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Gosset-Erard C, Han G, Kyrko D, Hueber A, Nay B, Eparvier V, Touboul D. Structural characterization of N-acyl-homoserine lactones from bacterial quorum sensing using LC-MS/MS analyses after Paternò-Büchi derivatization in solution. Anal Bioanal Chem 2024:10.1007/s00216-024-05355-0. [PMID: 38842688 DOI: 10.1007/s00216-024-05355-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/05/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024]
Abstract
Bacterial quorum sensing is a chemical language allowing bacteria to interact through the excretion of molecules called autoinducers, like N-acyl-homoserine lactones (AHLs) produced by Gram-negative Burkholderia and Paraburkholderia bacteria known as opportunistic pathogens. The AHLs differ in their acyl-chain length and may be modified by a 3-oxo or 3-hydroxy substituent, or C = C double bonds at different positions. As the bacterial signal specificity depends on all of these chemical features, their structural characterization is essential to have a better understanding of the population regulation and virulence phenomenon. This study aimed at enabling the localization of the C = C double bond on such specialized metabolites while using significantly lower amounts of biological material. The approach is based on LC-MS/MS analyses of bacterial extracts after in-solution derivatization by a photochemical Paternò-Büchi reaction, leading to the formation of an oxetane ring and subsequently to specific fragmentations when performing MS/MS experiments. The in-solution derivatization of AHLs was optimized on several standards, and then the matrix effect of bacterial extracts on the derivatization was assessed. As a proof of concept, the optimized conditions were applied to a bacterial extract enabling the localization of C = C bonds on unsaturated AHLs.
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Affiliation(s)
- Clarisse Gosset-Erard
- Université Paris-Saclay, CNRS, Institut de Chimie Des Substances Naturelles, UPR 2301, 91198, Gif-Sur-Yvette, France
| | - Guanghui Han
- Laboratoire de Synthèse Organique (LSO), CNRS UMR 7652, Ecole Polytechnique, ENSTA, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Dimitra Kyrko
- Université Paris-Saclay, CNRS, Institut de Chimie Des Substances Naturelles, UPR 2301, 91198, Gif-Sur-Yvette, France
| | - Amandine Hueber
- Université Paris-Saclay, CNRS, Institut de Chimie Des Substances Naturelles, UPR 2301, 91198, Gif-Sur-Yvette, France
| | - Bastien Nay
- Laboratoire de Synthèse Organique (LSO), CNRS UMR 7652, Ecole Polytechnique, ENSTA, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Véronique Eparvier
- Université Paris-Saclay, CNRS, Institut de Chimie Des Substances Naturelles, UPR 2301, 91198, Gif-Sur-Yvette, France
| | - David Touboul
- Université Paris-Saclay, CNRS, Institut de Chimie Des Substances Naturelles, UPR 2301, 91198, Gif-Sur-Yvette, France.
- Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168, Ecole Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau, France.
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2
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Sompiyachoke K, Elias MH. Engineering quorum quenching acylases with improved kinetic and biochemical properties. Protein Sci 2024; 33:e4954. [PMID: 38520282 PMCID: PMC10960309 DOI: 10.1002/pro.4954] [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: 10/25/2023] [Revised: 01/03/2024] [Accepted: 02/21/2024] [Indexed: 03/25/2024]
Abstract
Many Gram-negative bacteria use N-acyl-L-homoserine lactone (AHL) signals to coordinate phenotypes such as biofilm formation and virulence factor production. Quorum-quenching enzymes, such as AHL acylases, chemically degrade these molecules which prevents signal reception by bacteria and inhibits undesirable biofilm-related traits. These capabilities make acylases appealing candidates for controlling microbes, yet candidates with high activity levels and substrate specificity and that are capable of being formulated into materials are needed. In this work, we undertook engineering efforts against two AHL acylases, PvdQ and MacQ, to generate these improved properties using the Protein One-Stop Shop Server. The engineering of acylases is complicated by low-throughput enzymatic assays. Alleviating this challenge, we report a time-course kinetic assay for AHL acylases that monitors the real-time production of homoserine lactone. Using the assay, we identified variants of PvdQ that were significantly stabilized, with melting point increases of up to 13.2°C, which translated into high resistance against organic solvents and increased compatibility with material coatings. While the MacQ mutants were unexpectedly destabilized, they had considerably improved kinetic properties, with >10-fold increases against N-butyryl-L-homoserine lactone and N-hexanoyl-L-homoserine lactone. Accordingly, these changes resulted in increased quenching abilities using a biosensor model and greater inhibition of virulence factor production of Pseudomonas aeruginosa PA14. While the crystal structure of one of the MacQ variants, M1, did not reveal obvious structural determinants explaining the observed changes in kinetics, it allowed for the capture of an acyl-enzyme intermediate that confirms a previously hypothesized catalytic mechanism of AHL acylases.
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Affiliation(s)
- Kitty Sompiyachoke
- Department of Biochemistry, Molecular Biology and BiophysicsUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Mikael H. Elias
- Department of Biochemistry, Molecular Biology and BiophysicsUniversity of MinnesotaSt. PaulMinnesotaUSA
- Biotechnology InstituteSt. PaulMinnesotaUSA
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3
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Gómez AC, Horgan C, Yero D, Bravo M, Daura X, O'Driscoll M, Gibert I, O'Sullivan TP. Synthesis and evaluation of aromatic BDSF bioisosteres on biofilm formation and colistin sensitivity in pathogenic bacteria. Eur J Med Chem 2023; 261:115819. [PMID: 37748387 DOI: 10.1016/j.ejmech.2023.115819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023]
Abstract
The diffusible signal factor family (DSF) of molecules play an important role in regulating intercellular communication, or quorum sensing, in several disease-causing bacteria. These messenger molecules, which are comprised of cis-unsaturated fatty acids, are involved in the regulation of biofilm formation, antibiotic tolerance, virulence and the control of bacterial resistance. We have previously demonstrated how olefinic N-acyl sulfonamide bioisosteric analogues of diffusible signal factor can reduce biofilm formation or enhance antibiotic sensitivity in a number of bacterial strains. This work describes the design and synthesis of a second generation of aromatic N-acyl sulfonamide bioisosteres. The impact of these compounds on biofilm production in Acinetobacter baumannii, Escherichia coli, Burkholderia multivorans, Burkholderia cepacia, Burkholderia cenocepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia is evaluated, in addition to their effects on antibiotic tolerance. The ability of these molecules to increase survival rates on co-administration with colistin is also investigated using the Galleria infection model.
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Affiliation(s)
- Andromeda-Celeste Gómez
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Conor Horgan
- School of Chemistry, University College Cork, Cork, Ireland
| | - Daniel Yero
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marc Bravo
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xavier Daura
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, Cerdanyola de Vallès, Spain
| | - Michelle O'Driscoll
- School of Chemistry, University College Cork, Cork, Ireland; School of Pharmacy, University College Cork, Cork, Ireland; Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Timothy P O'Sullivan
- School of Chemistry, University College Cork, Cork, Ireland; School of Pharmacy, University College Cork, Cork, Ireland; Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland.
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Yin L, Wang Y, Xiang S, Xu K, Wang B, Jia AQ. Tyramine, one quorum sensing inhibitor, reduces pathogenicity and restores tetracycline susceptibility in Burkholderia cenocepacia. Biochem Pharmacol 2023; 218:115906. [PMID: 37951366 DOI: 10.1016/j.bcp.2023.115906] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/22/2023] [Accepted: 11/01/2023] [Indexed: 11/14/2023]
Abstract
Burkholderia cenocepacia is an opportunistic respiratory pathogen of particular relevance to patients with cystic fibrosis (CF), primarily regulating its biological functions and virulence factors through two quorum sensing (QS) systems (CepI/R and CciI/R). The highly persistent incidence of multidrug resistant Burkholderia cenocepacia poses a global threat to public health. In this study, we investigated the effects of tyramine, one biogenic amine, on the QS systems of Burkholderia cenocepacia. Genetic and biochemical analyses revealed that tyramine inhibited the production of N-hexanoyl-homoserine (AHL) signaling molecules (C8-HSL and C6-HSL) by blocking the CepI/R and CciI/R systems. As a result, the inhibition of QS systems leads to reduced production of various virulence factors, such as biofilm formation, extracellular polysaccharides, lipase, and swarming motility. Notably, as a potential quorum sensing inhibitor, tyramine exhibits low toxicity in vivo in Galleria mellonella larvae and is well characterized by Lipinski's five rules. It also shows high gastrointestinal absorption and the ability to cross the blood-brain barrier according to SwissADME database and ProTox-II server. Additionally, tyramine was found to enhance the efficacy of tetracycline in reducing the infectivity of Burkholderia cenocepacia in Galleria mellonella larvae infection model. Therefore, tyramine could be a promising candidate for combination therapy with traditional antimicrobials to improve their effectiveness against Burkholderia cenocepacia.
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Affiliation(s)
- Lujun Yin
- Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou 570311, China; Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
| | - Yingjie Wang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
| | - Shiliang Xiang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
| | - Kaizhong Xu
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
| | - Bo Wang
- Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou 570311, China
| | - Ai-Qun Jia
- Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou 570311, China.
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Ghosh D, Seth M, Mondal P, Mukhopadhyay SK. Biocontrol of biofilm forming Burkholderia cepacia using a quorum quenching crude lactonase enzyme extract from a marine Chromohalobacter sp. strain D23. Arch Microbiol 2023; 205:374. [PMID: 37935892 DOI: 10.1007/s00203-023-03712-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/04/2023] [Accepted: 10/16/2023] [Indexed: 11/09/2023]
Abstract
Biofilm plays advantageous role in Burkholderia cepacia by exerting multi-drug resistance. As quorum sensing (QS) system regulates biofilm formation and pathogenicity in B. cepacia strains, quorum quenching (QQ) may be a novel strategy to control persistent B. cepacia infections. In these regards, 120 halophilic bacteria were isolated from marine sample and tested using Chromobacterium violaceum and C. violaceum CV026-based bioassays initially, showing reduced violacein synthesis by QQ enzyme by 6 isolates. Among them, Chromohalobacter sp. D23 significantly degraded both C6-homoserine lactone (C6-HSL) and C8-HSL due to potent lactonase activity, which was detected by C. violaceum CV026 biosensor. Further high-performance liquid chromatography (HPLC) study confirmed degradation of N-acyl homoserine lactones (N-AHLs) particularly C6-HSL and C8-HSL by crude lactonase enzyme. Chromohalobacter sp. D23 reduced biofilm formation in terms of decreased total biomass and viability in biofilm-embedded cells in B. cepacia significantly which was also evidenced by fluorescence microscopic images. An increase in antibiotic susceptibility of B. cepacia biofilm was achieved when crude lactonase enzyme of Chromohalobacter sp. strain D23 was combined with chloramphenicol (1-5 × MIC). Chromohalobacter sp. D23 also showed prominent decrease in QS-mediated synthesis of virulence factors such as extracellular polymeric substances (EPS), extracellular protease, and hemolysin in B. cepacia. Again crude lactonase enzyme of Chromohalobacter sp. strain D23 inhibited B. cepacia biofilm formation inside nasal oxygen catheters in vitro. Finally, antibiotic susceptibility test and virulence tests revealed sensitivity of Chromohalobacter sp. strain D23 against a wide range of conventional antibiotics as well as absence of gelatinolytic, hemolytic, and serum coagulating activities. Therefore, the current study shows potential quorum quenching as well as anti-biofilm activity of Chromohalobacter sp. D23 against B. cepacia.
