Exposure to the Paralytic Shellfish Toxin Producer Alexandrium catenella Increases the Susceptibility of the Oyster Crassostrea gigas to Pathogenic Vibrios
|Author(s)||Abi-Khalil Celina1, Lopez-Joven Carmen1, Abadie Eric2, Savar Veronique3, Amzil Zouher3, Laabir Mohamed2, Rolland Jean-Luc1|
|Affiliation(s)||1 : Univ Montpellier, Univ Perpignan Via Domitia, Inst Francais Rech Exploitat Mer IFREMER,CNRS, Interact Hotes Pathogenes Environm IHPE UMR 5244, F-34095 Montpellier, France.
2 : Univ Montpellier, CNRS,IRD, Ctr MARine Biodivers Exploitat & Conservat MARBEC, Inst Francais Rech Exploitat Mer IFREMER,UMR 9190, F-34095 Montpellier, France.
3 : Inst Francais Rech Exploitat Mer IFREMER, Phycotoxines Lab, Iled Yeu St BP 21105, F-44311 Nantes 3, France.
|Source||Toxins (2072-6651) (Mdpi Ag), 2016-01 , Vol. 8 , N. 24 , P. 1-14|
|WOS© Times Cited||5|
|Keyword(s)||harmful algae, environment, interaction, pathogens, defense, paralytic shellfish toxin|
|Abstract||The multifactorial etiology of massive Crassostrea gigas summer mortalities results from complex interactions between oysters, opportunistic pathogens and environmental factors. In a field survey conducted in 2014 in the Mediterranean Thau Lagoon (France), we evidenced that the development of the toxic dinoflagellate Alexandrium catenella, which produces paralytic shellfish toxins (PSTs), was concomitant with the accumulation of PSTs in oyster flesh and the occurrence of C. gigas mortalities. In order to investigate the possible role of toxic algae in this complex disease, we experimentally infected C. gigas oyster juveniles with Vibrio tasmaniensis strain LGP32, a strain associated with oyster summer mortalities, after oysters were exposed to Alexandrium catenella. Exposure of oysters to A. catenella significantly increased the susceptibility of oysters to V. tasmaniensis LGP32. On the contrary, exposure to the non-toxic dinoflagellate Alexandrium tamarense or to the haptophyte Tisochrysis lutea used as a foraging alga did not increase susceptibility to V. tasmaniensis LGP32. This study shows for the first time that A. catenella increases the susceptibility of Crassostrea gigas to pathogenic vibrios. Therefore, in addition to complex environmental factors explaining the mass mortalities of bivalve mollusks, feeding on neurotoxic dinoflagellates should now be considered as an environmental factor that potentially increases the severity of oyster mortality events.|