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Cecropins as a marker of Spodoptera frugiperda immunosuppression during entomopathogenic bacterial challenge ArchiMer
Duvic, B.; Jouan, V.; Essa, N.; Girard, P-a; Pages, S.; Khattar, Z. Abi; Volkoff, N-a; Givaudan, A.; Destoumieux-garzon, Delphine; Escoubas, Jean-michel.
An antimicrobial peptide (AMP) of the cecropin family was isolated by HPLC from plasma of the insect pest, Spodoptera frugiperda. Its molecular mass is 3910.9 Da as determined by mass spectrometry. Thanks to the EST database Spodobase, we were able to describe 13 cDNAs encoding six different cecropins which belong to the sub-families CecA, CecB, CecC and CecD. The purified peptide identified as CecB1 was chemically synthesized (syCecB1). It was shown to be active against Gram-positive and Gram-negative bacteria as well as fungi. Two closely related entomopathogenic bacteria, Xenorhabdus nematophila F1 and Xenorhabdus mauleonii VC01(T) showed different susceptibility to syCecB1. Indeed, X. nematophila was sensitive to syCecB1 whereas X. mauleonii had a...
Tipo: Text Palavras-chave: Humoral immunity; Innate immunity; Immunosuppression; Lepidopteran; Invertebrate.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00086/19728/17485.pdf
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Cycle inhibiting factors (CIFs) are a growing family of functional cyclomodulins present in invertebrate and mammal bacterial pathogens Inra
Jubelin, G.; Chavez, C.V.; Taieb, F.; Banfield, M.J.; Samba-Louaka, A.; Nobe, R.; Nougayrede, J.P.; Zumbihl, R.; Givaudan, A.; Escoubas, J.M.; Oswald, E..
The cycle inhibiting factor (Cif) produced by enteropathogenic and enterohemorrhagic Escherichia coli was the first cyclomodulin to be identified that is injected into host cells via the type III secretion machinery. Cif provokes cytopathic effects characterized by G(1) and G(2) cell cycle arrests, accumulation of the cyclin-dependent kinase inhibitors (CKIs) p21(waf1/cip1) and p27(kip1) and formation of actin stress fibres. The X-ray crystal structure of Cif revealed it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases that share a conserved catalytic triad. Here we report the discovery and characterization of four Cif homologs encoded by different pathogenic or symbiotic bacteria isolated from...
Tipo: Journal Article Palavras-chave: ESCHERICHIA COLI; YERSINIA PSEUDOTUBERCULOSIS; BURKHOLDERIA PSEUDOMALLEI; CYCLOMODULIN.
Ano: 2009 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20102dd87998&uri=/notices/prodinra1/2010/10/
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FliZ, a flagellar regulator, is at the crossroads between motility, haemolysin expression and virulence in the insect pathogenic bacterium Xenorhabdus Inra
Lanois, A.; Jubelin, G.; Givaudan, A..
There is a complex interplay between the regulation of flagellar motility and the expression of virulence factors in many bacterial pathogens. We investigated the role of FliZ in the regulation of flagellar and virulence genes in Xenorhabdus nematophila, an insect pathogen. The fliZ gene is the second gene in the fliAZ operon in X. nematophila. In vivo transcription analysis revealed a positive feedback loop of fliAZ transcription in which FliZ activates flhDC, the master operon of flagellar regulon in X. nematophila, leading to an increased transcription of the FlhDC-dependent promoter of fliAZ. We also showed that fliAZ and flhDC mutants lacked motility, had no haemolysin or Tween lipase activity and displayed an attenuated virulence phenotype in...
Tipo: Journal Article Palavras-chave: FLAGELLE; XENORHABDUS NEMATOPHILA.
Ano: 2008 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008e24126f1&uri=/notices/prodinra1/2008/08/
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Heterologous expression of Bacillus thuringiensis vegetative insecticidal protein-encoding gene vip3LB in Photorhabdus temperata strain K122 and oral toxicity against the lepidoptera Ephestia kuehniella and Spodoptera littoralis Inra
Jamoussi, K.; Sellami, S.; Abdelkefi-Mesrati, L.; Givaudan, A.; Jaoua, S..
