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| Registros recuperados: 36 | |
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| Lemire, Astrid; Goudenege, David; Versigny, Tiphaine; Petton, Bruno; Calteau, Alexandra; Labreuche, Yannick; Le Roux, Frederique. |
| Disease in oysters has been steadily rising over the past decade, threatening the long-term survival of commercial and natural stocks. Our understanding and management of such diseases are of critical importance as aquaculture is an important aspect of dealing with the approaching worldwide food shortage. Although some bacteria of the Vibrio genus isolated from diseased oysters have been demonstrated to be pathogenic by experimental infection, direct causality has not been established. Little is known about the dynamics of how the bacterial population hosted by oysters changes during disease progression. Combining experimental ecology, a high-throughput infection assay and genome sequencing, we show that the onset of disease in oysters is associated with... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00244/35565/34107.pdf |
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| Nguyen, An Ngoc; Disconzi, Elena; Charriere, Guillaume; Destoumieux-garzon, Delphine; Bouloc, Philippe; Le Roux, Frederique; Jacq, Annick. |
| CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarSNarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi, respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus Glade, was found to have four copies of csrB, named csrB1-4, compared to two to three copies in other Vibrio species. Here, we show that the extra csrB4 copy results from a csrB3 gene duplication, a characteristic of the Splendidus Glade. Interestingly, csrB genes are regulated in different... |
| Tipo: Text |
Palavras-chave: Bacterial gene regulation; Bacterial sRNAs; Transcriptomics; Vibrio pathogenic to oysters; Host-pathogen interactions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00476/58785/61319.pdf |
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| Renault, Tristan; Le Roux, Frederique; Berthe, Franck; Arzul, Isabelle; Miossec, Laurence; Robert, Maeva; Chollet, Bruno. |
| Nous disposons aujourd'hui d'o utils diagnostiques sensibles et spécifiques (PCR, HIS ... ) et d'un protocole de transmission de l' infection qui permettent d'assurer un suivi des productions larvaires en écloserie de bivalves pour les espèces considérées comme sensibles aux infections à herpèsvirus, mais également pour de nouvelles espèces. En effet, des mortalités massives (100 %) ont été rapportées dans une écloserie de coquille St-Jacques en Bretagne et ont pu être associées à la détection de OsHV -1. Les résultats obtenus concernant cette espèce, Pecten maximus, complètent et reflètent l'ensemble des travaux réalisés. |
| Tipo: Text |
Palavras-chave: Pathologie; Epidémiologie; Virus; Herpès virus; Bivalves; Crassostrea gigas; Ruditapes philippinarum; Pecten maximus. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00043/15472/12851.pdf |
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| Le Roux, Frederique; Wegner, K. Mathias; Polz, Martin F.. |
| Disease dynamics in the wild are influenced by a number of ecological and evolutionary factors not addressed by traditional laboratory-based characterization of pathogens. Here we propose the oyster, Crassostrea gigas, as a model for studying the interaction of the environment, bacterial pathogens, and the host in disease dynamics. We show that an important first step is to ask whether the functional unit of pathogenesis is a bacterial clone, a population, or a consortium in order to assess triggers of disease outbreaks and devise appropriate monitoring tools. Moreover, the development of specific-pathogen-free (SPF) oysters has enabled assessment of the infection process under natural conditions. Finally, recent results show the importance of microbial... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00323/43466/46569.pdf |
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| Bruto, Maxime; James, Adele; Petton, Bruno; Labreuche, Yannick; Chenivesse, Sabine; Alunno-bruscia, Marianne; Polz, Martin F.; Le Roux, Frederique. |
