01/19/2023]
Abstract
2-Heptyl-3-hydroxy-4(1H)-quinolone (PQS) is a quorum-sensing signal molecule used by Pseudomonas aeruginosa. The structural similarity between 3-hydroxy-2-methyl-4(1H)-quinolone, the natural substrate for the 2,4-dioxygenase, Hod, and PQS prompted us to investigate whether Hod quenched PQS signaling. Hod is capable of catalyzing the conversion of PQS to N-octanoylanthranilic acid and carbon monoxide. In P. aeruginosa PAO1 cultures, exogenously supplied Hod protein reduced expression of the PQS biosynthetic gene pqsA, expression of the PQS-regulated virulence determinants lectin A, pyocyanin, and rhamnolipids, and virulence in planta. However, the proteolytic cleavage of Hod by extracellular proteases, competitive inhibition by the PQS precursor 2-heptyl-4(1H)-quinolone, and PQS binding to rhamnolipids reduced the efficiency of Hod as a quorum-quenching agent. Nevertheless, these data indicate that enzyme-mediated PQS inactivation has potential as an antivirulence strategy against P. aeruginosa.
Collapse
Affiliation(s)
- Christian Pustelny
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Kim K, Kim YU, Koh BH, Hwang SS, Kim SH, Lépine F, Cho YH, Lee GR. HHQ and PQS, two Pseudomonas aeruginosa quorum-sensing molecules, down-regulate the innate immune responses through the nuclear factor-kappaB pathway. Immunology 2009; 129:578-88. [PMID: 20102415 DOI: 10.1111/j.1365-2567.2009.03160.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
To explore whether bacterial secreted 4-hydroxy-2-alkylquinolines (HAQs) can regulate host innate immune responses, we used the extracts of bacterial culture supernatants from a wild-type (PA14) and two mutants of Pseudomonas aeruginosa that have defects in making HAQs. Surprisingly, the extract of supernatants from the P. aeruginosa pqsA mutant that does not make HAQs showed strong stimulating activity for the production of innate cytokines such as tumour necrosis factor-alpha and interleukin-6 in the J774A.1 mouse monocyte/macrophage cell line, whereas the extract from the wild-type did not. The addition of 4-hydroxy-2-heptylquinoline (HHQ) or 2-heptyl-3,4-dihydroxyquinoline (PQS, Pseudomonas quinolone signal) to mammalian cell culture media abolished this stimulating activity of the extracts of supernatants from the pqsA mutant on the expression of innate cytokines in J774A.1 cells and in the primary bronchoalveolar lavage cells from C57BL/6 mice, suggesting that HHQ and PQS can suppress the host innate immune responses. The pqsA mutant showed reduced dissemination in the lung tissue compared with the wild-type strain in a mouse in vivo intranasal infection model, suggesting that HHQ and PQS may play a role in the pathogenicity of P. aeruginosa. HHQ and PQS reduced the nuclear factor-kappaB (NF-kappaB) binding to its binding sites and the expression of NF-kappaB target genes, and PQS delayed inhibitor of kappaB degradation, indicating that the effect of HHQ and PQS was mediated through the NF-kappaB pathway. Our results suggest that HHQ and PQS produced by P. aeruginosa actively suppress host innate immune responses.
Collapse
Affiliation(s)
- Kiwan Kim
- Department of Life Science, Sogang University, Seoul, Korea
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Bazire A, Diab F, Taupin L, Rodrigues S, Jebbar M, Dufour A. Effects of osmotic stress on rhamnolipid synthesis and time-course production of cell-to-cell signal molecules by Pseudomonas aeruginosa. Open Microbiol J 2009; 3:128-35. [PMID: 19707523 PMCID: PMC2730030 DOI: 10.2174/1874285800903010128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 07/20/2009] [Accepted: 07/23/2009] [Indexed: 12/28/2022] Open
Abstract
Biosynthesis of biosurfactant rhamnolipids by Pseudomonas aeruginosa depends on two hierarchical quorum sensing systems, LasRI and RhlRI, which synthesize and sense the signal molecules N-(3-oxododecanoyl)-L-homoserine lactone (3OC12-HSL) and N-butyryl-L-homoserine lactone (C4-HSL), respectively. The Pseudomonas Quinolone Signal (PQS) is a third cell-to-cell signal molecule connecting these two systems, and its precursor, 2-heptyl-4-quinolone (HHQ), also constitutes a signal. The chronology of the production of signal molecules and rhamnolipids was determined during growth in PPGAS medium. Hyperosmotic condition (0.5 M NaCl) moderately affected growth, and led to intra-cellular accumulation of compatible solutes. Production of signal molecules was delayed and their highest concentrations were 2.5 to 5 fold lower than in NaCl-free PPGAS, except for HHQ, the highest concentration of which was increased. The presence of NaCl prevented rhamnolipid synthesis. When the osmoprotectant glycine betaine was added to PPGAS/NaCl medium, it was imported by the cells without being metabolized. This did not improve growth, but reestablished the time-courses of HSL and HHQ accumulation and fully or partially restored the HSL and PQS levels. It also partially restored rhamnolipid production. Quantification of mRNAs encoding enzymes involved in HSL, PQS, and rhamnolipid biosyntheses confirmed the effect of hyperosmotic stress and glycine betaine at the gene expression level.