Photorhabdus temperata and Bacillus thuringiensis are entomopathogenic bacteria exhibiting toxicities against different insect larvae. Vegetative Insecticidal Protein Vip3LB is a Bacillus thuringiensis insecticidal protein secreted during the vegetative growth stage exhibiting lepidopteran specificity. In this study, we focused for the first time on the heterologous expression of vip3LB gene in Photorhabdus temperata strain K122. Firstly, Western blot analyses of whole cultures of recombinant Photorhabdus temperata showed that Vip3LB was produced and appeared lightly proteolysed. Cellular fractionation and proteinase K proteolysis showed that in vitro-cultured recombinant Photorhabdus temperata K122 accumulated Vip3LB in the cell and appeared not to...
Tipo: Journal Article Palavras-chave: BACILLUS THURINGIENSIS; INSECTICIDAL PROTEIN VIP3LB; HETEROLOGOUS EXPRESSION; PHOTORHABDUS TEMPERATA K122.
Ano: 2009 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD201079c1db68&uri=/notices/prodinra1/2010/10/
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Imd pathway isinvolvedintheinteractionof Drosophila melanogaster with the entomopathogenic bacteria, Xenorhabdus nematophila and Photorhabdus luminescens Inra
Aymeric, J.L.; Givaudan, A.; Duvic, B..
Xenorhabdus nematophila/Steinernema carpocapsae and Photorhabdus luminescens/Heterorhabditis bacteriophora are nemato-bacterial complexes highly pathogenic for insects. Using a syringe as artificial vector, we have analyzed the effects of the two bacteria, X. nematophila and P. luminescens on the genetic tool insect, Drosophila melanogaster. Both bacteria were found to kill adult flies in a dose dependent manner with X. nematophila being the fastest. On the other hand, when an injection of non-pathogenic bacteria, Escherichia coli, is performed 1 day before challenge with the entomopathogenic bacteria, then the survival of Drosophila flies was prolonged by at least 20 h. After injection of entomopathogenic bacteria, Drosophila mutant Dif1, affected on the...
Tipo: Journal Article Palavras-chave: MOUCHE DU VINAIGRE ENTOMOPATHOGENIC BACTERIA; PHOTORHABDUS LUMINESCENS; XENORHABDUS NEMATOPHILA; INSECT IMMUNITY; Imd PATHWAY; DROSOPHILA MELANOGASTER.
Ano: 2010 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2011686e4c1f&uri=/notices/prodinra1/2011/05/
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Plastic architecture of bacterial genome revealed by comparative genomics of Photorhabdus variants Inra
Gaudriault, S.; Pages, S.; Lanois, A.; Laroui, C.; Teyssier, C.; Jumas-Bilak, E.; Givaudan, A..
Background: The phenotypic consequences of large genomic architecture modifications within a clonal bacterial population are rarely evaluated because of the difficulties associated with using molecular approaches in a mixed population. Bacterial variants frequently arise among Photorhabdus luminescens, a nematode-symbiotic and insect-pathogenic bacterium. We therefore studied genome plasticity within Photorhabdus variants.Results: We used a combination of macrorestriction and DNA microarray experiments to perform a comparative genomic study of different P. luminescens TT01 variants. Prolonged culturing of TT01 strain and a genomic variant, collected from the laboratory-maintained symbiotic nematode, generated bacterial lineages composed of primary and...
Tipo: Journal Article Palavras-chave: PHOTORHABDUS; NEMATODE-SYMBIOTIC; INSECT-PATHOGENIC BACTERIUM; BACTERIAL GENOME ARCHITECTURE; PHENOTYPIC VARIANT.
Ano: 2008 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD201041309cda&uri=/notices/prodinra1/2010/10/
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Pleiotropic role of quorum-sensing autoinducer 2 in Photorhabdus luminescens Inra
Krin, E.; Chakroun, N.; Turlin, E.; Givaudan, A.; Gaboriau, F.; Bonne, I.; Rousselle, J.C.; Frangeul, L.; Lacroix, C.; Hullo, M.F.; Marisa, L.; Danchin, A.; Derzelle, S..
Bacterial virulence is an integrative process that may involve quorum sensing. In this work, we compared by global expression profiling the wild-type entomopathogenic Photorhabdus luminescens subsp. laumondii TT01 to a luxS-deficient mutant unable to synthesize the type 2 quorum-sensing inducer AI-2. AI-2 was shown to regulate more than 300 targets involved in most compartments and metabolic pathways of the cell. AI-2 is located high in the hierarchy, as it controls the expression of several transcriptional regulators. The regulatory effect of AI-2 appeared to be dose dependent. The luxS-deficient strain exhibited decreased biofilm formation and increased type IV/V pilus-dependent twitching motility. AI-2 activated its own synthesis and transport. It also...
