Virulence of Ostreid herpesvirus 1 μVar in sea water at 16 °C and 25 °C

• Published in: Aquaculture
• Main Authors: Martenot, Claire, Denéchère, Lucie, Hubert, Paul, Metayer, Laetitia, Oden, Elise, Trancart, Suzanne, Travaillé, Emmanuelle, Houssin, Maryline
• Other Authors: LABÉO, Pôle d’analyses et de recherche de Normandie (LABÉO), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Interactions Cellules Organismes Environnement (ICORE), Normandie Université (NU)-Normandie Université (NU)-CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Tumorothèque de Caen Basse-Normandie (TCBN)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Herpesvirus; Real-time RT PCR; Crassostrea gigas; Injection challenge; [SDV]Life Sciences [q-bio]
• Online Access: https://normandie-univ.hal.science/hal-03402163; https://doi.org/10.1016/j.aquaculture.2015.01.012

International audience The Ostreid herpesvirus 1 (OsHV-1) is associated with the mortality of young oysters Crassostrea gigas in France. The virus could infect different marine bivalve species and OsHV-1 DNA was previously detected in crustacean, marine gastropod, and sediment. Nevertheless, the effect of the temperature on the stability of infectious viral particles in sea water remains unpublished. During a mortality event, dead oysters may release virus in the sea water such as free viral particles, viral particles included in cells or attached to a support like plankton, suspended particulate matters, and microalgae. Oysters placed around the infectious source may filtrate the virus and then be infected by OsHV-1. In the present study, we investigated the OsHV-1 μVar virulence in sea water at 16 °C and 25 °C. Filtered infected tissue homogenates were kept at 16 °C or 25 °C prior to injection challenge of uninfected spats. A real-time reverse transcription PCR targeting the OsHV-1 polymerase gene has been developed to confirm the death cause oysters collected during the experiment. The RNA detection of herpesvirus in their hosts is a sign of viral replication and indicates that the virus is certainly infectious. Results showed that the OsHV-1 μVar remained infectious and induced mortality after 33 h at 25 °C and 54 h at 16 °C in controlled conditions. The OsHV-1 μVar is thus able to persist in sea water and high temperatures seem to reduce its infectivity. However, the OsHV-1 μVar virulence may be modulated by biological, physical and chemical factors which are present in sea water.