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Affiliation(s)
- Dhritishree Ghosh
- Department of Microbiology, The University of Burdwan, Purba Bardhaman, Burdwan, West Bengal, 713104, India
| | - Madhupa Seth
- Department of Microbiology, The University of Burdwan, Purba Bardhaman, Burdwan, West Bengal, 713104, India
| | - Priyajit Mondal
- Department of Microbiology, The University of Burdwan, Purba Bardhaman, Burdwan, West Bengal, 713104, India
| | - Subhra Kanti Mukhopadhyay
- Department of Microbiology, The University of Burdwan, Purba Bardhaman, Burdwan, West Bengal, 713104, India.
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6
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Cacchio P, Pellegrini M, Farda B, Djebaili R, Tabacchioni S, Del Gallo M. Preliminary indication of the role of AHL-dependent quorum sensing systems in calcium carbonate precipitation in Gram-negative bacteria. AIMS Microbiol 2023; 9:692-711. [PMID: 38173968 PMCID: PMC10758570 DOI: 10.3934/microbiol.2023035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/25/2023] [Accepted: 09/04/2023] [Indexed: 01/05/2024] Open
Abstract
Numerous microbial species participate in precipitation of carbonates in various natural environments, including soils, geological formations, freshwater biofilms and oceans. Despite the geochemical interest of such a biomineralization process, its molecular mechanisms and adaptive aspects remain poorly known. Many Gram-negative bacteria use cell-to-cell communication systems relying on N-acylhomoserine lactone (AHLs) signal molecules to express certain phenotypic traits in a density-dependent manner, a phenomenon referred as to quorum-sensing (QS). In this work, bacterial isolates collected from cave and rhizosphere soil were analyzed to study the occurrence of the AHL-mediated QS in bacterial calcium carbonate (CaCO3) precipitation. To test the production of AHLs signal molecules, we cross-streaked Gram-negative calcifying strains, selected among the environmental strains studied, with the AHL-negative mutant Chromobacterium subtsugae strain CV026. Only Burkholderia ambifaria LMG 11351 was able to restore violacein production in CV026 among the tested strains. The constructed AHL-negative mutant of B. ambifaria LMG 11351 could not precipitate CaCO3 on B-4 agar. Scanning Electron Microscopy (SEM) analysis on CaCO3 crystals obtained in vitro shows crystals of different morphologies, calcified biofilms and bacteria in close contact with the precipitated crystals. In the inner layers of the bioliths deposited by B. ambifaria LMG 11351, a stream-like organization of the Burkholderia imprints was not detected by SEM. Our data provide preliminary evidence that the activation of AHL-regulated genes may be a prerequisite for in vitro bacterial carbonatogenesis, in some cases, confirming the specific role of bacteria as CaCO3 precipitating agents. We enhance the understanding of bacterial CaCO3 biomineralization and its potential biotechnology implications for QS-based strategies to enhance or decrease CaCO3 precipitation through specific bacterial processes. The AHL-negative mutant of B. ambifaria LMG 11351 (a well-known plant growth-promoting bacterium) could also be used to study plant-bacteria interactions. The adaptive role of bacterial CaCO3 biomineralization was also discussed.
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Affiliation(s)
- Paola Cacchio
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Coppito, 67100 L'Aquila, Italy
| | - Marika Pellegrini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Coppito, 67100 L'Aquila, Italy
| | - Beatrice Farda
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Coppito, 67100 L'Aquila, Italy
| | - Rihab Djebaili
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Coppito, 67100 L'Aquila, Italy
| | - Silvia Tabacchioni
- Division Biotechnologies and Agroindustry, ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), C.R. Casaccia, 000123 Rome, Italy
| | - Maddalena Del Gallo
- Department of Life, Health and Environmental Sciences, University of L'Aquila, Coppito, 67100 L'Aquila, Italy
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Sompiyachoke K, Elias MH. Engineering Quorum Quenching Acylases with Improved Kinetic and Biochemical Properties. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555929. [PMID: 37693529 PMCID: PMC10491313 DOI: 10.1101/2023.09.01.555929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Many Gram-negative bacteria respond to N-acyl-L-homoserine lactone (AHL) signals to coordinate phenotypes such as biofilm formation and virulence factor production. Quorum-quenching enzymes, such as acylases, chemically degrade AHL signals, prevent signal reception by bacteria, and inhibit undesirable traits related to biofilm. These capabilities make these enzymes appealing candidates for controlling microbes. Yet, enzyme candidates with high activity levels, high substrate specificity for specific interference, and that are capable of being formulated into materials are needed. In this work, we undertook engineering efforts against two AHL acylases, PvdQ and MacQ, to obtain improved acylase variants. The engineering of acylase is complicated by low-throughput enzymatic assays. To alleviate this challenge, we report a time-course kinetic assay for AHL acylase that tracks the real-time production of homoserine lactone. Using the protein one-stop shop server (PROSS), we identified variants of PvdQ that were significantly stabilized, with melting point increases of up to 13.2 °C, which translated into high resistance against organic solvents and increased compatibility with material coatings. We also generated mutants of MacQ with considerably improved kinetic properties, with >10-fold increases against N-butyryl-L-homoserine lactone and N-hexanoyl-L-homoserine lactone. In fact, the variants presented here exhibit unique combinations of stability and activity levels. Accordingly, these changes resulted in increased quenching abilities using a biosensor model and greater inhibition of virulence factor production of Pseudomonas aeruginosa PA14. While the crystal structure of one of the MacQ variants, M1, did not reveal obvious structural determinants explaining the observed changes in kinetics, it allowed for the capture of an acyl-enzyme intermediate that confirms a previously hypothesized catalytic mechanism of AHL acylases.
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Affiliation(s)
- Kitty Sompiyachoke
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, St. Paul, MN, 55108, USA
| | - Mikael H. Elias
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics, St. Paul, MN, 55108, USA
- University of Minnesota, Biotechnology Institute, St. Paul, MN, 55108, USA
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8
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Kim E, Jung HI, Park SH, Kim HY, Kim SK. Comprehensive genome analysis of Burkholderia contaminans SK875, a quorum-sensing strain isolated from the swine. AMB Express 2023; 13:30. [PMID: 36899131 PMCID: PMC10006387 DOI: 10.1186/s13568-023-01537-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/04/2023] [Indexed: 03/12/2023] Open
Abstract
The Burkholderia cepacia complex (BCC) is a Gram-negative bacterial, including Burkholderia contaminans species. Although the plain Burkholderia is pervasive from taxonomic and genetic perspectives, a common characteristic is that they may use the quorum-sensing (QS) system. In our previous study, we generated the complete genome sequence of Burkholderia contaminans SK875 isolated from the respiratory tract. To our knowledge, this is the first study to report functional genomic features of B. contaminans SK875 for understanding the pathogenic characteristics. In addition, comparative genomic analysis for five B. contaminans genomes was performed to provide comprehensive information on the disease potential of B. contaminans species. Analysis of average nucleotide identity (ANI) showed that the genome has high similarity (> 96%) with other B. contaminans strains. Five B. contaminans genomes yielded a pangenome of 8832 coding genes, a core genome of 5452 genes, the accessory genome of 2128 genes, and a unique genome of 1252 genes. The 186 genes were specific to B. contaminans SK875, including toxin higB-2, oxygen-dependent choline dehydrogenase, and hypothetical proteins. Genotypic analysis of the antimicrobial resistance of B. contaminans SK875 verified resistance to tetracycline, fluoroquinolone, and aminoglycoside. Compared with the virulence factor database, we identified 79 promising virulence genes such as adhesion system, invasions, antiphagocytic, and secretion systems. Moreover, 45 genes of 57 QS-related genes that were identified in B. contaminans SK875 indicated high sequence homology with other B. contaminans strains. Our results will help to gain insight into virulence, antibiotic resistance, and quorum sensing for B. contaminans species.
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Affiliation(s)
- Eiseul Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Hae-In Jung
- Department of Animal Sciences and Technology, Konkuk University, Seoul, 05029, Korea
| | - Si Hong Park
- Department of Food Science and Technology, Oregon State University, Corvallis, OR, 97331, USA
| | - Hae-Yeong Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, Korea.
| | - Soo-Ki Kim
- Department of Animal Sciences and Technology, Konkuk University, Seoul, 05029, Korea.
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Horáček O, Portillo AE, Dhaubhadel U, Sung YS, Readel ER, Kučera R, Armstrong DW. Comprehensive chiral GC-MS/MS and LC-MS/MS methods for identification and determination of N-acyl homoserine lactones. Talanta 2023; 253:123957. [PMID: 36215752 DOI: 10.1016/j.talanta.2022.123957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 12/13/2022]
Abstract
N-acyl homoserine lactones (N-HLs) are signaling molecules synthesized by gram-negative bacteria to communicate in a process called quorum sensing. Most reported methods for the analysis of N-HLs, which are chiral molecules, do not distinguish between enantiomers. Typical examples include biosensors, liquid chromatography with UV detection, gas chromatography coupled with a mass spectrometer (GC-MS) and liquid chromatography coupled with mass spectrometer (LC-MS). Recently, the production of both D,L-N-HLs have been reported in Vibrio fischeri and Burkholderia cepacia. Concentrations of the D-N-HLs were found at the limit of quantification for the employed method. Therefore, for further studies of the role of the D-N-HLs in bacterial physiology, more sensitive, reliable, and selective analytical methods are necessary. In this work, such comprehensive chiral analytical methods for the identification and determination of 18 N-HLs using solid phase extraction followed by GC-MS/MS and LC-MS/MS analyses were developed. Extraction recoveries for the more hydrophilic C4 N-HLs were <10% of all other N-HLs, thus offering a possible explanation as to their lack of detection in previous studies. The chiral separations of all 18 N-HLs derivatives were accomplished by the complementary GC-MS/MS and LC-MS/MS methods. The limit of detection for LC-MS/MS method was as low as 1 ppb. The limit of detection for the GC-MS/MS method was found to be one to three orders of magnitude higher than the LC-MS/MS method. Due to the high extraction recovery and a preconcentration factor of 100, concentrations as low as 10 ppt can be detected by LC-MS/MS in biological samples. The LC-MS/MS approach provided greater enantioselectivity for the larger, more hydrophobic N-HLs while GC-MS/MS provided better enantioselectivity for the smaller N-HLs.