Tipo: Journal Article Palavras-chave: BACTERIAL VIRULENCE; OXIDATIVE STRESS; PROTEOME ANALYSIS; OXIDATIVE STRESS.
Ano: 2006 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20085c5590af&uri=/notices/prodinra1/2009/03/
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Recent insight into the pathogenicity mechanisms of the emergent pathogen Photorhabdus asymbiotica Inra
Costa, S.C.P.; Chavez, C.V.; Jubelin, G.; Givaudan, A.; Escoubas, J.M.; Brehélin, M.; Zumbihl, R..
Photorhabdus asymbiotica is unique among the entomopathogenic bacteria of this genus in also being able to infect humans, leading to its isolation from some clinical samples. Recent comparative genomics data and the results of studies of interactions between bacteria and cells provide insight into the adaptation of this bacterium to its new niche, the human body
Tipo: Journal Article Palavras-chave: PHOTORABDUS ASYMBIOTICA; EMERGENT PATHOGEN; INSECT; MAN; COMPARATIVE GENOMICS; PHAGOCYTOSIS; APOPTOSIS; VIRULENCE FACTORS.
Ano: 2010 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2010764fee76&uri=/notices/prodinra1/2010/10/
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Site-specific antiphagocytic function of the Photorhabdus luminescens type III secretion system during insect colonization Inra
Brugirard-Ricaud, K.; Duchaud, E.; Givaudan, A.; Girard, P.A.; Kunst, F.; Boemare, N.; Brehélin, M.; Zumbihl, R..
Photorhabdus is an entomopathogenic bacterium belonging to the Enterobacteriaceae. The genome of the TT01 strain of Photorhabdus luminescens was recently sequenced and a large number of toxin-encoding genes were found. Genomic analysis predicted the presence on the chromosome of genes encoding a type three secretion system (TTSS), the main role of which is the delivery of effector proteins directly into eukaryotic host cells. We report here the functional characterization of the TTSS. The locus identified encodes the secretion/translocation apparatus, gene expression regulators and an effector protein - LopT - homologous to the Yersinia cysteine protease cytotoxin YopT. Heterologous expression in Yersinia demonstrated that LopT was translocated into mammal...
Tipo: Journal Article Palavras-chave: ENTOMOPATHOGENIC BACTERIUM; GENE EXPRESSION; ENTOMOPATHOGENIC NEMATODE; INSECT CELL MEMBRANE.
Ano: 2005 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008e8fb85eb&uri=/notices/prodinra1/2009/03/
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Stages of infection during the tripartite interaction between Xenorhabdus nematophila, its nematode vector, and insect hosts Inra
Sicard, M.; Brugirard-Ricaud, K.; Pages, S.; Lanois, A.; Boemare, N.; Brehélin, M.; Givaudan, A..
Bacteria of the genus Xenorhabdus are mutually associated with entomopathogenic nematodes of the genus Steinernema and are pathogenic to a broad spectrum of insects. The nematodes act as vectors, transmitting the bacteria to insect larvae, which die within a few days of infection. We characterized the early stages of bacterial infection in the insects by constructing a constitutive green fluorescent protein (GFP)-labeled Xenorhabdus nematophila strain. We injected the GFP-labeled bacteria into insects and monitored infection. We found that the bacteria had an extracellular life cycle in the hemolymph and rapidly colonized the anterior midgut region in Spodoptera littoralis larvae. Electron microscopy showed that the bacteria occupied the extracellular...
Tipo: Journal Article Palavras-chave: XENORHABDUS; ENTOMOPATHOGENIC NEMATODE; STEINERNEMA; GFP-LABELED; INTESTINAL VESICLE; SPODOPTERA.
Ano: 2004 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008345034c5&uri=/notices/prodinra1/2009/03/
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The cyclomodulin Cif of Photorhabdus luminescens inhibits insect cell proliferation and triggers host cell death by apoptosis Inra
Varela Chavez, C.; Jubelin, G.; Courties, G.; Gomard, A.; Ginibre, N.; Pages, S.; Taieb, F.; Girard, P.A.; Oswald, E.; Givaudan, A.; Zumbihl, R.; Escoubas, J.M..