| Vibrios are frequently associated with oyster mortality; however whether they are the primary causative agent or secondary opportunistic colonizers is not well understood. Here we combine analysis of natural infection dynamics, population genomics and molecular genetics to ask (i) to what extent oysters are passively colonized by Vibrio population present in the surrounding water, (ii) how populations turn over during pathogenicity events and (iii) what genetic factors are responsible for pathogenicity. We identified several populations of Vibrio preferentially associated with oyster tissues. Among these, Vibrio crassostreae is particularly abundant in diseased animals while nearly absent in the surrounding water, and its pathogenicity is correlated with... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00360/47137/49044.pdf |
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| Foulon, Valentin; Le Roux, Frederique; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe; Paul-pont, Ika. |
| Microplastics collected at sea harbour a high diversity of microorganisms including some Vibrio genus members, raising questions about the role of microplastics as a novel ecological niche for potentially pathogenic microorganisms. In the present study we investigated the adhesion dynamics of Vibrio crassostreae on polystyrene microparticles (micro-PS) using electronic and fluorescence microscopy techniques. Micro-PS were incubated with bacteria in different media (Zobell culture medium and artificial seawater) with or without natural marine aggregates. The highest percentage of colonised particles (38-100%) was observed in Zobell culture medium, which may be related to nutrient availability for production of pili and exopolysaccharide adhesion structures.... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00351/46210/45908.pdf |
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| Labreuche, Yannick; Pallandre, Laurane; Ansquer, Dominique; Herlin, Jose; Wapotro, Billy; Le Roux, Frederique. |
| Two recurring syndromes threaten the viability of the shrimp industry in New Caledonia, which represents the second largest export business. The "Syndrome 93" is a cold season disease due to Vibrio penaeicida affecting all shrimp farms, while the "Summer Syndrome" is a geographically restricted vibriosis caused by a virulent lineage of Vibrio nigripulchritudo. Microbiological procedures for diagnosis of these diseases are time-consuming and do not have the ability to discriminate the range of virulence potentials of V. nigripulchritudo. In this study, we developed a multiplex PCR method to simultaneously detect these two bacterial species and allow for pathotype discrimination. The detection limits of this assay, that includes an internal amplification... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00063/17398/15169.pdf |
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| 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>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 |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6632.pdf |
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| De Lorgeril, Julien; Lucasson, Aude; Petton, Bruno; Toulza, Eve; Montagnani, Caroline; Clerissi, Camille; Vidal-dupiol, Jeremie; Chaparro, Cristian; Galinier, Richard; Escoubas, Jean Michel; Haffner, Philippe; Degremont, Lionel; Charriere, Guillaume; Lafont, Maxime; Delort, Abigail; Vergnes, Agnes; Chiarello, Marlene; Faury, Nicole; Rubio, Tristan; Leroy, Marc; Perignon, Adeline; Regler, Denis; Morga, Benjamin; Alunno-bruscia, Marianne; Boudry, Pierre; Le Roux, Frederique; Destoumieux-garzon, Delphine; Gueguen, Yannick; Mitta, Guillaume. |
| Infectious diseases are mostly explored using reductionist approaches despite repeated evidence showing them to be strongly in fluenced by numerous interacting host and environmental factors. Many diseases with a complex aetiology therefore remain misunderstood. By developing a holistic approach to tackle the complexity of interactions, we decipher the complex intra-host interactions underlying Pacific oyster mortality syndrome affecting juveniles of Crassostrea gigas, the main oyster species exploited worldwide. Using experimental infections reproducing the natural route of infection and combining thorough molecular analyses of oyster families with contrasted susceptibilities, we demonstrate that the disease is caused by multiple infection with an initial... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57234/59228.pdf |
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| Wegner, K. Mathias; Piel, Damien; Bruto, Maxime; John, Uwe; Mao, Zhijuan; Alunno-bruscia, Marianne; Petton, Bruno; Le Roux, Frederique. |
