|
|
|
| Registros recuperados: 73 | |
|
|
| Mai, T.; Tintillier, Florent; Lucasson, Aude; Moriou, C.; Bonno, E.; Petek, S.; Magre, Kevin; Al Mourabit, A.; Saulnier, Denis; Debitus, C.. |
| Sponges are a rich source for investigation of bioactive small molecules. They have been mostly investigated for the search of new pharmacological models or therapeutic agents for the treatment of human diseases. Micro-organisms can also represent a virulent pathogen for marine invertebrates such as sponges, which need to protect themselves against these microbes. Sponges' self defence mechanisms involving dialogue molecules thus represent a pertinent research track for potent anti-infective and anti-biofilm activities such as quorum sensing inhibitors (QSIs). The investigation of the QSI crude extract of Leucetta chagosensis Dendy, 1863 led to the isolation of three new alkaloids, isonaamine D, di-isonaamidine A and leucettamine D, along with the known... |
| Tipo: Text |
Palavras-chave: Biofouling; Leucetta chagosensis; Leucettamine; Naamidine; Naamine; Quorum sensing; Quorum sensing inhibitors; Sponges; Vibrio harveyi. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38597/37189.pdf |
| |
|
|
| Suquet, Marc; Agogue, Julie; Brizard, Raphael; Haffray, Pierrick; Labbe, Catherine; Le Coz, Jean-rene; Pepin, Jean-francois; Rault, Paul; Saulnier, Denis. |
| Ce rapport fait état d'une étude réalisée au laboratoire de Génétique et Pathologie de l'IFREMER dans le cadre de l'analyse d'épisodes de mortalité anormale survenue en écloserie privée de crevettes pénéides. Plusieurs hypothèses ont été avancées. La présence de Vibrio harveyi a amené à constituer une collection de 40 souches à partir desquelles une identification bactériologique a été effectuée. Elle montre en effet une dominance de souches appartenant à un groupe homogène de Vibrio harveyi. La technique de ribotypage (digestion d'ADN génomique, transfert de Southem-blot et hybridation avec une sonde spécifique) est alors mise en place. Plusieurs difficultés techniques ont ralenti l'analyse et n'ont donc pas permis d'avoir des résultats assez avancés pour... |
| Tipo: Text |
Palavras-chave: Huître creuse; Crassostrea gigas; Tétraploïdes; Sperme; Conservation; Diagnostic zoo-sanitaire; Flore bactérienne; Herpès virus.. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00304/41554/40762.pdf |
| |
|
|
| Tintillier, Florent; Moriou, Céline; Petek, Sylvain; Fauchon, Marilyne; Hellio, Claire; Saulnier, Denis; Ekins, Merrick; Hooper, John N. A.; Al-mourabit, Ali; Debitus, Cecile. |
| Four new brominated tyrosine metabolites, aplyzanzines C–F (1–4), were isolated from the French Polynesian sponge Pseudoceratina n. sp., along with the two known 2-aminoimidazolic derivatives, purealidin A (5) and 6, previously isolated, respectively, from the sponges Psammaplysilla purpurea and Verongula sp. Their structures were assigned based on the interpretation of their NMR and HRMS data. The compounds exhibited quorum sensing inhibition (QSi) and antifouling activities against several strains of bacteria and microalgae. To our knowledge, the QSi activity of this type of bromotyrosine metabolite is described here for the first time. |
| Tipo: Text |
Palavras-chave: Sponge; Pseudoceratina; Quorum sensing inhibitory activity; Antifouling; Verongiida; Bromotyrosine. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74200/73825.pdf |
| |
|
|
| Cardona, Emilie; Saulnier, Denis; Lorgeoux, Benedicte; Chim, Liet; Gueguen, Yannick. |
| This study compares the antioxidant and antimicrobial transcriptional expression of blue shrimps reared according to two different systems, BioFloc Technology (BFT) and Clear sea Water (CW) and their differential responses when facing an experimental sublethal hydrogen peroxide stress. After 30 days of rearing, juvenile shrimps were exposed to H2O2 stress at a concentration of 30 ppm during 6 hours. The oxidative stress caused by H2O2 was examined in the digestive glands of the shrimp, in which antioxidant enzyme (AOE) and antimicrobial peptide (AMP) gene expression were analysed by quantitative real-time PCR. Results showed that rearing conditions did not affect the expression of genes encoding AOEs or AMPs. However, H2O2 stress induced a differential... |
| Tipo: Text |
Palavras-chave: Biofloc; Shrimps; Antimicrobial peptides; Antioxidant enzymes. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38116/36269.pdf |
| |
|
|
| De Decker, Sophie; Normand, Julien; Saulnier, Denis; Pernet, Fabrice; Castagnet, Sophie; Boudry, Pierre. |