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Affiliation(s)
- Ondřej Horáček
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA; Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy, Hradec Kralove, Czech Republic
| | - Abiud E Portillo
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Umang Dhaubhadel
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Yu-Sheng Sung
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Elizabeth R Readel
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Radim Kučera
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy, Hradec Kralove, Czech Republic
| | - Daniel W Armstrong
- Department of Chemistry & Biochemistry, The University of Texas at Arlington, Arlington, TX, USA.
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10
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The BDSF quorum sensing receptor RpfR regulates Bep exopolysaccharide synthesis in Burkholderia cenocepacia via interaction with the transcriptional regulator BerB. NPJ Biofilms Microbiomes 2022; 8:93. [DOI: 10.1038/s41522-022-00356-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 11/07/2022] [Indexed: 11/24/2022] Open
Abstract
AbstractThe polysaccharide Bep is essential for in vitro biofilm formation of the opportunistic pathogen Burkholderia cenocepacia. We found that the Burkholderia diffusible signaling factor (BDSF) quorum sensing receptor RpfR is a negative regulator of the bep gene cluster in B. cenocepacia. An rpfR mutant formed wrinkled colonies, whereas additional mutations in the bep genes or known bep regulators like berA and berB restored the wild-type smooth colony morphology. We found that there is a good correlation between intracellular c-di-GMP levels and bep expression when the c-di-GMP level is increased or decreased through ectopic expression of a diguanylate cyclase or a c-di-GMP phosphodiesterase, respectively. However, when the intracellular c-di-GMP level is changed by site directed mutagenesis of the EAL or GGDEF domain of RpfR there is no correlation between intracellular c-di-GMP levels and bep expression. Except for rpfR, deletion mutants of all 25 c-di-GMP phosphodiesterase and diguanylate cyclase genes encoded by B. cenocepacia showed no change to berA and bep gene expression. Moreover, bacterial two-hybrid assays provided evidence that RpfR and BerB physically interact and give specificity to the regulation of the bep genes. We suggest a model where RpfR binds BerB at low c-di-GMP levels to sequester this RpoN-dependent activator to an RpfR/RpfF complex. If the c-di-GMP levels rise, possibly by the enzymatic action of RpfR, BerB binds c-di-GMP and is released from the RpfR/RpfF complex and associates with RpoN to activate transcription of berA, and the BerA protein subsequently activates transcription of the bep genes.
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Molecular Mechanisms and Applications of N-Acyl Homoserine Lactone-Mediated Quorum Sensing in Bacteria. Molecules 2022; 27:molecules27217584. [PMID: 36364411 PMCID: PMC9654057 DOI: 10.3390/molecules27217584] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
Microbial biodiversity includes biotic and abiotic components that support all life forms by adapting to environmental conditions. Climate change, pollution, human activity, and natural calamities affect microbial biodiversity. Microbes have diverse growth conditions, physiology, and metabolism. Bacteria use signaling systems such as quorum sensing (QS) to regulate cellular interactions via small chemical signaling molecules which also help with adaptation under undesirable survival conditions. Proteobacteria use acyl-homoserine lactone (AHL) molecules as autoinducers to sense population density and modulate gene expression. The LuxI-type enzymes synthesize AHL molecules, while the LuxR-type proteins (AHL transcriptional regulators) bind to AHLs to regulate QS-dependent gene expression. Diverse AHLs have been identified, and the diversity extends to AHL synthases and AHL receptors. This review comprehensively explains the molecular diversity of AHL signaling components of Pseudomonas aeruginosa, Chromobacterium violaceum, Agrobacterium tumefaciens, and Escherichia coli. The regulatory mechanism of AHL signaling is also highlighted in this review, which adds to the current understanding of AHL signaling in Gram-negative bacteria. We summarize molecular diversity among well-studied QS systems and recent advances in the role of QS proteins in bacterial cellular signaling pathways. This review describes AHL-dependent QS details in bacteria that can be employed to understand their features, improve environmental adaptation, and develop broad biomolecule-based biotechnological applications.
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Recipient Cell Factors Influence Interbacterial Competition Mediated by Two Distinct Burkholderia dolosa Contact-Dependent Growth Inhibition Systems. J Bacteriol 2022; 204:e0054121. [PMID: 36000834 PMCID: PMC9487645 DOI: 10.1128/jb.00541-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Contact-dependent growth inhibition (CDI) systems mediate interbacterial antagonism between Gram-negative bacteria by delivering the toxic portion of a large surface protein (termed BcpA in Burkholderia species) to the cytoplasm of neighboring bacteria. Translocation of the antibacterial polypeptide into recipient cells requires specific recipient outer and inner membrane proteins, but the identity of these factors outside several model organisms is unknown. To identify genes involved in CDI susceptibility in the Burkholderia cepacia complex member Burkholderia dolosa, a transposon mutagenesis selection approach was used to enrich for mutants resistant to BcpA-1 or BcpA-2. Subsequent analysis showed that candidate regulatory genes contributed modestly to recipient cell susceptibility to B. dolosa CDI. However, most candidate deletion mutants did not show the same phenotypes as the corresponding transposon mutants. Whole-genome resequencing revealed that these transposon mutants also contained unique mutations within a three gene locus (wabO, BDAG_01006, and BDAG_01005) encoding predicted lipopolysaccharide (LPS) biosynthesis enzymes. B. dolosa wabO, BDAG_01006, or BDAG_01005 mutants were resistant to CDI and produced LPS with altered core oligosaccharide and O-antigen. Although BcpA-1 and BcpA-2 are dissimilar and expected to utilize different outer membrane receptors, intoxication by both proteins was similarly impacted by LPS changes. Together, these findings suggest that alterations in cellular regulation may indirectly impact the efficiency of CDI-mediated competition and demonstrate that LPS is required for intoxication by two distinct B. dolosa BcpA proteins. IMPORTANCEContact-dependent growth inhibition (CDI) system proteins, produced by many Gram-negative bacteria, are narrow spectrum antimicrobials that inhibit the growth of closely related neighboring bacteria. Here, we use the opportunistic pathogen Burkholderia dolosa to identify genes required for intoxication by two distinct CDI system proteins. Our findings suggest that B. dolosa recipient cells targeted by CDI systems are only intoxicated if they produce full-length lipopolysaccharide. Understanding the mechanisms underlying antagonistic interbacterial interactions may contribute to future therapeutic development.
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The cis-2-dodecenoic acid (BDSF) quorum sensing system in Burkholderia cenocepacia. Appl Environ Microbiol 2022; 88:e0234221. [PMID: 34985987 DOI: 10.1128/aem.02342-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been demonstrated that quorum sensing (QS) is widely employed by bacterial cells to coordinately regulate various group behaviors. Diffusible signal factor (DSF)-type signals have emerged as a growing family of conserved cell-cell communication signals. In addition to the DSF signal initially identified in Xanthomonas campestris pv. campestris, Burkholderia diffusible signal factor (BDSF, cis-2-dodecenoic acid) has been recognized as a conserved DSF-type signal with specific characteristics in both signal perception and transduction from DSF signals. Here, we review the history and current progress of the research of this type of signal, especially focusing on its biosynthesis, signaling pathways, and biological functions. We also discuss and explore the huge potential of targeting this kind of QS system as a new therapeutic strategy to control bacterial infections and diseases.
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Metabolomic profiling of Burkholderia cenocepacia in synthetic cystic fibrosis sputum medium reveals nutrient environment-specific production of virulence factors. Sci Rep 2021; 11:21419. [PMID: 34725378 PMCID: PMC8560942 DOI: 10.1038/s41598-021-00421-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/12/2021] [Indexed: 12/13/2022] Open
Abstract
Infections by Burkholderia cenocepacia lead to life-threatening disease in immunocompromised individuals, including those living with cystic fibrosis (CF). While genetic variation in various B. cenocepacia strains has been reported, it remains unclear how the chemical environment of CF lung influences the production of small molecule virulence factors by these strains. Here we compare metabolomes of three clinical B. cenocepacia strains in synthetic CF sputum medium (SCFM2) and in a routine laboratory medium (LB), in the presence and absence of the antibiotic trimethoprim. Using a mass spectrometry-based untargeted metabolomics approach, we identify several compound classes which are differentially produced in SCFM2 compared to LB media, including siderophores, antimicrobials, quorum sensing signals, and various lipids. Furthermore, we describe that specific metabolites are induced in the presence of the antibiotic trimethoprim only in SCFM2 when compared to LB. Herein, C13-acyl-homoserine lactone, a quorum sensing signal previously not known to be produced by B. cenocepacia as well as pyochelin-type siderophores were exclusively detected during growth in SCFM2 in the presence of trimethoprim. The comparative metabolomics approach described in this study provides insight into environment-dependent production of secondary metabolites by B. cenocepacia strains and suggests future work which could identify personalized strain-specific regulatory mechanisms involved in production of secondary metabolites. Investigations into whether antibiotics with different mechanisms of action induce similar metabolic alterations will inform development of combination treatments aimed at effective clearance of Burkholderia spp. pathogens.
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15
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Current and Emerging Therapies to Combat Cystic Fibrosis Lung Infections. Microorganisms 2021; 9:microorganisms9091874. [PMID: 34576767 PMCID: PMC8466233 DOI: 10.3390/microorganisms9091874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 11/30/2022] Open
Abstract
The ultimate aim of any antimicrobial treatment is a better infection outcome for the patient. Here, we review the current state of treatment for bacterial infections in cystic fibrosis (CF) lung while also investigating potential new treatments being developed to see how they may change the dynamics of antimicrobial therapy. Treatment with antibiotics coupled with regular physical therapy has been shown to reduce exacerbations and may eradicate some strains. Therapies such as hypertonic saline and inhaled PulmozymeTM (DNase-I) improve mucus clearance, while modifier drugs, singly and more successfully in combination, re-open certain mutant forms of the cystic fibrosis transmembrane conductance regulator (CFTR) to enable ion passage. No current method, however, completely eradicates infection, mainly due to bacterial survival within biofilm aggregates. Lung transplants increase lifespan, but reinfection is a continuing problem. CFTR modifiers normalise ion transport for the affected mutations, but there is conflicting evidence on bacterial clearance. Emerging treatments combine antibiotics with novel compounds including quorum-sensing inhibitors, antioxidants, and enzymes, or with bacteriophages, aiming to disrupt the biofilm matrix and improve antibiotic access. Other treatments involve bacteriophages that target, infect and kill bacteria. These novel therapeutic approaches are showing good promise in vitro, and a few have made the leap to in vivo testing.