| Bacteria of the Vibrio genus are the most predominant infectious agents threatening marine wildlife and aquaculture. Due to the large genetic diversity of these pathogens, the molecular determinants of Vibrio virulence are only poorly understood. Furthermore, studies tend to ignore co-evolutionary interactions between different host populations and their locally encountered Vibrio communities. Here, we explore the molecular targets of such co-evolutionary interactions by analyzing the genomes of nine Vibrio strains from the Splendidus-clade showing opposite virulence patterns towards two populations of Pacific oysters introduced into European Wadden Sea. By contrasting Vibrio phylogeny to their host specific virulence patterns, we could identify two core... |
| Tipo: Text |
Palavras-chave: Virulence; Host-pathogen interaction; Local adaptation; Biological invasion; Emerging disease; Wadden Sea. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62409/66669.pdf |
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| 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 |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14196/11469.pdf |
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| Rubio, Tristan; Oyanedel, Daniel; Labreuche, Yannick; Toulza, Eve; Luo, Xing; Bruto, Maxime; Chaparro, Cristian; Torres, Marta; De Lorgeril, Julien; Haffner, Philippe; Vidal-dupiol, Jeremie; Lagorce, Arnaud; Petton, Bruno; Mitta, Guillaume; Jacq, Annick; Le Roux, Frederique; Charriere, Guillaume; Destoumieux-garzon, Delphine. |
| Vibrio species cause infectious diseases in humans and animals, but they can also live as commensals within their host tissues. How Vibrio subverts the host defenses to mount a successful infection remains poorly understood, and this knowledge is critical for predicting and managing disease. Here, we have investigated the cellular and molecular mechanisms underpinning infection and colonization of 2 virulent Vibrio species in an ecologically relevant host model, oyster, to study interactions with marine Vibrio species. All Vibrio strains were recognized by the immune system, but only nonvirulent strains were controlled. We showed that virulent strains were cytotoxic to hemocytes, oyster immune cells. By analyzing host and bacterial transcriptional... |
| Tipo: Text |
Palavras-chave: T6SS; Toxin; Dual RNA-seq; Cytolysis; Pathogenesis. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00507/61837/65900.pdf |
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| Le Roux, Frederique; Goubet, A; Thompson, F; Faury, Nicole; Gay, Melanie; Swings, J; Saulnier, Denis. |
| Polyphasic analysis of four new Vibrio isolates originating from the haemolymph of diseased cultured oysters is described. The new isolates were closely related to Vibrio splendidus, having 98 % 16S rRNA gene sequence similarity. Phylogenetic analysis based on DNA gyrase subunit B (gyrB), RNA polymerase Quo factor (rpoD), replication origin-binding protein (rctB) and transmembrane regulatory protein (toxR) genes, fluorescent amplified fragment length polymorphism and DNA-DNA hybridization experiments clearly showed that the new isolates form a tight genomic group that is different from the currently known Vibrio species. It is proposed that these new isolates should be accommodated in a novel species, Vibrio gigantis sp. nov. Phenotypic features that... |
| Tipo: Text |
Palavras-chave: Vibrio gigantis; Haemoplymph; Disease; Crassostrea gigas; Oyster culture. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-792.pdf |
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| Thebault, Anne; Martin, Anne-genevieve; Le Coguic, Yvette; Hirata, Toshio; Tige, Gilbert; Pichot, Yves; Grizel, Henri; Berthe, Franck; Cochennec, Nathalie; Renault, Tristan; Le Roux, Frederique. |
| Le réseau REPAMO (Réseau de Pathologie des Mollusques) est un réseau de santé animale, qui s'occupe des coquillages marins du littoral français métropolitain. Les mollusques marins des côtes françaises représentent une ressource par la pêche, mais sont surtout une part importante de l'aquaculture. Les pertes liées aux maladies dans ce domaine d'activité sont aujourd'hui considérées comme l'un des principaux facteurs limitants de son développement au niveau mondial. Deux exemples récents suffisent à illustrer ce danger pour l'ostréiculture française : • La culture de l''huître plate Ostrea edulis, déjà atteinte par un parasite, Marteilia refringens, est passée en quelques années de 20 000 tonnes à 1800 tonnes, suite à une épizootie. En effet à la fin des... |
