Fine-scale temporal dynamics of herpes virus and vibrios in seawater during a polymicrobial infection in the Pacific oyster Crassostrea gigas

• Published in: Diseases of Aquatic Organisms
• Main Authors: Petton, Bruno, De Lorgeril, J., Mitta, G., Daigle, G, Pernet, Fabrice, Alunno-Bruscia, Marianne
• 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 (IFREMER), Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Groupe Interdisciplinaire de Recherche en Éléments Finis Québec (GIREF), Université Laval Québec (ULaval)-Centre de Recherches Mathématiques Montréal (CRM), Université de Montréal (UdeM)-Université de Montréal (UdeM), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER), ANR-14-CE19-0023,DECIPHER,Déchiffrage des maladies multifactorielles: cas des mortalités de l'huître(2014), ANR-12-AGRO-0001,GIGASSAT,Adaptation des écosystèmes ostréicoles au changement global(2012), ANR-13-ADAP-0007,OPOPOP,Emergence de pathogènes opportunistes d'huîtres dans des populations naturelles de Vibrio(2013), ANR-16-CE32-0008,REVENGE,L'huître comme niche de l'évolution et l'émergence de vibrios pathogènes(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Aquaculture; Bivalve; Epidemiology; Health; Polymicrobial disease; OSHV-1; Pacific oyster mortality syndrome; POMS; ACL; envir; demo; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.3354/dao03384; https://hal.archives-ouvertes.fr/hal-02163426

International audience The Pacific oyster Crassostrea gigas is currently being impacted by a polymicrobial disease that involves early viral infection by ostreid herpesvirus-1 (OsHV-1) followed by a secondary bacterial infection leading to death. A widely used method of inducing infection consists of placing specific pathogen-free oysters ('recipients') in cohabitation in the laboratory with diseased oysters that were naturally infected in the field ('donors'). With this method, we evaluated the temporal dynamics of pathogen release in seawater and the cohabitation time necessary for disease transmission and expression. We showed that OsHV-1 and Vibrio spp. in the seawater peaked concomitantly during the first 48 h and decreased thereafter. We found that 1.5 h of cohabitation with donors was enough time to transmit pathogens to recipients and to induce mortality later, reflecting the highly contagious nature of the disease. Finally, mortality of recipients was associated with increasing cohabitation time with donors until reaching a plateau at 20%. This reflects the cumulative effect of exposure to pathogens. The optimal cohabitation time was 5-6 d, the mortality of recipients occurring 1-2 d earlier.