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16
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Ding L, Wang J, Cai S, Smyth H, Cui Z. Pulmonary biofilm-based chronic infections and inhaled treatment strategies. Int J Pharm 2021; 604:120768. [PMID: 34089796 DOI: 10.1016/j.ijpharm.2021.120768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/20/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
Certain pulmonary diseases, such as cystic fibrosis (CF), non-CF bronchiectasis, chronic obstructive pulmonary disease, and ventilator-associated pneumonia, are usually accompanied by respiratory tract infections due to the physiological alteration of the lung immunological defenses. Recurrent infections may lead to chronic infection through the formation of biofilms. Chronic biofilm-based infections are challenging to treat using antimicrobial agents. Therefore, effective ways to eradicate biofilms and thus relieve respiratory tract infection require the development of efficacious agents for biofilm destruction, the design of delivery carriers with biofilm-targeting and/or penetrating abilities for these agents, and the direct delivery of them into the lung. This review provides an in-depth description of biofilm-based infections caused by pulmonary diseases and focuses on current existing agents that are administered by inhalation into the lung to treat biofilm, which include i) inhalable antimicrobial agents and their combinations, ii) non-antimicrobial adjuvants such as matrix-targeting enzymes, mannitol, glutathione, cyclosporin A, and iii) liposomal formulations of anti-biofilm agents. Finally, novel agents that have shown promise against pulmonary biofilms as well as traditional and new devices for pulmonary delivery of anti-biofilm agents into the lung are also discussed.
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Affiliation(s)
- Li Ding
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jieliang Wang
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Shihao Cai
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA
| | - Hugh Smyth
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Zhengrong Cui
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA.
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A LysR Family Transcriptional Regulator Modulates Burkholderia cenocepacia Biofilm Formation and Protease Production. Appl Environ Microbiol 2021; 87:e0020221. [PMID: 33811025 PMCID: PMC8174753 DOI: 10.1128/aem.00202-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Quorum-sensing (QS) signals are widely employed by bacteria to regulate biological functions in response to cell densities. Previous studies showed that Burkholderia cenocepacia mostly utilizes two types of QS systems, including the N-acylhomoserine lactone (AHL) and cis-2-dodecenoic acid (BDSF) systems, to regulate biological functions. We demonstrated here that a LysR family transcriptional regulator, Bcal3178, controls the QS-regulated phenotypes, including biofilm formation and protease production, in B. cenocepacia H111. Expression of Bcal3178 at the transcriptional level was obviously downregulated in both the AHL-deficient and BDSF-deficient mutant strains compared to the wild-type H111 strain. It was further identified that Bcal3178 regulated target gene expression by directly binding to the promoter DNA regions. We also revealed that Bcal3178 was directly controlled by the AHL system regulator CepR. These results show that Bcal3178 is a new downstream component of the QS signaling network that modulates a subset of genes and functions coregulated by the AHL and BDSF QS systems in B. cenocepacia. IMPORTANCEBurkholderia cenocepacia is an important opportunistic pathogen in humans that utilizes the BDSF and AHL quorum-sensing (QS) systems to regulate biological functions and virulence. We demonstrated here that a new downstream regulator, Bcal3178 of the QS signaling network, controls biofilm formation and protease production. Bcal3178 is a LysR family transcriptional regulator modulated by both the BDSF and AHL QS systems. Furthermore, Bcal3178 controls many target genes, which are regulated by the QS systems in B. cenocepacia. Collectively, our findings depict a novel molecular mechanism with which QS systems regulate some target gene expression and biological functions by modulating the expression level of a LysR family transcriptional regulator in B. cenocepacia.
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18
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Ganesh PS, Vishnupriya S, Vadivelu J, Mariappan V, Vellasamy KM, Shankar EM. Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing-controlled virulence factors, biofilm, and inhibitors. Microbiol Immunol 2020; 64:87-98. [PMID: 31769530 DOI: 10.1111/1348-0421.12762] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/18/2019] [Accepted: 11/21/2019] [Indexed: 12/25/2022]
Abstract
Burkholderia cepacia complex (Bcc) are opportunistic pathogens implicated with nosocomial infections, and high rates of morbidity and mortality, especially in individuals with cystic fibrosis (CF). B. cepacia are naturally resistant to different classes of antibiotics, and can subvert the host innate immune responses by producing quorum sensing (QS) controlled virulence factors and biofilms. It still remains a conundrum as to how exactly the bacterium survives the intracellular environment within the host cells of CF patients and immunocompromised individuals although the bacterium can invade human lung epithelial cells, neutrophils, and murine macrophages. The mechanisms associated with intracellular survival in the airway epithelial cells and the role of QS and virulence factors in B. cepacia infections in cystic fibrosis remain largely unclear. The current review focuses on understanding the role of QS-controlled virulence factors and biofilms, and provides additional impetus to understanding the potentials of QS-inhibitory strategies against B. cepacia.
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Affiliation(s)
- Pitchaipillai Sankar Ganesh
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Sivakumar Vishnupriya
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kumutha M Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Esaki M Shankar
- Division of Infection Biology & Medical Microbiology, Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
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19
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Kaltenpoth M, Flórez LV. Versatile and Dynamic Symbioses Between Insects and Burkholderia Bacteria. ANNUAL REVIEW OF ENTOMOLOGY 2020; 65:145-170. [PMID: 31594411 DOI: 10.1146/annurev-ento-011019-025025] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Symbiotic associations with microorganisms represent major sources of ecological and evolutionary innovations in insects. Multiple insect taxa engage in symbioses with bacteria of the genus Burkholderia, a diverse group that is widespread across different environments and whose members can be mutualistic or pathogenic to plants, fungi, and animals. Burkholderia symbionts provide nutritional benefits and resistance against insecticides to stinkbugs, defend Lagria beetle eggs against pathogenic fungi, and may be involved in nitrogen metabolism in ants. In contrast to many other insect symbioses, the known associations with Burkholderia are characterized by environmental symbiont acquisition or mixed-mode transmission, resulting in interesting ecological and evolutionary dynamics of symbiont strain composition. Insect-Burkholderia symbioses present valuable model systems from which to derive insights into general principles governing symbiotic interactions because they are often experimentally and genetically tractable and span a large fraction of the diversity of functions, localizations, and transmission routes represented in insect symbioses.
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Affiliation(s)
- Martin Kaltenpoth
- Institute of Organismic and Molecular Evolution, Evolutionary Ecology, Johannes Gutenberg University Mainz, 55128 Mainz, Germany; ,
| | - Laura V Flórez
- Institute of Organismic and Molecular Evolution, Evolutionary Ecology, Johannes Gutenberg University Mainz, 55128 Mainz, Germany; ,
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20
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Chitosan and their derivatives: Antibiofilm drugs against pathogenic bacteria. Colloids Surf B Biointerfaces 2020; 185:110627. [DOI: 10.1016/j.colsurfb.2019.110627] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 02/08/2023]
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21
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Tang H, Zhang Y, Hu J, Li Y, Li N, Wang M. Mixture of different Pseudomonas aeruginosa SD-1 strains in the efficient bioaugmentation for synthetic livestock wastewater treatment. CHEMOSPHERE 2019; 237:124455. [PMID: 31376694 DOI: 10.1016/j.chemosphere.2019.124455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 05/30/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Strains selection for inoculation is the key to the successful construction of a bioaugmentation system, a promising strategy for specific pollutant removal. Pseudomonas aeruginosa SD-1 wild-type (WT) strain exhibited high capacity for biofilm formation but low efficiency for nitrate (NO3-) removal. Meanwhile, quorum sensing deficient strain ΔlasR showed excellent efficiency for NO3- removal but poor capability for colonization in activated sludge. The opposite effect of biofilm formation and NO3- removal exist in WT or ΔlasR, which limits the construction of bioaugmentation system of strain SD-1 and its application. To solve this issue, a mixture of WT and ΔlasR (v/v = 1:1) was used to construct a bioaugmentation system. Compared with the inoculation of WT or ΔlasR alone, the mixed inoculation not only was beneficial for activated sludge development but also for pollutant removal. The indicators for activated sludge including the abundance of P. aeruginosa, the sludge volume index and the average particle size in mixed inoculated reactors were close to those of reactors with single and repeated inoculation of WT. The effluent of chemical oxygen demand (COD) and NO3--N were stable at 3.9-22.6 mg L-1 and 0-5.53 mg L-1 after d 3, respectively. This study presents a detailed case on the ecological tradeoff of colonization and pollutant removal of inoculated strains during bioaugmentation. The results provide information on the appropriate conditions for application of P. aeruginosa SD-1 for livestock wastewater treatment and further enrich our ecological understanding of bioaugmentation.
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Affiliation(s)
- Huiming Tang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China
| | - Yunyun Zhang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China
| | - Jingming Hu
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China
| | - Yue Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China
| | - Na Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, PR China
| | - Meizhen Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, PR China.
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22
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Oppy CC, Jebeli L, Kuba M, Oates CV, Strugnell R, Edgington-Mitchell LE, Valvano MA, Hartland EL, Newton HJ, Scott NE. Loss of O-Linked Protein Glycosylation in Burkholderia cenocepacia Impairs Biofilm Formation and Siderophore Activity and Alters Transcriptional Regulators. mSphere 2019; 4:e00660-19. [PMID: 31722994 PMCID: PMC6854043 DOI: 10.1128/msphere.00660-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023] Open
Abstract
O-linked protein glycosylation is a conserved feature of the Burkholderia genus. The addition of the trisaccharide β-Gal-(1,3)-α-GalNAc-(1,3)-β-GalNAc to membrane exported proteins in Burkholderia cenocepacia is required for bacterial fitness and resistance to environmental stress. However, the underlying causes of the defects observed in the absence of glycosylation are unclear. Using proteomics, luciferase reporter assays, and DNA cross-linking, we demonstrate the loss of glycosylation leads to changes in transcriptional regulation of multiple proteins, including the repression of the master quorum CepR/I. These proteomic and transcriptional alterations lead to the abolition of biofilm formation and defects in siderophore activity. Surprisingly, the abundance of most of the known glycosylated proteins did not significantly change in the glycosylation-defective mutants, except for BCAL1086 and BCAL2974, which were found in reduced amounts, suggesting they could be degraded. However, the loss of these two proteins was not responsible for driving the proteomic alterations, biofilm formation, or siderophore activity. Together, our results show that loss of glycosylation in B. cenocepacia results in a global cell reprogramming via alteration of the transcriptional regulatory systems, which cannot be explained by the abundance changes in known B. cenocepacia glycoproteins.IMPORTANCE Protein glycosylation is increasingly recognized as a common posttranslational protein modification in bacterial species. Despite this commonality, our understanding of the role of most glycosylation systems in bacterial physiology and pathogenesis is incomplete. In this work, we investigated the effect of the disruption of O-linked glycosylation in the opportunistic pathogen Burkholderia cenocepacia using a combination of proteomic, molecular, and phenotypic assays. We find that in contrast to recent findings on the N-linked glycosylation systems of Campylobacter jejuni, O-linked glycosylation does not appear to play a role in proteome stabilization of most glycoproteins. Our results reveal that loss of glycosylation in B. cenocepacia strains leads to global proteome and transcriptional changes, including the repression of the quorum-sensing regulator cepR (BCAM1868) gene. These alterations lead to dramatic phenotypic changes in glycosylation-null strains, which are paralleled by both global proteomic and transcriptional alterations, which do not appear to directly result from the loss of glycosylation per se. This research unravels the pleiotropic effects of O-linked glycosylation in B. cenocepacia, demonstrating that its loss does not simply affect the stability of the glycoproteome, but also interferes with transcription and the broader proteome.