| Tipo: Text |
Palavras-chave: Réseau surveillance; Pathologie; Mollusques bivalves; Mortalité. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00098/20903/18522.pdf |
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| Oyanedel, Daniel; Labreuche, Yannick; Bruto, Maxime; Amraoui, Hajar; Robino, Etienne; Haffner, Philippe; Rubio, Tristan; Charrière, Guillaume; Le Roux, Frederique; Destoumieux-garzón, Delphine. |
| A major debate in evolutionary biology is whether virulence is maintained as an adaptive trait and/or evolves to non‐virulence. In the environment, virulence traits of non‐obligatory parasites are subjected to diverse selective pressures and trade‐offs. Here we focus on a population of Vibrio splendidus that displays moderate virulence for oysters. A MARTX (Multifunctional‐autoprocessing repeats‐in‐toxin) and a type‐six secretion system (T6SS) were found to be necessary for virulence toward oysters, while a region (wbe) involved in O‐antigen synthesis is necessary for resistance to predation against amoebae. Gene inactivation within the wbe region had major consequences on the O‐antigen structure, conferring lower immunogenicity, competitive advantage and... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00619/73070/72194.pdf |
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| 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 |
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| Piel, Damien; Bruto, Maxime; James, Adele; Labreuche, Yannick; Lambert, Christophe; Janicot, Adrian; Chenivesse, Sabine; Petton, Bruno; Wegner, K. Mathias; Stoudmann, Candice; Blokesch, Melanie; Le Roux, Frederique. |
| Pacific oyster mortality syndrome affects juveniles of Crassostrea gigas oysters and threatens the sustainability of commercial and natural stocks of this species. Vibrio crassostreae has been repeatedly isolated from diseased animals and the majority of the strains have been demonstrated to be virulent for oysters. In this study we showed that oyster farms exhibited a high prevalence of a virulence plasmid carried by V. crassostreae while oysters, at an adult stage, were reservoirs of this virulent population. The pathogenicity of V. crassostreae depends on a novel transcriptional regulator, which activates the bidirectional promoter of a Type 6 Secretion System (T6SS) genes cluster. Both the T6SS and a second chromosomal virulence factor, r5.7, are... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00510/62129/66343.pdf |
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| Beliaeff, Benoit; Chim, Liet; Della Patrona, Luc; Goyard, Emmanuel; Herlin, Jose; Labreuche, Yannick; Walling, Emilie; Ansquer, Dominique; Brun, Pierre; Castex, Mathieu; Coatanea, Denis; Courties, Claude; De Lorgeril, Julien; Dufour, Robert; Frappier, Julie; Goarant, Cyrille; Huber, Matthias; Lemaire, Pierrette; Lemonnier, Hugues; Loubersac, Lionel; Le Roux, Frederique; Lucas, Ronan; Patrois, Jacques; Peignon, Jean-marie; Pham, Dominique; Ramage, Yannick; Soulard, Benoit; Vic, Marlene; Vourey, Elodie; Wabete, Nelly. |
| New Caledonian shrimp farming feasibility studies started in the mid-seventies. Today ca. 2000 tons of Litopenaeus stylirostris, introduced in 1978, are semi-intensively produced each year. Since fifteen years, production has been impacted by two seasonal vibriosis, the “Summer” syndrome caused by Vibrio nigripulchritudo in relation to pond bottom and water column quality, and the “Winter Syndrome” caused by Vibrio penaeicida in relation to drastic temperature drops . With the ambition of elucidating processes possibly leading to mortality outbreaks in ponds, Ifremer has been conducting a research program since 2003 under the DESANS project (2003-2006) and the present DEDUCTION project, equally funded by the South and North Provinces and by the Government... |
| Tipo: Text |
Palavras-chave: Shrimp farming; Technical and scientific support; Vibriosis; Water quality; Pathology; Ecophysiology; Genetics; Zoosanitary monitoring and procedures; Multifactorial and multidisciplinary approach. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00143/25438/23591.pdf |
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| Registros recuperados: 36 | |
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