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| Bruto, Maxime; Labreuche, Yannick; James, Adele; Piel, Damien; Chenivesse, Sabine; Petton, Bruno; Polz, Martin F.; Le Roux, Frederique. |
| Diseases of marine animals caused by bacteria of the genus Vibrio are on the rise worldwide. Understanding the eco-evolutionary dynamics of these infectious agents is important for predicting and managing these diseases. Yet, compared to Vibrio infecting humans, knowledge of their role as animal pathogens is scarce. Here we ask how widespread is virulence among ecologically differentiated Vibrio populations, and what is the nature and frequency of virulence genes within these populations? We use a combination of population genomics and molecular genetics to assay hundreds of Vibrio strains for their virulence in the oyster Crassostrea gigas, a unique animal model that allows high-throughput infection assays. We show that within the diverse Splendidus... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00452/56370/57967.pdf |
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| Petton, Bruno; Bruto, Maxime; James, Adele; Labreuche, Yannick; Alunno-bruscia, Marianne; Le Roux, Frederique. |
| Successive disease outbreaks in oyster (Crassostrea gigas) beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 µvar) and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 µvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF) oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe... |
| Tipo: Text |
Palavras-chave: Pacific oysters; Summer mortality; Herpes virus; Vibrio pathogenicity; Experimental infection. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38220/36377.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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| 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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| 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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| 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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| 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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