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Affiliation(s)
- Cameron C Oppy
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia
| | - Leila Jebeli
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Miku Kuba
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Clare V Oates
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Richard Strugnell
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Laura E Edgington-Mitchell
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Department of Oral and Maxillofacial Surgery, New York University College of Dentistry, Bluestone Center for Clinical Research, New York, New York, USA
| | - Miguel A Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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Disruption of Quorum Sensing and Virulence in Burkholderia cenocepacia by a Structural Analogue of the cis-2-Dodecenoic Acid Signal. Appl Environ Microbiol 2019; 85:AEM.00105-19. [PMID: 30770405 DOI: 10.1128/aem.00105-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 02/07/2019] [Indexed: 12/17/2022] Open
Abstract
Quorum sensing (QS) signals are widely used by bacterial pathogens to control biological functions and virulence in response to changes in cell population densities. Burkholderia cenocepacia employs a molecular mechanism in which the cis-2-dodecenoic acid (named Burkholderia diffusible signal factor [BDSF]) QS system regulates N-acyl homoserine lactone (AHL) signal production and virulence by modulating intracellular levels of cyclic diguanosine monophosphate (c-di-GMP). Thus, inhibition of BDSF signaling may offer a non-antibiotic-based therapeutic strategy against BDSF-regulated bacterial infections. In this study, we report the synthesis of small-molecule mimics of the BDSF signal and evaluate their ability to inhibit BDSF QS signaling in B. cenocepacia A novel structural analogue of BDSF, 14-Me-C16:Δ2 (cis-14-methylpentadec-2-enoic acid), was observed to inhibit BDSF production and impair BDSF-regulated phenotypes in B. cenocepacia, including motility, biofilm formation, and virulence, while it did not inhibit the growth rate of this pathogen. 14-Me-C16:Δ2 also reduced AHL signal production. Genetic and biochemical analyses showed that 14-Me-C16:Δ2 inhibited the production of the BDSF and AHL signals by decreasing the expression of their synthase-encoding genes. Notably, 14-Me-C16:Δ2 attenuated BDSF-regulated phenotypes in various Burkholderia species. These findings suggest that 14-Me-C16:Δ2 could potentially be developed as a new therapeutic agent against pathogenic Burkholderia species by interfering with their QS signaling.IMPORTANCE Burkholderia cenocepacia is an important opportunistic pathogen which can cause life-threatening infections in susceptible individuals, particularly in cystic fibrosis and immunocompromised patients. It usually employs two types of quorum sensing (QS) systems, including the cis-2-dodecenoic acid (BDSF) system and N-acyl homoserine lactone (AHL) system, to regulate virulence. In this study, we have designed and identified an unsaturated fatty acid compound (cis-14-methylpentadec-2-enoic acid [14-Me-C16:Δ2]) that is capable of interfering with B. cenocepacia QS signaling and virulence. We demonstrate that 14-Me-C16:Δ2 reduced BDSF and AHL signal production in B. cenocepacia It also impaired QS-regulated phenotypes in various Burkholderia species. These results suggest that 14-Me-C16:Δ2 could interfere with QS signaling in many Burkholderia species and might be developed as a new antibacterial agent.
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24
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Exopolysaccharides produced by Pandoraea shows emulsifying and anti-biofilm activities. JOURNAL OF POLYMER RESEARCH 2019. [DOI: 10.1007/s10965-019-1737-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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25
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Differential Gene Expression Patterns of Yersinia pestis and Yersinia pseudotuberculosis during Infection and Biofilm Formation in the Flea Digestive Tract. mSystems 2019; 4:mSystems00217-18. [PMID: 30801031 PMCID: PMC6381227 DOI: 10.1128/msystems.00217-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/27/2019] [Indexed: 01/01/2023] Open
Abstract
Yersinia pestis, the etiologic agent of plague, emerged as a fleaborne pathogen only within the last 6,000 years. Just five simple genetic changes in the Yersinia pseudotuberculosis progenitor, which served to eliminate toxicity to fleas and to enhance survival and biofilm formation in the flea digestive tract, were key to the transition to the arthropodborne transmission route. To gain a deeper understanding of the genetic basis for the development of a transmissible biofilm infection in the flea foregut, we evaluated additional gene differences and performed in vivo transcriptional profiling of Y. pestis, a Y. pseudotuberculosis wild-type strain (unable to form biofilm in the flea foregut), and a Y. pseudotuberculosis mutant strain (able to produce foregut-blocking biofilm in fleas) recovered from fleas 1 day and 14 days after an infectious blood meal. Surprisingly, the Y. pseudotuberculosis mutations that increased c-di-GMP levels and enabled biofilm development in the flea did not change the expression levels of the hms genes responsible for the synthesis and export of the extracellular polysaccharide matrix required for mature biofilm formation. The Y. pseudotuberculosis mutant uniquely expressed much higher levels of Yersinia type VI secretion system 4 (T6SS-4) in the flea, and this locus was required for flea blockage by Y. pseudotuberculosis but not for blockage by Y. pestis. Significant differences between the two species in expression of several metabolism genes, the Psa fimbrial genes, quorum sensing-related genes, transcription regulation genes, and stress response genes were evident during flea infection. IMPORTANCE Y. pestis emerged as a highly virulent, arthropod-transmitted pathogen on the basis of relatively few and discrete genetic changes from Y. pseudotuberculosis. Parallel comparisons of the in vitro and in vivo transcriptomes of Y. pestis and two Y. pseudotuberculosis variants that produce a nontransmissible infection and a transmissible infection of the flea vector, respectively, provided insights into how Y. pestis has adapted to life in its flea vector and point to evolutionary changes in the regulation of metabolic and biofilm development pathways in these two closely related species.
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Mechanisms of Bacterial Tolerance and Persistence in the Gastrointestinal and Respiratory Environments. Clin Microbiol Rev 2018; 31:31/4/e00023-18. [PMID: 30068737 DOI: 10.1128/cmr.00023-18] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as Escherichia coli, Salmonella spp., Vibrio spp., Helicobacter spp., Campylobacter jejuni, Enterococcus spp., Shigella spp., Yersinia spp., and Clostridium difficile, all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cenocepacia, and Mycobacterium tuberculosis Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.
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Shehata HR, Raizada MN. A Burkholderia endophyte of the ancient maize landrace Chapalote utilizes c-di-GMP-dependent and independent signaling to suppress diverse plant fungal pathogen targets. FEMS Microbiol Lett 2018; 364:3898815. [PMID: 28679171 DOI: 10.1093/femsle/fnx138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 06/29/2017] [Indexed: 12/19/2022] Open
Abstract
Chapalote is a maize (corn) landrace grown continuously by subsistence farmers in the Americas since 1000 BC, valued in part for its broad-spectrum pathogen resistance. Previously, we showed that Chapalote possesses a bacterial endophyte, Burkholderia gladioli strain 3A12, which suppresses growth of Sclerotinia homoeocarpa, a fungal pathogen of a maize relative, used as a model system. Ten mutants that lost the anti-pathogen activities were identified, corresponding to five genes. However, S. homoeocarpa is not a known maize pathogen; hence, the relevance of these anti-fungal mechanisms to its ancient host has not been clear. Here, the strain 3A12 mutants were tested against a known pathogen of maize and many crops, Rhizoctonia solani. Microscopy established that wild-type 3A12 swarms towards, and attaches onto, the pathogen, forming microcolonies, resulting in hyphal cleavage. Analysis of the mutants revealed that 3A12 uses common downstream gene products (e.g. fungicides) to suppress the growth of both S. homoeocarpa and R. solani, but apparently different upstream regulatory machinery, with the former, but not latter pathogen, requiring YajQ, a receptor for the secondary messenger c-di-GMP. We conclude that B. gladioli strain 3A12, an endophyte of an ancient maize, employs both c-di-GMP-dependent and independent signaling to target diverse fungal pathogens.
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Affiliation(s)
- Hanan R Shehata
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada.,Department of Microbiology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Manish N Raizada
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
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28
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Cui C, Yang C, Song S, Fu S, Sun X, Yang L, He F, Zhang LH, Zhang Y, Deng Y. A novel two-component system modulates quorum sensing and pathogenicity in Burkholderia cenocepacia. Mol Microbiol 2018; 108:32-44. [PMID: 29363827 DOI: 10.1111/mmi.13915] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/11/2018] [Accepted: 01/21/2018] [Indexed: 01/01/2023]
Abstract
Quorum sensing (QS) is widely utilized by bacterial pathogens to regulate biological functions and pathogenicity. Recent evidence has shown that QS is subject to regulatory cascades, especially two-component systems that often respond to environmental stimulation. At least two different types of QS systems regulate pathogenesis in Burkholderia cenocepacia. However, it remains unclear how this bacterial pathogen controls these QS systems. Here, we demonstrate a novel two-component system RqpSR (Regulating Quorum sensing and Pathogenicity), which plays an important role in modulating QS and pathogenesis in B. cenocepacia. We demonstrate strong protein-protein binding affinity between RqpS and RqpR. Mutations in rqpS and rqpR exerted overlapping effects on B. cenocepacia transcriptomes and phenotypes, including motility, biofilm formation and virulence. In trans expression of rqpR rescued the defective phenotypes in the rqpS mutant. RqpR controls target gene expression by direct binding to DNA promoters, including the cis-2-dodecenoic acid (BDSF) and N-acylhomoserine lactone (AHL) signal synthase gene promoters. These findings suggest that the RqpSR system strongly modulates physiology by forming a complicated hierarchy with QS systems. This type of two-component system appears to be widely distributed and coexists with the BDSF QS system in various bacterial species.
