Consulta: creatorFacets:"Mazel, Didier"
Registros recuperados: 9
Data/hora: 09/06/2024 13:49:53

A single regulatory gene is sufficient to alter Vibrio aestuarianus pathogenicity in oysters
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Goudenege, David; Travers, Marie-agnes; Lemire, Astrid; Petton, Bruno; Haffner, Philippe; Labreuche, Yannick; Tourbiez, Delphine; Mangenot, Sophie; Calteau, Alexandra; Mazel, Didier; Nicolas, Jean-louis; Jacq, Annick; Le Roux, Frederique.
Oyster diseases caused by pathogenic vibrios pose a major challenge to the sustainability of oyster farming. In France since 2012 a disease affecting specifically adult oysters has been associated with the presence of Vibrio aestuarianus. Here, by combining genome comparison, phylogenetic analyses and high throughput infections of strains isolated before or during the recent outbreaks, we show that virulent strains cluster into two V. aestuarianus lineages independently of the sampling dates. The bacterial lethal dose was not different between strains isolated before or after 2012. Hence the emergence of a new highly virulent clonal strain is unlikely. Each lineage comprises nearly identical strains, the majority of them being virulent, suggesting that...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00226/33685/32530.pdf

The emergence of Vibrio pathogens in Europe: ecology, evolution, and pathogenesis (Paris, 11-12th March 2015)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Roux, Frederique; Wegner, K. Mathias; Baker-austin, Craig; Vezzulli, Luigi; Osorio, Carlos R.; Amaro, Carmen; Ritchie, Jennifer M.; Defoirdt, Tom; Destoumieux-garzon, Delphine; Blokesch, Melanie; Mazel, Didier; Jacq, Annick; Cava, Felipe; Gram, Lone; Wendling, Carolin C.; Strauch, Eckhard; Kirschner, Alexander; Huehn, Stephan.
Global change has caused a worldwide increase in reports of Vibrio-associated diseases with ecosystem-wide impacts on humans and marine animals. In Europe, higher prevalence of human infections followed regional climatic trends with outbreaks occurring during episodes of unusually warm weather. Similar patterns were also observed in Vibrio-associated diseases affecting marine organisms such as fish, bivalves and corals. Basic knowledge is still lacking on the ecology and evolutionary biology of these bacteria as well as on their virulence mechanisms. Current limitations in experimental systems to study infection and the lack of diagnostic tools still prevent a better understanding of Vibrio emergence. A major challenge is to foster cooperation between...
Tipo: Text
Palavras-chave: Global warming; Human health; Aquaculture; Interactions; Animal model; Bacterial disease; Genome plasticity; European network.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00278/38952/37494.pdf

Comparative genomics of pathogenic lineages of Vibrio nigripulchritudo identifies virulence-associated traits
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Goudenege, David; Labreuche, Yannick; Krin, Evelyne; Ansquer, Dominique; Mangenot, Sophie; Calteau, Alexandra; Medigue, Claudine; Mazel, Didier; Polz, Martin F.; Le Roux, Frederique.
Vibrio nigripulchritudo is an emerging pathogen of farmed shrimp in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have suggested that pathogenicity is linked to particular lineages. Here, we performed high-throughput sequencing-based comparative genome analysis of 16 V. nigripulchritudo strains to explore the genomic diversity and evolutionary history of pathogen-containing lineages and to identify pathogen-specific genetic elements. Our phylogenetic analysis revealed three pathogen-containing V. nigripulchritudo clades, including two clades previously identified from New Caledonia and one novel clade comprising putatively...
Tipo: Text
Palavras-chave: Horizontal gene transfer; Nigritoxin; Phylogeny; Shrimp; Virulence; Vibrio.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00160/27117/28369.pdf

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
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Duperthuy, Marylise; Binesse, Johan; Le Roux, Frederique; Romestand, Bernard; Caro, Audrey; Got, Patrice; Givaudan, Alain; Mazel, Didier; Bachere, Evelyne; Destoumieux Garzon, Delphine.
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 mu M 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: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11421/8044.pdf

