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Talà A, Delle Side D, Buccolieri G, Tredici SM, Velardi L, Paladini F, De Stefano M, Nassisi V, Alifano P. Exposure to static magnetic field stimulates quorum sensing circuit in luminescent Vibrio strains of the Harveyi clade. PLoS One 2014; 9:e100825. [PMID: 24960170 PMCID: PMC4069165 DOI: 10.1371/journal.pone.0100825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 05/29/2014] [Indexed: 11/18/2022] Open
Abstract
In this study, the evidence of electron-dense magnetic inclusions with polyhedral shape in the cytoplasm of Harveyi clade Vibrio strain PS1, a bioluminescent bacterium living in symbiosis with marine organisms, led us to investigate the behavior of this bacterium under exposure to static magnetic fields ranging between 20 and 2000 Gauss. When compared to sham-exposed, the light emission of magnetic field-exposed bacteria growing on solid medium at 18°C ±0.1°C was increased up to two-fold as a function of dose and growth phase. Stimulation of bioluminescence by magnetic field was more pronounced during the post-exponential growth and stationary phase, and was lost when bacteria were grown in the presence of the iron chelator deferoxamine, which caused disassembly of the magnetic inclusions suggesting their involvement in magnetic response. As in luminescent Vibrio spp. bioluminescence is regulated by quorum sensing, possible effects of magnetic field exposure on quorum sensing were investigated. Measurement of mRNA levels by reverse transcriptase real time-PCR demonstrated that luxR regulatory gene and luxCDABE operon coding for luciferase and fatty acid reductase complex were significantly up-regulated in magnetic field-exposed bacteria. In contrast, genes coding for a type III secretion system, whose expression was negatively affected by LuxR, were down-regulated. Up-regulation of luxR paralleled with down-regulation of small RNAs that mediate destabilization of luxR mRNA in quorum sensing signaling pathways. The results of experiments with the well-studied Vibrio campbellii strain BB120 (originally classified as Vibrio harveyi) and derivative mutants unable to synthesize autoinducers suggest that the effects of magnetic fields on quorum sensing may be mediated by AI-2, the interspecies quorum sensing signal molecule.
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Affiliation(s)
- Adelfia Talà
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce, Italy
| | - Domenico Delle Side
- Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento INFN – Lecce, Lecce, Italy
| | - Giovanni Buccolieri
- Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento INFN – Lecce, Lecce, Italy
| | | | - Luciano Velardi
- Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento INFN – Lecce, Lecce, Italy
| | - Fabio Paladini
- Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento INFN – Lecce, Lecce, Italy
| | - Mario De Stefano
- Dipartimento di Scienze Ambientali, Seconda Università di Napoli, Caserta, Italy
| | - Vincenzo Nassisi
- Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento INFN – Lecce, Lecce, Italy
| | - Pietro Alifano
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce, Italy
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Lowery CA, Salzameda NT, Sawada D, Kaufmann GF, Janda KD. Medicinal chemistry as a conduit for the modulation of quorum sensing. J Med Chem 2010; 53:7467-89. [PMID: 20669927 DOI: 10.1021/jm901742e] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Colin A Lowery
- Department of Chemistry and Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, California 92037, USA
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Galloway WRJD, Hodgkinson JT, Bowden SD, Welch M, Spring DR. Quorum Sensing in Gram-Negative Bacteria: Small-Molecule Modulation of AHL and AI-2 Quorum Sensing Pathways. Chem Rev 2010; 111:28-67. [DOI: 10.1021/cr100109t] [Citation(s) in RCA: 454] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Warren R. J. D. Galloway
- Department of Chemistry and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1EW U.K
| | - James T. Hodgkinson
- Department of Chemistry and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1EW U.K
| | - Steven D. Bowden
- Department of Chemistry and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1EW U.K
| | - Martin Welch
- Department of Chemistry and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1EW U.K
| | - David R. Spring
- Department of Chemistry and Department of Biochemistry, University of Cambridge, Cambridge, CB2 1EW U.K
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Holmes K, Tavender TJ, Winzer K, Wells JM, Hardie KR. AI-2 does not function as a quorum sensing molecule in Campylobacter jejuni during exponential growth in vitro. BMC Microbiol 2009; 9:214. [PMID: 19814796 PMCID: PMC2772989 DOI: 10.1186/1471-2180-9-214] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 10/08/2009] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Campylobacter jejuni contains a homologue of the luxS gene shown to be responsible for the production of the signalling molecule autoinducer-2 (AI-2) in Vibrio harveyi and Vibrio cholerae. The aim of this study was to determine whether AI-2 acted as a diffusible quorum sensing signal controlling C. jejuni gene expression when it is produced at high levels during mid exponential growth phase. RESULTS AI-2 activity was produced by the parental strain NCTC 11168 when grown in rich Mueller-Hinton broth (MHB) as expected, but interestingly was not present in defined Modified Eagles Medium (MEM-alpha). Consistent with previous studies, the luxS mutant showed comparable growth rates to the parental strain and exhibited decreased motility halos in both MEM-alpha and MHB. Microarray analysis of genes differentially expressed in wild type and luxS mutant strains showed that many effects on mRNA transcript abundance were dependent on the growth medium and linked to metabolic functions including methionine metabolism. Addition of exogenously produced AI-2 to the wild type and the luxS mutant, growing exponentially in either MHB or MEM-alpha did not induce any transcriptional changes as analysed by microarray. CONCLUSION Taken together these results led us to conclude that there is no evidence for the role of AI-2 in cell-to-cell communication in C. jejuni strain NCTC 11168 under the growth conditions used, and that the effects of the luxS mutation on the transcriptome are related to the consequential loss of function in the activated methyl cycle.