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Affiliation(s)
- Chaoyu Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Chunxi Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Shihao Song
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Shuna Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Xiuyun Sun
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551, Singapore
| | - Fei He
- Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Lian-Hui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
| | - Yongliang Zhang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Yinyue Deng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.,Guangdong Innovative Research Team of Sociomicrobiology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China
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Slachmuylders L, Van Acker H, Brackman G, Sass A, Van Nieuwerburgh F, Coenye T. Elucidation of the mechanism behind the potentiating activity of baicalin against Burkholderia cenocepacia biofilms. PLoS One 2018; 13:e0190533. [PMID: 29293658 PMCID: PMC5749847 DOI: 10.1371/journal.pone.0190533] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/16/2017] [Indexed: 11/19/2022] Open
Abstract
Reduced antimicrobial susceptibility due to resistance and tolerance has become a serious threat to human health. An approach to overcome this reduced susceptibility is the use of antibiotic adjuvants, also known as potentiators. These are compounds that have little or no antibacterial effect on their own but increase the susceptibility of bacterial cells towards antimicrobial agents. Baicalin hydrate, previously described as a quorum sensing inhibitor, is such a potentiator that increases the susceptibility of Burkholderia cenocepacia J2315 biofilms towards tobramycin. The goal of the present study is to elucidate the molecular mechanisms behind the potentiating activity of baicalin hydrate and related flavonoids. We first determined the effect of multiple flavonoids on susceptibility of B. cenocepacia J2315 towards tobramycin. Increased antibiotic susceptibility was most pronounced in combination with apigenin 7-O-glucoside and baicalin hydrate. For baicalin hydrate, also other B. cepacia complex strains and other antibiotics were tested. The potentiating effect was only observed for aminoglycosides and was both strain- and aminoglycoside-dependent. Subsequently, gene expression was compared between baicalin hydrate treated and untreated cells, in the presence and absence of tobramycin. This revealed that baicalin hydrate affected cellular respiration, resulting in increased reactive oxygen species production in the presence of tobramycin. We subsequently showed that baicalin hydrate has an impact on oxidative stress via several pathways including oxidative phosphorylation, glucarate metabolism and by modulating biosynthesis of putrescine. Furthermore, our data strongly suggest that the influence of baicalin hydrate on oxidative stress is unrelated to quorum sensing. Our data indicate that the potentiating effect of baicalin hydrate is due to modulating the oxidative stress response, which in turn leads to increased tobramycin-mediated killing.
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Affiliation(s)
- Lisa Slachmuylders
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Heleen Van Acker
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Gilles Brackman
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | | | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
- * E-mail:
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Identification of AHL- and BDSF-Controlled Proteins in Burkholderia cenocepacia by Proteomics. Methods Mol Biol 2018; 1673:193-202. [PMID: 29130174 DOI: 10.1007/978-1-4939-7309-5_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We used comparative proteome analysis to determine the target genes of the two quorum sensing (QS) circuits in the opportunistic pathogen Burkholderia cenocepacia: the N-acyl homoserine lactone (AHL)-based CepIR system and the BDSF (B urkholderia diffusible signal factor, cis-2-dodecenoic acid)-based RpfFR system. In this book chapter, we focus on the description of the practical procedure we currently use in the laboratory to perform a sensitive GeLC-MS/MS shotgun proteomics experiment; we also briefly describe the downstream bioinformatic data analysis.
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Burkholderia cenocepacia integrates cis-2-dodecenoic acid and cyclic dimeric guanosine monophosphate signals to control virulence. Proc Natl Acad Sci U S A 2017; 114:13006-13011. [PMID: 29158389 DOI: 10.1073/pnas.1709048114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Quorum sensing (QS) signals are used by bacteria to regulate biological functions in response to cell population densities. Cyclic diguanosine monophosphate (c-di-GMP) regulates cell functions in response to diverse environmental chemical and physical signals that bacteria perceive. In Burkholderia cenocepacia, the QS signal receptor RpfR degrades intracellular c-di-GMP when it senses the QS signal cis-2-dodecenoic acid, also called Burkholderia diffusible signal factor (BDSF), as a proxy for high cell density. However, it was unclear how this resulted in control of BDSF-regulated phenotypes. Here, we found that RpfR forms a complex with a regulator named GtrR (BCAL1536) to enhance its binding to target gene promoters under circumstances where the BDSF signal binds to RpfR to stimulate its c-di-GMP phosphodiesterase activity. In the absence of BDSF, c-di-GMP binds to the RpfR-GtrR complex and inhibits its ability to control gene expression. Mutations in rpfR and gtrR had overlapping effects on both the B. cenocepacia transcriptome and BDSF-regulated phenotypes, including motility, biofilm formation, and virulence. These results show that RpfR is a QS signal receptor that also functions as a c-di-GMP sensor. This protein thus allows B. cenocepacia to integrate information about its physical and chemical surroundings as well as its population density to control diverse biological functions including virulence. This type of QS system appears to be widely distributed in beta and gamma proteobacteria.
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32
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Jung HI, Kim YJ, Lee YJ, Lee HS, Lee JK, Kim SK. Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation. J Microbiol 2017; 55:800-808. [PMID: 28956352 DOI: 10.1007/s12275-017-7374-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/14/2017] [Accepted: 09/17/2017] [Indexed: 12/11/2022]
Abstract
Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.
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Affiliation(s)
- Hae-In Jung
- Department of Animal Science and Technology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Yun-Jung Kim
- Department of Animal Science and Technology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Yun-Jung Lee
- Department of Animal Science and Technology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee-Soo Lee
- National Veterinary Research and Quarantine Service, Anyang, 14033, Republic of Korea
| | - Jung-Kee Lee
- Department of Life Science and Genetic Engineering, Paichai University, Daejeon, 35345, Republic of Korea
| | - Soo-Ki Kim
- Department of Animal Science and Technology, Konkuk University, Seoul, 05029, Republic of Korea.
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Abstract
Candida species are the most common infectious fungal species in humans; out of the approximately 150 known species, Candida albicans is the leading pathogenic species, largely affecting immunocompromised individuals. Apart from its role as the primary etiology for various types of candidiasis, C. albicans is known to contribute to polymicrobial infections. Polymicrobial interactions, particularly between C. albicans and bacterial species, have gained recent interest in which polymicrobial biofilm virulence mechanisms have been studied including adhesion, invasion, quorum sensing, and development of antimicrobial resistance. These trans-kingdom interactions, either synergistic or antagonistic, may help modulate the virulence and pathogenicity of both Candida and bacteria while uniquely impacting the pathogen-host immune response. As antibiotic and antifungal resistance increases, there is a great need to explore the intermicrobial cross-talk with a focus on the treatment of Candida-associated polymicrobial infections. This article explores the current literature on the interactions between Candida and clinically important bacteria and evaluates these interactions in the context of pathogenesis, diagnosis, and disease management.
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Schuster M, Sexton DJ, Hense BA. Why Quorum Sensing Controls Private Goods. Front Microbiol 2017; 8:885. [PMID: 28579979 PMCID: PMC5437708 DOI: 10.3389/fmicb.2017.00885] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/02/2017] [Indexed: 12/22/2022] Open
Abstract
Cell-cell communication, also termed quorum sensing (QS), is a widespread process that coordinates gene expression in bacterial populations. The generally accepted view is that QS optimizes the cell density-dependent benefit attained from cooperative behaviors, often in the form of secreted products referred to as "public goods." This view is challenged by an increasing number of cell-associated products or "private goods" reported to be under QS-control for which a collective benefit is not apparent. A prominent example is nucleoside hydrolase from Pseudomonas aeruginosa, a periplasmic enzyme that catabolizes adenosine. Several recent studies have shown that private goods can function to stabilize cooperation by co-regulated public goods, seemingly explaining their control by QS. Here we argue that this property is a by-product of selection for other benefits rather than an adaptation. Emphasizing ecophysiological context, we propose alternative explanations for the QS control of private goods. We suggest that the benefit attained from private goods is associated with high cell density, either because a relevant ecological condition correlates with density, or because the private good is, directly or indirectly, involved in cooperative behavior. Our analysis helps guide a systems approach to QS, with implications for antivirulence drug design and synthetic biology.
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Affiliation(s)
- Martin Schuster
- Department of Microbiology, Oregon State UniversityCorvallis, OR, United States
| | - D Joseph Sexton
- Department of Microbiology, Oregon State UniversityCorvallis, OR, United States
| | - Burkhard A Hense
- Institute of Computational Biology, Helmholtz Zentrum MünchenNeuherberg, Germany
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Burkholderia cepacia Complex Regulation of Virulence Gene Expression: A Review. Genes (Basel) 2017; 8:genes8010043. [PMID: 28106859 PMCID: PMC5295037 DOI: 10.3390/genes8010043] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/11/2017] [Accepted: 01/12/2017] [Indexed: 12/31/2022] Open
Abstract
Burkholderia cepacia complex (Bcc) bacteria emerged as opportunistic pathogens in cystic fibrosis and immunocompromised patients. Their eradication is very difficult due to the high level of intrinsic resistance to clinically relevant antibiotics. Bcc bacteria have large and complex genomes, composed of two to four replicons, with variable numbers of insertion sequences. The complexity of Bcc genomes confers a high genomic plasticity to these bacteria, allowing their adaptation and survival to diverse habitats, including the human host. In this work, we review results from recent studies using omics approaches to elucidate in vivo adaptive strategies and virulence gene regulation expression of Bcc bacteria when infecting the human host or subject to conditions mimicking the stressful environment of the cystic fibrosis lung.
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36
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Shehata HR, Ettinger CL, Eisen JA, Raizada MN. Genes Required for the Anti-fungal Activity of a Bacterial Endophyte Isolated from a Corn Landrace Grown Continuously by Subsistence Farmers Since 1000 BC. Front Microbiol 2016; 7:1548. [PMID: 27757101 PMCID: PMC5047915 DOI: 10.3389/fmicb.2016.01548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022] Open
Abstract
Endophytes are microbes that inhabit internal plant tissues without causing disease. Some endophytes are known to combat pathogens. The corn (maize) landrace Chapalote has been grown continuously by subsistence farmers in the Americas since 1000 BC, without the use of fungicides, and the crop remains highly valued by farmers, in part for its natural tolerance to pests. We hypothesized that the pathogen tolerance of Chapalote may, in part, be due to assistance from its endophytes. We previously identified a bacterial endophyte from Chapalote seeds, Burkholderia gladioli strain 3A12, for its ability to combat a diversity of crop pathogens, including Sclerotinia homoeocarpa, the most important fungal disease of creeping bentgrass, a relative of maize used here as a model system. Strain 3A12 represents a unique opportunity to understand the anti-fungal activities of an endophyte associated with a crop variety grown by subsistence farmers since ancient times. Here, microscopy combined with Tn5-mutagenesis demonstrates that the anti-fungal mode of action of 3A12 involves flagella-dependent swarming toward its pathogen target, attachment and biofilm-mediated microcolony formation. The mutant screen revealed that YajQ, a receptor for the secondary messenger c-di-GMP, is a critical signaling system that mediates this endophytic mobility-based defense for its host. Microbes from the traditional seeds of farmers may represent a new frontier in elucidating host-microbe mutualistic interactions.