| Several Vibrio species are known to be pathogenic to the Pacific oyster Crassostrea gigas. Survival varies according to pathogen exposure and high mortality events usually occur in summer during gametogenesis. In order to study the effects of gametogenetic status and ploidy (a factor known to affect reproduction allocation in oysters) on vibriosis survival, we conducted two successive experiments. Our results demonstrate that a common bath challenge with pathogenic Vibrio splendidus and Vibrio aestuarianus on a mixture of mature, spawning and non-mature oysters can lead to significant mortality. Previous bath challenges, which were done using only non-mature oysters, had not produced mortality. Immunohisto-chemical analyses showed the affinity of Vibrio... |
| Tipo: Text |
Palavras-chave: Experimental vibriosis; Crassostrea gigas; Vibrio; Survival distribution function; Triploidy; Reproductive effort. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00030/14108/11368.pdf |
| |
|
|
| Gagnaire, Beatrice; Gay, Melanie; Huvet, Arnaud; Daniel, Jean-yves; Saulnier, Denis; Renault, Tristan. |
| To assess the impact of pollution induced by pesticides on Pacific oyster, Crassostrea gigas, health in France, in vivo effects of combined pesticide exposure and bacterial challenge on cell activities and gene expression in hemocytes were tested using flow cytometry and real-time PCR. As a first step, an in vivo model of experimental contamination was developed. Pacific oysters were exposed to a mixture of eight pesticides (atrazine, glyphosate, alachlor, metolachlor, fosetyl-alumimium, terbuthylazine, diuron and carbaryl) at environmentally relevant concentrations over a 7-day period. Hemocyte parameters (cell mortality, enzyme activities and phagocytosis) were monitored using flow cytometry and gene expression was evaluated by real-time PCR (RT-PCR).... |
| Tipo: Text |
Palavras-chave: Gene expression; Flow cytometry; Vibrio splendidus; Pathogenesis; Phagocytosis; Hemocyte; Pesticides; Bivalve immunity; Crassostrea gigas; Pacific oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3022.pdf |
| |
|
| |
|
|
| Reverter, Miriam; Saulnier, Denis; David, Rarahu; Bardon-albaret, Agnes; Belliard, Corinne; Tapissier-bontemps, Nathalie; Lecchini, David; Sasal, Pierre. |
| The emerging orbicular batfish (Platax orbicularis) aquaculture is the most important fish aquaculture industry in French Polynesia. However, bacterial infections are causing severe mortality episodes. Therefore, there is an urgent need to find an effective management solution. Besides the supplying difficulty and high costs of veterinary drugs in French Polynesia, batfish aquaculture takes place close to the coral reef, where use of synthetic persistent drugs should be restricted. Medicinal plants and bioactive algae are emerging as a cheaper and more sustainable alternative to chemical drugs. We have studied the effect of local Polynesian plants and the local opportunistic algae Asparagopsis taxiformis on batfish when orally administered. Weight gain and... |
| Tipo: Text |
Palavras-chave: Orbicular batfish; Asparagopsis taxiformis; Immunostimulant; Lysozyme G; Transforming growth factor; Relative gene expression. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00350/46155/45853.pdf |
| |
|
|
| Luna-acosta, Andrea; Saulnier, Denis; Pommier, Mylene; Haffner, Philippe; De Decker, Sophie; Renault, Tristan; Thomas-guyon, Helene. |
| Phenoloxidases (POs) are a group of copper proteins including tyrosinase, catecholase and laccase. In several insects and crustaceans, antibacterial substances are produced through the PO cascade, participating in the direct killing of invading microorganisms. However, although POs are widely recognised as an integral part of the invertebrate immune defence system, experimental evidence is lacking that these properties are conserved in molluscs, and more particularly in the Pacific oyster Crassostrea gigas. In the present study, Vibrio splendidus LGP32 and Vibrio aestuarianus 02/041 growths were affected, after being treated with C. gigas haemocyte lysate supernatant (HLS), and either a common substrate of POs, l-3,4-dihydroxyphenylalanine (l-DOPA), to... |
| Tipo: Text |
Palavras-chave: Phenoloxidases; Antibacterial activity; Vibrio; Bivalve; Immunity. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00045/15598/13001.pdf |
| |
|
|
