Temperature modulate disease susceptibility of the Pacific oyster Crassostrea gigas and virulence of the Ostreid herpesvirus type 1

• Published in: Fish & Shellfish Immunology
• Main Authors: Delisle, Lizenn, Petton, Bruno, Burguin, Jean François, Morga, Benjamin, Corporeau, Charlotte, Pernet, Fabrice
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Génétique et Pathologie des Mollusques Marins, 17390 La Tremblade, France. (LGPMM), Santé, Génétique et Microbiologie des Mollusques (IFREMER SG2M), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), European Project: 678589,H2020,H2020-SFS-2015-2,VIVALDI(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: ACL; Temperature; Bivalve; Health; Mortality risk; Marine disease; Virulence; envir; psy; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.1016/j.fsi.2018.05.056; https://hal.archives-ouvertes.fr/hal-02619276/file/Delisle_etal_FSI_2018.pdf; https://hal.archives-ouvertes.fr/hal-02619276

International audience Temperature triggers marine diseases by changing host susceptibility and pathogen virulence. Oyster mortalities associated with the Ostreid herpesvirus type 1 (OsHV-1) have occurred seasonally in Europe when the seawater temperature range reaches 16–24 °C. Here we assess how temperature modulates oyster susceptibility to OsHV-1 and pathogen virulence. Oysters were injected with OsHV-1 suspension incubated at 21 °C, 26 °C and 29 °C and were placed in cohabitation with healthy oysters (recipients) at these three temperatures according to a fractional factorial design. Survival was followed for 14 d and recipients were sampled for OsHV-1 DNA quantification and viral gene expression. The oysters were all subsequently placed at 21 °C to evaluate the potential for virus reactivation, before being transferred to oyster farms to evaluate their long-term susceptibility to the disease. Survival of recipients at 29 °C (86%) was higher than at 21 °C (52%) and 26 °C (43%). High temperature (29 °C) decreased the susceptibility of oysters to OsHV-1 without altering virus infectivity and virulence. At 26 °C, the virulence of OsHV-1 was enhanced. Differences in survival persisted when the recipients were all placed at 21 °C, suggesting that OsHV-1 did not reactivate. Additional oyster mortality followed the field transfer, but the overall survival of oysters infected at 29 °C remained higher.