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Affiliation(s)
- Hanan R. Shehata
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
- Department of Microbiology, School of Pharmacy, Mansoura UniversityMansoura, Egypt
| | - Cassandra L. Ettinger
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
| | - Jonathan A. Eisen
- Genome Center, University of California Davis, DavisCA, USA
- Department of Evolution and Ecology, University of California Davis, DavisCA, USA
- Department of Medical Microbiology and Immunology, University of California Davis, DavisCA, USA
| | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, GuelphON, Canada
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Quorum Sensing Influences Burkholderia thailandensis Biofilm Development and Matrix Production. J Bacteriol 2016; 198:2643-50. [PMID: 27068594 PMCID: PMC5019063 DOI: 10.1128/jb.00047-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/01/2016] [Indexed: 12/27/2022] Open
Abstract
UNLABELLED Members of the genus Burkholderia are known to be adept at biofilm formation, which presumably assists in the survival of these organisms in the environment and the host. Biofilm formation has been linked to quorum sensing (QS) in several bacterial species. In this study, we characterized Burkholderia thailandensis biofilm development under flow conditions and sought to determine whether QS contributes to this process. B. thailandensis biofilm formation exhibited an unusual pattern: the cells formed small aggregates and then proceeded to produce mature biofilms characterized by "dome" structures filled with biofilm matrix material. We showed that this process was dependent on QS. B. thailandensis has three acyl-homoserine lactone (AHL) QS systems (QS-1, QS-2, and QS-3). An AHL-negative strain produced biofilms consisting of cell aggregates but lacking the matrix-filled dome structures. This phenotype was rescued via exogenous addition of the three AHL signals. Of the three B. thailandensis QS systems, we show that QS-1 is required for proper biofilm development, since a btaR1 mutant, which is defective in QS-1 regulation, forms biofilms without these dome structures. Furthermore, our data show that the wild-type biofilm biomass, as well as the material inside the domes, stains with a fucose-binding lectin. The btaR1 mutant biofilms, however, are negative for fucose staining. This suggests that the QS-1 system regulates the production of a fucose-containing exopolysaccharide in wild-type biofilms. Finally, we present data showing that QS ability during biofilm development produces a biofilm that is resistant to dispersion under stress conditions. IMPORTANCE The saprophyte Burkholderia thailandensis is a close relative of the pathogenic bacterium Burkholderia pseudomallei, the causative agent of melioidosis, which is contracted from its environmental reservoir. Since most bacteria in the environment reside in biofilms, B. thailandensis is an ideal model organism for investigating questions in Burkholderia physiology. In this study, we characterized B. thailandensis biofilm development and sought to determine if quorum sensing (QS) contributes to this process. Our work shows that B. thailandensis produces biofilms with unusual dome structures under flow conditions. Our findings suggest that these dome structures are filled with a QS-regulated, fucose-containing exopolysaccharide that may be involved in the resilience of B. thailandensis biofilms against changes in the nutritional environment.
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Discovery of new diketopiperazines inhibiting Burkholderia cenocepacia quorum sensing in vitro and in vivo. Sci Rep 2016; 6:32487. [PMID: 27580679 PMCID: PMC5007513 DOI: 10.1038/srep32487] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/08/2016] [Indexed: 02/08/2023] Open
Abstract
Burkholderia cenocepacia, an opportunistic respiratory pathogen particularly relevant for cystic fibrosis patients, is difficult to eradicate due to its high level of resistance to most clinically relevant antimicrobials. Consequently, the discovery of new antimicrobials as well as molecules capable of inhibiting its virulence is mandatory. In this regard quorum sensing (QS) represents a good target for anti-virulence therapies, as it has been linked to biofilm formation and is important for the production of several virulence factors, including proteases and siderophores. Here, we report the discovery of new diketopiperazine inhibitors of the B. cenocepacia acyl homoserine lactone synthase CepI, and report their anti-virulence properties. Out of ten different compounds assayed against recombinant CepI, four were effective inhibitors, with IC50 values in the micromolar range. The best compounds interfered with protease and siderophore production, as well as with biofilm formation, and showed good in vivo activity in a Caenorhabditis elegans infection model. These molecules were also tested in human cells and showed very low toxicity. Therefore, they could be considered for in vivo combined treatments with established or novel antimicrobials, to improve the current therapeutic strategies against B. cenocepacia.
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Spadaro F, Scoffone VC, Chiarelli LR, Fumagalli M, Buroni S, Riccardi G, Forneris F. The Crystal Structure of Burkholderia cenocepacia DfsA Provides Insights into Substrate Recognition and Quorum Sensing Fatty Acid Biosynthesis. Biochemistry 2016; 55:3241-50. [PMID: 27198181 DOI: 10.1021/acs.biochem.6b00178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Burkholderia cenocepacia is a major concern among respiratory tract infections in cystic fibrosis patients. This pathogen is particularly difficult to treat because of its high level of resistance to the clinically relevant antimicrobial agents. In B. cenocepacia, the quorum sensing cell-cell communication system is involved in different processes that are important for bacterial virulence, such as biofilm formation and protease and siderophore production. Targeting the enzymes involved in this process represents a promising therapeutic approach. With the aim of finding effective quorum sensing inhibitors, we have determined the three-dimensional structure of B. cenocepacia diffusible factor synthase A, DfsA. This bifunctional crotonase (dehydratase/thioesterase) produces the characteristic quorum sensing molecule of B. cenocepacia, cis-2-dodecenoic acid or BDSF, starting from 3-hydroxydodecanoyl-acyl carrier protein. Unexpectedly, the crystal structure revealed the presence of a lipid molecule in the catalytic site of the enzyme, which was identified as dodecanoic acid. Our biochemical characterization shows that DfsA is able to use dodecanoyl-acyl carrier protein as a substrate, demonstrating that dodecanoic acid, the product of this reaction, is released very slowly from the DfsA active site, therefore acting as a DfsA inhibitor. This molecule shows an unprecedented conformational arrangement inside the DfsA active site. In contrast with previous hypotheses, our data illustrate how DfsA and closely related homologous enzymes can recognize long hydrophobic substrates without large conformational changes or assistance by additional regulator molecules. The elucidation of the substrate binding mode in DfsA provides the starting point for structure-based drug discovery studies targeting B. cenocepacia quorum sensing-assisted virulence.
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Affiliation(s)
- Francesca Spadaro
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Viola C Scoffone
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Laurent R Chiarelli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Marco Fumagalli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Giovanna Riccardi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Federico Forneris
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
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Pradenas GA, Ross BN, Torres AG. Burkholderia cepacia Complex Vaccines: Where Do We Go from here? Vaccines (Basel) 2016; 4:vaccines4020010. [PMID: 27092530 PMCID: PMC4931627 DOI: 10.3390/vaccines4020010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 01/15/2023] Open
Abstract
Burkholderia comprises a wide variety of environmental Gram-negative bacteria. Burkholderia cepacia complex (Bcc) includes several Burkholderia species that pose a health hazard as they are able to cause respiratory infections in patients with chronic granulomatous disease and cystic fibrosis. Due to the intrinsic resistance to a wide array of antibiotics and naturally occurring immune evasion strategies, treatment of Bcc infections often proves to be unsuccessful. To date, limited work related to vaccine development has been performed for Bcc pathogens. In this review, we have gathered key aspects of Bcc research that have been reported in recent years related to vaccine efforts, virulence, immune responses, and animal models, and use this information to inform the research community of areas of opportunity toward development of a viable Bcc vaccine.
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Affiliation(s)
- Gonzalo A Pradenas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Brittany N Ross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Veselova MA, Romanova YM, Lipasova VA, Koksharova OA, Zaitseva YV, Chernukha MU, Gintsburg AL, Khmel IA. The effect of mutation in the clpX gene on the synthesis of N-acyl-homoserine lactones and other properties of Burkholderia cenocepacia 370. Microbiol Res 2016; 186-187:90-8. [PMID: 27242147 DOI: 10.1016/j.micres.2016.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/24/2016] [Accepted: 03/31/2016] [Indexed: 10/22/2022]
Abstract
In order to study the regulation of N-acyl-homoserine lactones synthesis (AHLs, the signal molecules of Quorum Sensing regulation) in Burkholderia cenocepacia strain 370 we obtained mutants with increased AHL production. One of the mutants, named BC-B6, was obtained by TnMod-RKm(r) plasposon mutagenesis. The plasposon insertion was located within the clpX gene encoding the ATPase subunit ClpX of the ClpXP protease. The mutation reduced bacterial virulence in mice intranasal infection. The results of proteomic analysis demonstrated that the expression of at least 19 proteins differed not less than 2-fold between the parental and mutant strains. 18 of the proteins were upregulated in the mutant, and one protein was downregulated. The proteins included those that involved in protein synthesis and modification, in energy production, in general metabolism, in transport and regulation. To check the effect of the clpX mutation on the AHL synthesis, a mutant with inactivated clpX gene (BC-clpX:Km(r)) was constructed by gene replacement method. This mutant also exhibited increased AHLs production. A swarming motility of both mutants was reduced compared to the original strain. Thus, the obtained results show that the clpX gene was involved in the regulation of AHL production and a number of cellular processes in B. cenocepacia 370.
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Affiliation(s)
- M A Veselova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square 2, Moscow 123182, Russia
| | - Yu M Romanova
- The Gamaleya Scientific Research Centre of Epidemiology and Microbiology, Gamaleya Str. 18, Moscow 123098, Russia
| | - V A Lipasova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square 2, Moscow 123182, Russia
| | - O A Koksharova
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square 2, Moscow 123182, Russia; M.V. Lomonosov Moscow State University, A.N. Belozersky Institute of Physico-Chemical Biology, Leninskie Gory 1-40, Moscow 119991, Russia
| | - Yu V Zaitseva
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square 2, Moscow 123182, Russia
| | - M U Chernukha
- The Gamaleya Scientific Research Centre of Epidemiology and Microbiology, Gamaleya Str. 18, Moscow 123098, Russia
| | - A L Gintsburg
- The Gamaleya Scientific Research Centre of Epidemiology and Microbiology, Gamaleya Str. 18, Moscow 123098, Russia
| | - I A Khmel
- Institute of Molecular Genetics, Russian Academy of Sciences, Kurchatov Square 2, Moscow 123182, Russia.
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Beshr G, Sommer R, Hauck D, Siebert DCB, Hofmann A, Imberty A, Titz A. Development of a competitive binding assay for the Burkholderia cenocepacia lectin BC2L-A and structure activity relationship of natural and synthetic inhibitors. MEDCHEMCOMM 2016. [DOI: 10.1039/c5md00557d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Burkholderia cenocepacia is an opportunistic Gram-negative pathogen and especially hazardous for cystic fibrosis patients.