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Affiliation(s)
- Kathryn Holmes
- Pathogens: Molecular Microbiology, BBSRC Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK
- Department of Clinical Medicine, Trinity College, Adelaide and Meath Hospital, Dublin 24, Ireland
| | - Tim J Tavender
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Clifton Boulevard, University Park, Nottingham NG7 2RD, UK
- Michael Smith Building, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Klaus Winzer
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Clifton Boulevard, University Park, Nottingham NG7 2RD, UK
| | - Jerry M Wells
- Pathogens: Molecular Microbiology, BBSRC Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK
- Host-Microbe Interactomics, Animal Sciences Department, University of Wageningen, The Netherlands
| | - Kim R Hardie
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Clifton Boulevard, University Park, Nottingham NG7 2RD, UK
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Ni N, Choudhary G, Li M, Wang B. A new phenothiazine structural scaffold as inhibitors of bacterial quorum sensing in Vibrio harveyi. Biochem Biophys Res Commun 2009; 382:153-6. [DOI: 10.1016/j.bbrc.2009.02.157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 02/26/2009] [Indexed: 02/03/2023]
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Ni N, Li M, Wang J, Wang B. Inhibitors and antagonists of bacterial quorum sensing. Med Res Rev 2009; 29:65-124. [DOI: 10.1002/med.20145] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Li M, Ni N, Chou HT, Lu CD, Tai PC, Wang B. Structure-based discovery and experimental verification of novel AI-2 quorum sensing inhibitors against Vibrio harveyi. ChemMedChem 2008; 3:1242-9. [PMID: 18537200 DOI: 10.1002/cmdc.200800076] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Quorum sensing has been implicated in the control of pathologically relevant bacterial behavior such as secretion of virulence factors, biofilm formation, sporulation, and swarming motility. The AI-2 quorum sensing pathway is found in both gram-positive and gram-negative bacteria. Therefore, antagonizing AI-2 quorum sensing is a possible approach to modifying bacterial behaviour. However, efforts in developing inhibitors of AI-2-mediated quorum sensing are especially lacking. High-throughput virtual screening using the V. harveyi LuxP crystal structure identified two compounds that were found to antagonize AI-2-mediated quorum sensing in V. harveyi without cytotoxicity. The sulfone functionality of these inhibitors was identified as critical to their ability to mimic the natural ligand in their interactions with Arg 215 and Arg 310 of the active site.
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Affiliation(s)
- Minyong Li
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30302-4098, USA
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Girennavar B, Cepeda ML, Soni KA, Vikram A, Jesudhasan P, Jayaprakasha G, Pillai SD, Patil BS. Grapefruit juice and its furocoumarins inhibits autoinducer signaling and biofilm formation in bacteria. Int J Food Microbiol 2008; 125:204-8. [DOI: 10.1016/j.ijfoodmicro.2008.03.028] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 02/16/2008] [Accepted: 03/24/2008] [Indexed: 10/22/2022]
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Abstract
Using UV, CD, and NMR, we demonstrate that the important bacterial signaling molecule involved in biofilm formation, cyclic diguanosine monophosphate (c-di-GMP), exists as a mixture of five different but related structures in an equilibrium that is sensitive both to its concentration and to the metal present. At the lower concentrations used for UV and CD work (0.05-0.5 mM), Li(+), Na(+), Cs(+), and Mg(2+) favor a bimolecular self-intercalated structure, while K(+), Rb(+), and NH(4)(+) favor formation of one or more guanine quartet complexes as well. At the higher NMR concentrations ( approximately 30 mM), the bimolecular structures associate and rearrange to a mixture of all-syn and all-anti tetramolecular and octamolecular quartet complexes. With K(+) the octamolecular complexes predominate, while with Li(+) the tetramolecular and octamolecular quartet complexes are present in approximately equal amounts, along with the bimolecular structure. We also find that both guanine amino groups in c-di-GMP are essential for formation of the quartets, because substitution of inosine for one guanosine allows formation of only the bimolecular structure. Further, two molecules of c-di-GMP tethered together are constrained in such a way that limits their ability to form these quartet complexes. The polymorphism we describe may provide different options for this signaling molecule when performing its functions in a bacterial cell, with K(+) and its own local concentration controlling the equilibrium.
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Affiliation(s)
- Zhaoying Zhang
- Department of Chemistry and Chemical Biology, 610 Taylor Road, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854
| | - Seho Kim
- Department of Chemistry and Chemical Biology, 610 Taylor Road, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854
| | - Barbara L. Gaffney
- Department of Chemistry and Chemical Biology, 610 Taylor Road, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854
| | - Roger A. Jones
- Department of Chemistry and Chemical Biology, 610 Taylor Road, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854
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