Cycle inhibiting factors (Cif) constitute a broad family of cyclomodulins present in bacterial pathogens of invertebrates and mammals. Cif proteins are thought to be type III effectors capable of arresting the cell cycle at G2/M phase transition in human cell lines. We report here the first direct functional analysis of CifPl, from the entomopathogenic bacterium Photorhabdus luminescens, in its insect host. The cifPl gene was expressed in P. luminescens cultures in vitro. The resulting protein was released into the culture medium, unlike the well characterized type III effector LopT. During locust infection, cifPl was expressed in both the hemolymph and the hematopoietic organ, but was not essential for P. luminescens virulence. CifPl inhibited...
Tipo: Journal Article Palavras-chave: PHOTORHABDUS; APOPTOSIS; CYCLE INHIBITING FACTOR; CIF; TYPE III SECRETION SYSTEM.
Ano: 2010 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20119b3aacae&uri=/notices/prodinra1/2011/05/
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The dlt Operon of Bacillus cereus Is Required for Resistance to Cationic Antimicrobial Peptides and for Virulence in Insects Inra
Abi-Khattar, Z.; Rejasse, A.; Destoumieux-Garzón, D.; Escoubas, J.M.; Sanchis Borja, V.; Lereclus, D.; Givaudan, A.; Kallassy, M.; Nielsen-Leroux, C.; Gaudriault, S..
The dlt operon encodes proteins that alanylate teichoic acids, the major components of cell walls of gram-positive bacteria. This generates a net positive charge on bacterial cell walls, repulsing positively charged molecules and conferring resistance to animal and human cationic antimicrobial peptides (AMPs) in gram-positive pathogenic bacteria. AMPs damage the bacterial membrane and are the most effective components of the humoral immune response against bacteria. We investigated the role of the dlt operon in insect virulence by inactivating this operon in Bacillus cereus, which is both an opportunistic human pathogen and an insect pathogen. The {Delta}dltBc mutant displayed several morphological alterations but grew at a rate similar to that...
Tipo: Journal Article Palavras-chave: OPERON dlt.
Ano: 2009 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2011b0f035d5&uri=/notices/prodinra1/2011/05/
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The major outer membrane protein OmpU of Vibrio splendidus contributes to host antimicrobial peptide resistance and is required for virulence in the oyster Crassostrea gigas Inra
Duperthuy, M.; Binesse, J.; Le Roux, F.; Romestand, B.; Caro, A.; Got, P.; Givaudan, A.; Mazel, D.; Blachère, E.; Destoumieux-Garzón, D..
Vibrio splendidus, strain LGP32, is an oyster pathogen associated with the summer mortalities affecting the production of Crassostrea gigas oysters worldwide. Vibrio splendidus LGP32 was shown to resist to up to 10 µM Cg-Def defensin and Cg-BPI bactericidal permeability increasing protein, two antimicrobial peptides/proteins (AMPs) involved in C. gigas immunity. The resistance to both oyster Cg-Def and Cg-BPI and standard AMPs (polymyxin B, protegrin, human BPI) was dependent on the ompU gene. Indeed, upon ompU inactivation, minimal bactericidal concentrations decreased by up to fourfold. AMP resistance was restored upon ectopic expression of ompU. The susceptibility of bacterial membranes to AMP-induced damages was independent of the ompU-mediated AMP...
Tipo: Journal Article Palavras-chave: CRASSOSTREA GIGAS; VIBRIO SPLENDIDUS; OmpU OYSTER.
Ano: 2010 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20112f6d12&uri=/notices/prodinra1/2011/05/
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The PhoP-PhoQ two-component regulatory system of Photorhabdus luminescens is essential for virulence in insects Inra
Derzelle, S.; Turlin, E.; Duchaud, E.; Pages, S.; Kunst, F.; Givaudan, A.; Danchin, A..
Photorhabdus luminescens is a symbiont of entomopathogenic nematodes. Analysis of the genome sequence of this organism revealed a homologue of PhoP-PhoQ, a two-component system associated with virulence in intracellular bacterial pathogens. This organism was shown to respond to the availability of environmental magnesium. A mutant with a knockout mutation in the regulatory component of this system (phoP) had no obvious growth defect. It was, however, more motile and more sensitive to antimicrobial peptides than its wild-type parent. Remarkably, the mutation eliminated virulence in an insect model. No insect mortality was observed after injection of a large number of the phoP bacteria, while very small amounts of parental cells killed insect larvae in less...
