Taxinomie et épidémiologie moléculaires du parasite Marteilia refringens Grizel et al. 1974 : intérêt pour la gestion du risque sanitaire en conchyliculture

Infectious diseases are currently recognised as a major limiting factor to development and sustainability of aquaculture of molluscs. The study is focused on the European flat oyster, Ostrea edulis and its paramyxean parasite Marteilia refringens. Results are contributing to the prevention of risk associated to infected stocks imports from endemic zones, by developing molecular diagnostic tools that are specific, sensible and reliable. Phylogeny and taxonomy of Marteilia refringens, previously impeded by microscopy limits, were clarified by sequencing the rDNA SSU, small sub-unit in the rRNA gene cluster. These new insights have practical implications discussed in a pragmatic polyphasic approach involving pathology and epidemiology. This approach led us to distinguish Marteilia refringens, parasite of flat oysters, Ostrea edulis, from Marteilia maurini, parasite of mussels, Mytilus edulis et M. galloprovincialis. A conceptual model of genic flux between the two species, in an alloxenic speciation process, is proposed as a way to investigate role of mussels in dissemination and propagation of marteilioisis caused by Marteilia refringens.