| Saulnier, Denis; De Decker, Sophie; Haffner, Philippe; Cobret, Laetitia; Robert, Maeva; Garcia, Celine. |
| A 4-year bacteriological survey (2003-2007) of four molluscs cultivated in France and faced with mortality episodes was performed by the French shellfish pathology network. The more abundant bacteria isolated during 92 mortality episodes, occurring mainly in Pacific oyster Crassostrea gigas, were identified by genotyping methods. It allowed us both to confirm the representativeness of Vibrio splendidus and Vibrio aestuarianus bacterial strains and to identify both a large number of Vibrio harveyi-related strains mainly detected during 2007 oyster mortality outbreaks and to a lesser extent bacterial strains identified as Shewanella colwelliana. Because metalloprotease has been reported to constitute a virulence factor in a few Vibrio strains pathogenic for... |
| Tipo: Text |
|
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6974.pdf |
| |
|
|
| Rouze, Heloise; Lecellier, Gael; Saulnier, Denis; Berteaux-lecellier, Veronique. |
| Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14-month-long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the... |
| Tipo: Text |
Palavras-chave: Coral disease; Dynamic; Resistance; Symbiodinium assemblages; Vibrio. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00307/41848/41080.pdf |
| |
|
|
| 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 |
|
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6632.pdf |
| |
|
|
| Mai, Tepoerau; Toullec, Jordan; Van Wynsberge, Simon; Besson, Marc; Soulet, Stephanie; Petek, Sylvain; Aliotti, Emmanuelle; Ekins, Merrick; Hall, Kathryn; Erpenbeck, Dirk; Lecchini, David; Beniddir, Mehdi A.; Saulnier, Denis; Debitus, Cecile. |
| Marine natural products isolated from the sponge Fascaplysinopsis cf reticulata, in French Polynesia, were investigated as an alternative to antibiotics to control pathogens in aquaculture. The overuse of antibiotics in aquaculture is largely considered to be an environmental pollution, because it supports the transfer of antibiotic resistance genes within the aquatic environment. One environmentally friendly alternative to antibiotics is the use of quorum sensing inhibitors (QSIs). Quorum sensing (QS) is a regulatory mechanism in bacteria which control virulence factors through the secretion of autoinducers (AIs), such as acyl-homoserine lactone (AHL) in gram-negative bacteria. Vibrio harveyi QS is controlled through three parallel pathways: HAI-1, AI-2,... |
| Tipo: Text |
Palavras-chave: Porifera; Marine natural products; Quorum sensing inhibitors; Antibiotic; Fascaplysinopsis cf reticulata. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00598/71052/69366.pdf |
| |
|
|
| Cochennec-laureau, Nathalie; Montagnani, Caroline; Saulnier, Denis; Fougerouse, Angelique; Levy, Peva; Lo, Cedrik. |
| Pearl oyster grafting is a complex surgical operation that should lead to pearl formation after approximately eighteen months. Although this technique has been used for many years in French Polynesia, the grafting process is still not standardised. While studies have been carried out in order to improve graft performance and yield, these remain highly variable due to post-grafting mortality, nucleus rejection and unreliable pearl quality, all of which constrain pearl farm profitability. The present study uses histological analysis to monitor oysters that either rejected or retained their nuclei. Both groups of oysters are compared in terms of evolution of the graft, which could influence retention, and the development of a pearl sac in cases where grafting... |
| Tipo: Text |
Palavras-chave: Grafting process; Pearl formation; Pearl oyster; Pteriidae; Pinctada margaritifera. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11288/7823.pdf |
| |
|
|
| Lopez Flores, L; Suarez Santiago, V; Longet, D; Saulnier, Denis; Chollet, Bruno; Arzul, Isabelle. |
| Bonamia ostreae is a protozoan parasite that infects the European flat oyster Ostrea edulis, causing systemic infections and resulting in massive mortalities in populations of this valuable bivalve species. In this work, we have characterized B. ostreae actin genes and used their sequences for a phylogenetic analysis. Design of different primer sets was necessary to amplify the central coding region of actin genes of B. ostreae. Characterization of the sequences and their amplification in different samples demonstrated the presence of 2 intragenomic actin genes in B. ostreae, without any intron. The phylogenetic analysis placed B. ostreae in a clade with Minchinia tapetis, Minchinia teredinis and Haplosporidium costale as its closest relatives, and... |
