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| Mersni-achour, Rachida; Ben Cheikh, Yosra; Pichereau, Vianney; Doghri, Ibtissem; Etien, Cedric; Degremont, Lionel; Saulnier, Denis; Fruitier-arnaudin, Ingrid; Travers, Marie-agnes. |
| Vibrio tubiashii is a marine pathogen isolated from larval and juvenile bivalve molluscs causing bacillary necrosis. Recent studies demonstrated the isolation of this species in a French experimental hatchery/nursery affecting Crassostrea gigas spat in 2007. Here, using larvae of C. gigas as an interaction model, we showed that the French V. tubiashii is virulent to larvae and can cause bacillary necrosis symptoms with a LD50 about 2.3 × 103 cfu ml-1 after 24 h. Moreover, complete or GP- HPLC fractionated extracellular products (ECPs) of this strain appeared toxic to larvae. MS-MS analysis of the different ECPs fractions revealed the existence of an extracellular metalloprotease and other suspected virulence factors. This observation is also supported by... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00252/36367/34907.pdf |
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| Ben Cheikh, Yosra; Travers, Marie-agnes; Morga, Benjamin; Godfrin, Yoann; Rioult, Damien; Le Foll, Franck. |
| Bacterial isolates were obtained from mortality events affecting Mytilus edulis and reported by professionals in 2010-2013 or from mussel microflora. Experimental infections allowed the selection of two isolates affiliated to V. splendidus/V. hemicentroti type strains: a virulent 10/068 1T1 (76,6% and 90% mortalities in 24h and 96h) and an innocuous 12/056 M24T1 (0% and 23,3% in 24h and 96h). These two strains were GFP-tagged and validated for their growth characteristics and virulence as genuine models for exposure. Then, host cellular immune responses to the microbial invaders were assessed. In the presence of the virulent strain, hemocyte motility was instantaneously enhanced but markedly slowed down after 2h exposure. By contrast, hemocyte velocity... |
| Tipo: Text |
Palavras-chave: Innate immunity; Molluscs; Cell-mediated immune response; Bacterial infections; Green fluorescent protein. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00302/41336/40522.pdf |
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| Ben Cheikh, Yosra; Travers, Marie-agnes; Le Foll, Frank. |
| The pathogenic strain V. splendidus 10/068 1T1 has previously been reported for its virulence to the blue mussel and for its capacity to alter immune responses. In this study, we expanded the knowledge on hemocyte-pathogen interactions by using in vitro and in vivo assays. V. splendidus 10/068 1T1 severely inhibited cell adhesion and acidic vacuole formation unlike the innocuous phylogenetically related V. splendidus 12/056 M24T1 which had no effect on these cell functions. Furthermore, the virulent bacteria decreased hemocyte viability (59% of viability after 24 h). Infection dynamics were explored by using a model based on water tank cohabitation with septic mussels infected by GFP-tagged V. splendidus 10/068 1T1. Experimental infections were... |
| Tipo: Text |
Palavras-chave: Innate immunity; Bivalves; Vibrio; Infection; Experimental model; Hemocyte. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00400/51136/53772.pdf |
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