Construction of a Vibrio splendidus Vsm metalloprotease mutant using a novel counter-selectable suicide vector
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Leroux, Frederique; Binesse, Johan; Saulnier, Denis; Mazel, Didier.
splendidus is a dominant culturable Vibrio in seawater, but strains related to this group are also associated with mortalities in a variety of marine animals. The determinants encoding the pathogenic properties of these strains are still poorly known, however, the recent sequencing of the genome of V. splendidus LGP32, an oyster pathogen, offers the opportunity to decipher the basis of the virulence properties by the disruption of candidate genes. We have developed a novel suicide vector based on the pir-dependant R6K replicative origin, which can be transferred by RP4 based conjugation to, potentially, any Vibrio strain, and which also carries the plasmid F toxin ccdB gene under the control of the PBAD promoter. We demonstrate that this genetic system...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3292.pdf

Identification of a plasmid associated with virulence in Vibrio nigripulchritudo, a pathogen of the shrimp Litopenaeus stylirostris
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Reynaud, Yann; Saulnier, Denis; Mazel, Didier; Goarant, Cyrille; Le Roux, Frédérique.
Tipo: Text
Palavras-chave: Pathogenic vibrios; Pathology; Litopeneaus stylirostris; Vibrio nigripulchritudo.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3432.pdf

Vibrio aestuarianus zinc metalloprotease causes lethality in the Pacific oyster Crassostrea gigas and impairs the host cellular immune defenses
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Labreuche, Yannick; Le Roux, Frederique; Henry, Joel; Zatylny, Celine; Huvet, Arnaud; Lambert, Christophe; Soudant, Philippe; Mazel, Didier; Nicolas, Jean-louis.
Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemical and genetic approaches were developed. ECP protease activity and lethality were shown to be significantly reduced following incubation with metal chelators, suggesting the involvement of a zinc metalloprotease. An open reading frame of 1836 bp encoding a 611-aa metalloprotease (designated yam) was identified. The deduced protein sequence showed high homology to other Vibrio metalloproteases reported to be involved in pathogenicity. To further confirm the role of this enzyme in ECP...
Tipo: Text
Palavras-chave: Vibrio aestuarianus; Metalloprotease; Crassostrea gigas; Oyster; Hemocytes; Extracellular products.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00015/12649/9588.pdf

Genome sequence of Vibrio splendidus: an abundant planctonic marine species with a large genotypic diversity
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Roux, Frederique; Zouine, Mohamed; Chakroun, Nesrine; Binesse, Johan; Saulnier, Denis; Bouchier, Christiane; Zidane, Nora; Ma, Laurence; Rusniok, Christophe; Lajus, Aurelie; Buchrieser, Carmen; Medigue, Claudine; Polz, Martin F.; Mazel, Didier.
P&gt;Vibrio splendidus is a dominant Vibrio species in seawater presenting a remarkable genetic diversity; several strains have been linked to invertebrate's mortality. We report the complete genome sequence of V. splendidus LGP32, an oyster pathogen, and its comparison with partial genome sequences from related strains. As is typical for the genus, V. splendidus LGP32 contains two chromosomes (3.29 and 1.67 Mb) and most essential cellular processes are encoded by chromosome 1. Comparison with two other V. splendidus partial genome sequences (strains 12B01 and Med222) confirms the previously suggested high genotypic diversity within this species and led to the identification of numerous strain-specific regions that could frequently not be assigned to a...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6632.pdf

Virulence of an emerging pathogenic lineage of Vibrio nigripulchritudo is dependent on two plasmids
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Roux, Frederique; Labreuche, Yannick; Davis, Brigid M.; Iqbal, Naeem; Mangenot, Sophie; Goarant, Cyrille; Mazel, Didier; Waldor, Matthew K.
Vibrioses are the predominant bacterial infections in marine shrimp farms. Vibrio nigripulchritudo is an emerging pathogen of the cultured shrimp Litopenaeus stylirostris in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have revealed that recent pathogenic V. nigripulchritudo isolates from New Caledonia all cluster into a monophyletic clade and contain a small plasmid, pB1067. Here, we report that a large plasmid, pA1066 (247 kb), can also serve as a marker for virulent V. nigripulchritudo, and that an ancestral version of this plasmid was likely acquired prior to other virulence-linked markers. Additionally, we demonstrate that...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14196/11469.pdf