| Tipo: Text |
Palavras-chave: Molecular phylogeny; Actin gene; Ostrea edulis parasite; Bonamia ostreae. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3562.pdf |
| |
|
| |
|
|
| Cochennec-laureau, Nathalie; Levy, Peva; Saulnier, Denis; Fougerouse, Angelique. |
| L’importance socio-économique de l’activité perlière justifie que le Service de la Perliculture mette en place un réseau de surveillance pathologique de l’huître perlière Pinctada margaritifera en Polynésie française. Les objectifs de ce réseau sont de prévenir l’introduction ou l’apparition d’agents infectieux, de prévenir leur propagation à l’intérieur d’une zone d’élevage, d’étudier les moyens de limiter leur impact, de surveiller leur évolution et enfin de garantir les échanges entre les zones d’élevage. Cette première année a permis d’élaborer le schéma de fonctionnement du réseau et de vérifier sa faisabilité. Cinq zones de prélèvements ont été définies en fonction de critères d’accessibilité à la zone et de facilité d’acheminement des échantillons,... |
| Tipo: Text |
|
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00168/27886/26141.pdf |
| |
|
|
| Chim, Liet; Cardona, Emilie; Lorgeoux, Benedicte; Gueguen, Yannick; Saulnier, Denis; Goguenheim, Jean; Wantiez, Laurent; Cahu, Chantal. |
| Shrimp farming in New-Caledonia faces up to difficulties. A fluctuating quality of broodstock prevents sustainable production of larvae in quantity and quality. The traditional extensive rearing method of broodstock in outdoor earthen ponds used in New Caledonia raises several issues: poor water quality control and biosecurity. Therefore it is fundamental to modify the broodstock culture strategy in order to achieve an easier water quality management and maximal biosecurity. Biofloc technology (BFT) offers easier water quality management, higher natural productivity, higher level of biosecurity, and could be a good alternative. Since 2011 a R&D program started under the supervision of IFREMER in New Caledonia and French Polynesia in order to study and... |
| Tipo: Text |
|
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00250/36084/34635.pdf |
| |
|
|
| Travers, Marie-agnes; Mersni Achour, Rachida; Haffner, Philippe; Tourbiez, Delphine; Cassone, Anne-laure; Morga, Benjamin; Doghri, Ibtissem; Garcia, Celine; Renault, Tristan; Fruitier-arnaudin, Ingrid; Saulnier, Denis. |
| Nine dominant bacterial isolates were obtained from different batches of Crassostrea gigas spat experiencing high mortality rates in a French experimental hatchery/nursery in 2007. Using phenotypic analysis combined with multilocus sequence analysis, the isolates were shown to be genetically close to the Vibrio tubiashii type strain. Based on (1) analyses of the recA gene sequences; (2) the results of DNA–DNA hybridization assays between 07/118 T2 (LMG 27884 = CECT 8426), which is a representative strain, and the V. tubiashii type strain (69%); and (3) phenotypic traits, the bacteria were classified in a group close to American V. tubiashii strain. Its virulence (70% of mortalities) and the toxicity of the extracellular products of 07/118 T2 was... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas Pathogenicity Extracellular products Polyphasic approach; Real time PCR. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00189/30028/28743.pdf |
| |
|
|
| Latchere, Oihana; Mehn, Vincent; Gaertner-mazouni, Nabila; Le Moullac, Gilles; Fievet, Julie; Belliard, Corinne; Cabral, Philippe; Saulnier, Denis. |
| Environmental parameters, such as food level and water temperature, have been shown to be major factors influencing pearl oyster shell growth and molecular mechanisms involved in this biomineralization process. The present study investigates the effect of food level (i.e., microalgal concentration) and water temperature, in laboratory controlled conditions, on the last stages of pearl mineralization in order to assess their impact on pearl quality. To this end, grafted pearl oysters were fed at different levels of food and subjected to different water temperatures one month prior to harvest to evaluate the effect of these factors on 1) pearl and shell deposition rate, 2) expression of genes involved in biomineralization in pearl sacs, 3) nacre... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/54007/55223.pdf |
| |
| Registros recuperados: 73 | |
|
|
|
