Interaction between toxic dinoflagellate Alexandrium catenella exposure and disease associated with herpesvirus OsHV-1μVar in Pacific oyster spat Crassostrea gigas
|Author(s)||Lassudrie Malwenn1, Soudant Philippe1, Nicolas Jean-Louis2, Fabioux Caroline1, Lambert Christophe1, Miner Philippe2, Le Grand Jacqueline3, Petton Bruno3, Hegaret Helene1|
|Affiliation(s)||1 : Inst Univ Europeen Mer, UMR CNRS UBO IRD IFREMER 6539, Lab Sci Environm Marin LEMAR, F-29280 Plouzane, France.
2 : IFREMER, Lab Sci Environm Marin LEMAR, IRD,CS 10070, Ctr Bretagne,ZI Pointe du Diable,CNRS,UMR UBO 653, F-29280 Plouzane, France.
3 : IFREMER, Lab Sci Environm Marin LEMAR, IRD, CNRS,UMR UBO 6539, F-29840 Argenton En Landunvez, France.
|Source||Harmful Algae (1568-9883) (Elsevier Science Bv), 2015-05 , Vol. 45 , P. 53-61|
|WOS© Times Cited||22|
|Keyword(s)||Crassostrea gigas, OsHV-1 mu Var, Harmful algal blooms, Alexandrium, Host-pathogen interaction, PST accumulation|
|Abstract||Blooms of toxic dinoflagellates can co-occur with mass mortality events associated with herpesvirus OsHV-1 μVar infection that have been decimating Pacific oyster Crassostrea gigas spat and juveniles every summer since 2008 in France. This study investigated the possible effect of a harmful dinoflagellate, Alexandrium catenella, a producer of Paralytic Shellfish Toxins (PSTs), upon the oyster spat–herpesvirus interaction. Oyster spat from a hatchery were challenged by cohabitation with oysters contaminated in the field with OsHV-1 μVar and possibly other pathogens. Simultaneously, the oysters were exposed to cultured A. catenella. Infection with OsHV-1 μVar and PST accumulation were measured after 4 days of experimental exposure.Exposure to Alexandrium catenella modified the host–pathogen interaction by reducing prevalence of OsHV-1 μVar infection. In addition, oysters challenged with OsHV-1 μVar and possibly other pathogens from the environment accumulated smaller amounts of PSTs than unchallenged oysters. Three possible mechanisms are suggested by these results: (i) possible direct interactions between A. catenella and herpesvirus (or associated pathogens) could reduce viral transmission and algal availability for oyster consumption; (ii) oyster feeding behavior or digestive functions may have been altered, thus decreasing both uptake of viral particles and consumption or digestion of toxic algae and consequent toxin accumulation; (iii) immuno-activation by A. catenella could enhance defense efficiency against OsHV-1 μVar infection. These findings suggest further research on relationships between OsHV-1 μVar and toxic dinoflagellates and their combined effects upon disease transmission and proliferation processes, as well as on oyster physiological and immunological involvement in this complex, tripartite interaction.|