Tipo: Journal Article Palavras-chave: ENTOMOPATHOGENIC NEMATODE; GENOME SEQUENCE; BACTERIAL PATHOGENE; VIRULENCE; INSECT MODEL; MAGNESIUM.
Ano: 2004 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008acbe701f&uri=/notices/prodinra1/2009/03/
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The xaxAB genes encoding a new apoptotic toxin from the insect pathogen Xenorhabdus nematophila are present in plant and human pathogens Inra
Vigneux, F.; Zumbihl, R.; Jubelin, G.; Ribeiro, C.; Poncet, J.; Baghdiguian, S.; Givaudan, A.; Brehélin, M..
Xenorhabdus nematophila, a member of the Enterobacteriaceae, kills many species of insects by strongly depressing the immune system and colonizing the entire body. A peptide cytotoxin has been purified from X. nematophila broth growth, and the cytolytic effect on insect immunocytes and hemolytic effect on mammalian red blood cells of this toxin have been described (Ribeiro, C., Vignes, M., and Brehelin, M. (2003) J. Mal. Chem. 278, 3030-3039). We show here that this toxin, Xenorhabdus alpha-xenorhabdolysin (Xax), triggers apoptosis in both insect and mammalian cells. We also report the cloning and sequencing of two genes, xaxAB, encoding this toxin in X. nematophila. The expression of both genes in recombinant Escherichia coli led to the production of...
Tipo: Journal Article Palavras-chave: IMMUNE SYSTEM; ENTOMOPATHOGENIC BACTERIA; CYTOTOXIN.
Ano: 2007 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008d7f6e01&uri=/notices/prodinra1/2010/11/
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Units of plasticity in bacterial genomes: new insight from the comparative genomics of two bacteria interacting with invertebrates, Photorhabdus and Xenorhabdus Inra
Ogier, J.C.; Calteau, A.; Forst, S.; Goodrich-Blair, H.; Roche, D.; Rouy, Z.; Suen, G.; Zumbihl, R.; Givaudan, A.; Tailliez, P.; Médigue, C.; Gaudriault, S..
BackgroundFlexible genomes facilitate bacterial evolution and are classically organized into polymorphic strain-specific segments called regions of genomic plasticity (RGPs). Using a new web tool, RGPFinder, we investigated plasticity units in bacterial genomes, by exhaustive description of the RGPs in two Photorhabdus and two Xenorhabdus strains, belonging to the Enterobacteriaceae and interacting with invertebrates (insects and nematodes).ResultsRGPs account for about 60% of the genome in each of the four genomes studied. We classified RGPs into genomic islands (GIs), prophages and two new classes of RGP without the features of classical mobile genetic elements (MGEs) but harboring genes encoding enzymes catalyzing DNA recombination (RGPmob), or with no...
Tipo: Journal Article Palavras-chave: PHOTORHABDUS; XENORHABDUS; RGPs; RGPFinder; PLASTICITE.
Ano: 2010 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2011781d9a80&uri=/notices/prodinra1/2011/05/
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Whole-genome comparison between Photorhabdus strains to identify genomic regions involved in the specificity of nematode interaction Inra
Gaudriault, S.; Duchaud, E.; Lanois, A.; Canoy, A.S.; Bourot, S.; DeRose, R.; Kunst, F.; Boemare, N.; Givaudan, A..
The bacterium Photorhabdus establishes a highly specific association with Heterorhabditis, its nematode host. Photorhabdus strains associated with Heterorhabditis bacteriophora or Heterorhabditis megidis were compared using a Photorhabdus DNA microarray. We describe 31 regions belonging to the Photorhabdus flexible gene pool. Distribution analysis of regions among the Photorhabdus genus identified loci possibly involved in nematode specificity
Tipo: Journal Article Palavras-chave: PHOTORHABDUS; HETERORHABDITIS; GENE POOL; GENOME SEQUENCE; HYBRIDIZATION; CHROMOSOMAL SEQUENCE.
Ano: 2006 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD200879731a17&uri=/notices/prodinra1/2009/01/
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