Collapse
Affiliation(s)
- Alexis Bazire
- Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, UEB, BP 92116, 56321 Lorient, France
| | | | | | | | | | | |
Collapse
|
47
|
Red death in Caenorhabditis elegans caused by Pseudomonas aeruginosa PAO1. Proc Natl Acad Sci U S A 2009; 106:6327-32. [PMID: 19369215 DOI: 10.1073/pnas.0813199106] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During host injury, Pseudomonas aeruginosa can be cued to express a lethal phenotype within the intestinal tract reservoir-a hostile, nutrient scarce environment depleted of inorganic phosphate. Here we determined if phosphate depletion activates a lethal phenotype in P. aeruginosa during intestinal colonization. To test this, we allowed Caenorhabditis elegans to feed on lawns of P. aeruginosa PAO1 grown on high and low phosphate media. Phosphate depletion caused PAO1 to kill 60% of nematodes whereas no worms died on high phosphate media. Unexpectedly, intense redness was observed in digestive tubes of worms before death. Using a combination of transcriptome analyses, mutants, and reporter constructs, we identified 3 global virulence systems that were involved in the "red death" response of P. aeruginosa during phosphate depletion; they included phosphate signaling (PhoB), the MvfR-PQS pathway of quorum sensing, and the pyoverdin iron acquisition system. Activation of all 3 systems was required to form a red colored PQS+Fe(3+) complex which conferred a lethal phenotype in this model. When pyoverdin production was inhibited in P. aeruginosa by providing excess iron, red death was attenuated in C. elegans and mortality was decreased in mice intestinally inoculated with P. aeruginosa. Introduction of the red colored PQS+Fe(3+) complex into the digestive tube of C. elegans or mouse intestine caused mortality associated with epithelial disruption and apoptosis. In summary, red death in C. elegans reveals a triangulated response between PhoB, MvfR-PQS, and pyoverdin in response to phosphate depletion that activates a lethal phenotype in P. aeruginosa.
Collapse
|
48
|
Williams P, Cámara M. Quorum sensing and environmental adaptation in Pseudomonas aeruginosa: a tale of regulatory networks and multifunctional signal molecules. Curr Opin Microbiol 2009; 12:182-91. [PMID: 19249239 DOI: 10.1016/j.mib.2009.01.005] [Citation(s) in RCA: 535] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Revised: 01/19/2009] [Accepted: 01/22/2009] [Indexed: 11/24/2022]
|
49
|
|
50
|
Surface translocation by Legionella pneumophila: a form of sliding motility that is dependent upon type II protein secretion. J Bacteriol 2008; 191:1537-46. [PMID: 19114479 DOI: 10.1128/jb.01531-08] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Legionella pneumophila exhibits surface translocation when it is grown on a buffered charcoal yeast extract (BCYE) containing 0.5 to 1.0% agar. After 7 to 22 days of incubation, spreading legionellae appear in an amorphous, lobed pattern that is most manifest at 25 to 30 degrees C. All nine L. pneumophila strains examined displayed the phenotype. Surface translocation was also exhibited by some, but not all, other Legionella species examined. L. pneumophila mutants that were lacking flagella and/or type IV pili behaved as the wild type did when plated on low-percentage agar, indicating that the surface translocation is not swarming or twitching motility. A translucent film was visible atop the BCYE agar, advancing ahead of the spreading legionellae. Based on its abilities to disperse water droplets and to promote the spreading of heterologous bacteria, the film appeared to manipulate surface tension and, as such, acted like a surfactant. Indeed, a sample obtained from the film rapidly dispersed when it was spotted onto a plastic surface. L. pneumophila type II secretion (Lsp) mutants, but not their complemented derivatives, were defective for both surface translocation and film production. In contrast, mutants defective for type IV secretion exhibited normal surface translocation. When lsp mutants were spotted onto film produced by the wild type, they were able to spread, suggesting that type II secretion promotes the elaboration of the Legionella surfactant. Together, these data indicate that L. pneumophila exhibits a form of surface translocation that is most akin to "sliding motility" and uniquely dependent upon type II secretion.
Collapse
|