Oyster vibrio interactions and in situ monitoring of oyster health status.

Transcription

1 Oyster vibrio interactions and in situ monitoring of oyster health status. J. de Lorgeril R. D. Rosa M. Duperthuy E. Bachère D. Destoumieux Garzón Ecology of coastal marine systems CNRS, Ifremer, IRD, University of Montpellier

2 QuickTime et un décompresseur TIFF (non compressé) sont requis pour visionner cette image. QuickTime et un décompresseur TIFF (non compressé) sont requis pour visionner cette image. Vibrios in the environment Over 80 species of Vibrio are part of the normal flora of the surface waters on earth. They are associated to a broad diversity of host

3 Vibrios cause major human diseases At least ten Vibrio species cause disease in humans and new Vibrio species each year are emerging as a public health threat (Daniels & Shafaie, 2000) (Igbinosa & Okoh, 2008) deaths in GB deaths in Haiti

4 Vibrios are responsible for major diseases in aquaculture Fish Morone americana infected by Vibrio anguillarum (hemorragy) (Austin & Austin, 2007) Shrimp Litopenaeus stylirostris Infected with Vibrio nigripulchritudo Vibrios are associated to major infectious events in bivalve molluscs (Paillard et al., 2004; Garnier et al., 2007). Clam infected with Vibrio tapetis (brown ring disease)

5 Global warming associated to new Vibrio diseases in humans and animals Ocean warming Increase in Vibrio species Emergence of diseases (Lipp et al., 2002; Tantillo et al., 2004)

6 Aquaculture development and disease emergence Aquaculture is the fastest growing food industry world wide Aquaculture accounts for ~ 30% of world fish production It is expected to contribute with 65% of seafood in 2030 (FAO, 2010) Intensive cultures Transfert of animals Stress Transfert of pathogens Emergence of infectious diseases

7 Sustainability of aquaculture Increased infectious threat Prevention and disease control Global warming Intensive aquaculture Animals with optimized health status Modify cultural practices Develop selective breeding Explore the genetic basis of improved immunocompetence

8 Infectious threat on oyster farming Recurrent and massive mortalities of oyster juveniles in the warm season A multifactorial disease: Pathogens: herpes OsHV1 + Vibrios Environment: Sea water temperature over 16 C Oyster genetics and physiology

9 Infectious threat on oyster farming Strains of Vibrio splendidus and Vibrio aestuarianus are the main bacterial pathogens found in moribond oysters.

10 Research programs on oyster Vibrio interactions Vibrio V. aestuarianus Labreuche et al. DCI (2006) Inhibition of phagocytosis Duperthuy et al. PNAS (2011)

11 A gene signature specific for a virulent Vibrio infection Virulent V. splendidus V. aestuarianus vs. Avirulent V. tasmaniensis Ctrl + Avir Vir Tags 1610 expressed ESTs Annotated 180 candidate ESTs virulence vs. avirulence de Lorgeril et al. PlosOne (2011)

12 Exploration of the qpcr signature according to in situ mortalities Lagoon spats adults 2011 mortalities: Sea 100% mortalities / spats OsHV1 + V. splendidus +

13 Exploration of the qpcr signature according to in situ mortalities A B C D E Hierarchical clustering of qpcr data Spats / sea Spats / Lagoon Before mortalities Adults / lagoon during spat mortalities Spats / lagoon during mortalities Overexpressed independently of survival Efficient response Repressed in susceptible animals

14 A gene signature predictive of oyster capacity to survive a vibriosis Able vs. V. splendidus V. aestuarianus Tags Disable 1049 expressed ESTs 280 candidate ESTs 14 marker genes PLS component t[2]: R²Y = NS Basal levels of gene expression PLS component t[1]: R²Y = 0,596 Alive Dead Individual analysis on 45 animals of each phenotype (able / disable) Rosa RD, et al., 2012 BMC Genomics

15 Exploration of the qpcr signature according to selective breeding Resistant & Susceptible lineages (2001 mortality events) Resistant & Non-selected lineages (2009 mortality events) Susc. Non Selected 57 / 93 Resist. 23 / 91 Resistant

16 Future studies and expected applications Validation Validate in situ on large cohorts of oysters Selective breeding Test the heritabilty of the gene signature Prevention Monitoring of oyster health status

17 Contributors: Julien de Lorgeril, PhD* Rafael Da Rosa, PhD* Evelyne Bachère, PhD* Marylise Duperthuy, PhD Delphine Destoumieux Garzon, PhD Thanks Fundings :