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Affiliation(s)
- Ghamdan Beshr
- Chemical Biology of Carbohydrates
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)
- D-66123 Saarbrücken
- Germany
- Deutsches Zentrum für Infektionsforschung (DZIF)
| | - Roman Sommer
- Chemical Biology of Carbohydrates
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)
- D-66123 Saarbrücken
- Germany
- Deutsches Zentrum für Infektionsforschung (DZIF)
| | - Dirk Hauck
- Chemical Biology of Carbohydrates
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)
- D-66123 Saarbrücken
- Germany
- Deutsches Zentrum für Infektionsforschung (DZIF)
| | - David Chan Bodin Siebert
- Chemical Biology of Carbohydrates
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)
- D-66123 Saarbrücken
- Germany
- Deutsches Zentrum für Infektionsforschung (DZIF)
| | - Anna Hofmann
- Department of Chemistry and Graduate School Chemical Biology
- University of Konstanz
- D-78457 Konstanz
- Germany
| | - Anne Imberty
- Centre de Recherches sur les Macromolécules Végétales (CERMAV)-CNRS and Université Grenoble Alpes
- F-38041 Grenoble
- France
| | - Alexander Titz
- Chemical Biology of Carbohydrates
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)
- D-66123 Saarbrücken
- Germany
- Deutsches Zentrum für Infektionsforschung (DZIF)
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Plyuta VA, Lipasova VA, Koksharova OA, Veselova MA, Kuznetsov AE, Khmel IA. The effect of introduction of the Heterologous gene encoding the N-acyl-homoserine lactonase (aiiA) on the properties of Burkholderia cenocepacia 370. RUSS J GENET+ 2015. [DOI: 10.1134/s1022795415080062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Emerenini BO, Hense BA, Kuttler C, Eberl HJ. A Mathematical Model of Quorum Sensing Induced Biofilm Detachment. PLoS One 2015; 10:e0132385. [PMID: 26197231 PMCID: PMC4511412 DOI: 10.1371/journal.pone.0132385] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 06/12/2015] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Cell dispersal (or detachment) is part of the developmental cycle of microbial biofilms. It can be externally or internally induced, and manifests itself in discrete sloughing events, whereby many cells disperse in an instance, or in continuous slower dispersal of single cells. One suggested trigger of cell dispersal is quorum sensing, a cell-cell communication mechanism used to coordinate gene expression and behavior in groups based on population densities. METHOD To better understand the interplay of colony growth and cell dispersal, we develop a dynamic, spatially extended mathematical model that includes biofilm growth, production of quorum sensing molecules, cell dispersal triggered by quorum sensing molecules, and re-attachment of cells. This is a highly nonlinear system of diffusion-reaction equations that we study in computer simulations. RESULTS Our results show that quorum sensing induced cell dispersal can be an efficient mechanism for bacteria to control the size of a biofilm colony, and at the same time enhance its downstream colonization potential. In fact we find that over the lifetime of a biofilm colony the majority of cells produced are lost into the aqueous phase, supporting the notion of biofilms as cell nurseries. We find that a single quorum sensing based mechanism can explain both, discrete dispersal events and continuous shedding of cells from a colony. Moreover, quorum sensing induced cell dispersal affects the structure and architecture of the biofilm, for example it might lead to the formation of hollow inner regions in a biofilm colony.
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Affiliation(s)
| | - Burkhard A. Hense
- Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Christina Kuttler
- Zentrum Mathematik, Technische Universität München, Neuherberg, Germany
| | - Hermann J. Eberl
- Dept. Mathematics and Statistics, University of Guelph, Guelph, ON, Canada
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Castillo-Juárez I, Maeda T, Mandujano-Tinoco EA, Tomás M, Pérez-Eretza B, García-Contreras SJ, Wood TK, García-Contreras R. Role of quorum sensing in bacterial infections. World J Clin Cases 2015; 3:575-598. [PMID: 26244150 PMCID: PMC4517333 DOI: 10.12998/wjcc.v3.i7.575] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/30/2014] [Accepted: 04/20/2015] [Indexed: 02/05/2023] Open
Abstract
Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed.
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In-Frame and Unmarked Gene Deletions in Burkholderia cenocepacia via an Allelic Exchange System Compatible with Gateway Technology. Appl Environ Microbiol 2015; 81:3623-30. [PMID: 25795676 DOI: 10.1128/aem.03909-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 03/11/2015] [Indexed: 02/04/2023] Open
Abstract
Burkholderia cenocepacia is an emerging opportunistic pathogen causing life-threatening infections in immunocompromised individuals and in patients with cystic fibrosis, which are often difficult, if not impossible, to treat. Understanding the genetic basis of virulence in this emerging pathogen is important for the development of novel treatment regimes. Generation of deletion mutations in genes predicted to encode virulence determinants is fundamental to investigating the mechanisms of pathogenesis. However, there is a lack of appropriate selectable and counterselectable markers for use in B. cenocepacia, making its genetic manipulation problematic. Here we describe a Gateway-compatible allelic exchange system based on the counterselectable pheS gene and the I-SceI homing endonuclease. This system provides efficiency in cloning homology regions of target genes and allows the generation of precise and unmarked gene deletions in B. cenocepacia. As a proof of concept, we demonstrate its utility by deleting the Bcam1349 gene, encoding a cyclic di-GMP (c-di-GMP)-responsive regulator protein important for biofilm formation.
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Abstract
SUMMARY Autoinduction (AI), the response to self-produced chemical signals, is widespread in the bacterial world. This process controls vastly different target functions, such as luminescence, nutrient acquisition, and biofilm formation, in different ways and integrates additional environmental and physiological cues. This diversity raises questions about unifying principles that underlie all AI systems. Here, we suggest that such core principles exist. We argue that the general purpose of AI systems is the homeostatic control of costly cooperative behaviors, including, but not limited to, secreted public goods. First, costly behaviors require preassessment of their efficiency by cheaper AI signals, which we encapsulate in a hybrid "push-pull" model. The "push" factors cell density, diffusion, and spatial clustering determine when a behavior becomes effective. The relative importance of each factor depends on each species' individual ecological context and life history. In turn, "pull" factors, often stress cues that reduce the activation threshold, determine the cellular demand for the target behavior. Second, control is homeostatic because AI systems, either themselves or through accessory mechanisms, not only initiate but also maintain the efficiency of target behaviors. Third, AI-controlled behaviors, even seemingly noncooperative ones, are generally cooperative in nature, when interpreted in the appropriate ecological context. The escape of individual cells from biofilms, for example, may be viewed as an altruistic behavior that increases the fitness of the resident population by reducing starvation stress. The framework proposed here helps appropriately categorize AI-controlled behaviors and allows for a deeper understanding of their ecological and evolutionary functions.
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Affiliation(s)
- Burkhard A Hense
- Institute for Computational Biology, Helmholtz Zentrum München, Neuherberg/Munich, Germany
| | - Martin Schuster
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
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Gutiérrez-Barranquero JA, Reen FJ, McCarthy RR, O'Gara F. Deciphering the role of coumarin as a novel quorum sensing inhibitor suppressing virulence phenotypes in bacterial pathogens. Appl Microbiol Biotechnol 2015; 99:3303-16. [PMID: 25672848 DOI: 10.1007/s00253-015-6436-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/06/2015] [Accepted: 01/25/2015] [Indexed: 12/31/2022]
Abstract
The rapid unchecked rise in antibiotic resistance over the last few decades has led to an increased focus on the need for alternative therapeutic strategies for the treatment and clinical management of microbial infections. In particular, small molecules that can suppress microbial virulence systems independent of any impact on growth are receiving increased attention. Quorum sensing (QS) is a cell-to-cell signalling communication system that controls the virulence behaviour of a broad spectrum of bacterial pathogens. QS systems have been proposed as an effective target, particularly as they control biofilm formation in pathogens, a key driver of antibiotic ineffectiveness. In this study, we identified coumarin, a natural plant phenolic compound, as a novel QS inhibitor, with potent anti-virulence activity in a broad spectrum of pathogens. Using a range of biosensor systems, coumarin was active against short, medium and long chain N-acyl-homoserine lactones, independent of any effect on growth. To determine if this suppression was linked to anti-virulence activity, key virulence systems were studied in the nosocomial pathogen Pseudomonas aeruginosa. Consistent with suppression of QS, coumarin inhibited biofilm, the production of phenazines and swarming motility in this organism potentially linked to reduced expression of the rhlI and pqsA quorum sensing genes. Furthermore, coumarin significantly inhibited biofilm formation and protease activity in other bacterial pathogens and inhibited bioluminescence in Aliivibrio fischeri. In light of these findings, coumarin would appear to have potential as a novel quorum sensing inhibitor with a broad spectrum of action.
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Affiliation(s)
- José A Gutiérrez-Barranquero
- BIOMERIT Research Centre, School of Microbiology, University College Cork, National University of Ireland, Cork, Ireland
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Ottaviano G, Staffieri C, Favaretto N, Fasanaro E, Abate D, de Filippis C, Staffieri A, Marioni G. Burkholderia cepacia complex isolation in non-polypoid chronic rhinosinusitis. Am J Otolaryngol 2014; 35:598-602. [PMID: 24976594 DOI: 10.1016/j.amjoto.2014.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 05/12/2014] [Indexed: 01/26/2023]
Abstract
PURPOSE Burkholderia cepacia complex (Bcc) infections of the head and neck have been infrequently reported in immunocompetent patients, while their association with cystic fibrosis is quite well known. One of the main problems associated with Bcc is their intrinsic resistance to most clinically-available antimicrobials. Bcc has already been isolated in sinonasal polyposis, while here we report for the first time on its isolation in patients with chronic rhinosinusitis (CRS) but no nasal polyposis. MATERIALS AND METHODS Thirty-four consecutive surgically-treated CRS patients without cystic fibrosis were recruited. RESULTS Bcc was isolated in 4 cases of CRS without polyposis, and in another case in sinonasal polyposis. All tested Bcc strains isolated in non-polypotic CRS were resistant to ciprofloxacin, amikacin, ertapenem, amoxicillin/clavulanate, cefotaxime, and gentamicin. CONCLUSIONS The novel finding of Bcc species in CRS without polyposis as well suggests that the mechanism by which these bacteria adhere to the epithelium of the upper respiratory tract may be important in the host's colonization.
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Ee R, Lim YL, Kin LX, Yin WF, Chan KG. Quorum sensing activity in Pandoraea pnomenusa RB38. SENSORS 2014; 14:10177-86. [PMID: 24919016 PMCID: PMC4118335 DOI: 10.3390/s140610177] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/25/2014] [Accepted: 05/28/2014] [Indexed: 11/16/2022]
Abstract
Strain RB38 was recovered from a former dumping area in Malaysia. MALDI-TOF mass spectrometry and genomic analysis identified strain RB-38 as Pandoraea pnomenusa. Various biosensors confirmed its quorum sensing properties. High resolution triple quadrupole liquid chromatography–mass spectrometry analysis was subsequently used to characterize the N-acyl homoserine lactone production profile of P. pnomenusa strain RB38, which validated that this isolate produced N-octanoyl homoserine lactone as a quorum sensing molecule. This is the first report of the production of N-octanoyl homoserine lactone by P. pnomenusa strain RB38.
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Affiliation(s)
- Robson Ee
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Yan-Lue Lim
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Lin-Xin Kin
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Wai-Fong Yin
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
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