|
|
|
| Registros recuperados: 17 | |
|
|
| 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 |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
| |
|
|
| 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/ |
| |
|
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
|
|
| 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/ |
| |
| Registros recuperados: 17 | |
|
|
|
