title: Effect of experimental exposure to differently virulent Aphanomyces astaci strains on the immune response of the noble crayfish Astacus astacus.
abstract: European crayfish are sensitive to the crayfish plague pathogen, Aphanomyces astaci, carried by North American crayfish species due to their less effective immune defence mechanisms against this disease. During a controlled infection experiment with a susceptible crayfish species Astacus astacus using three A. astaci strains (representing genotype groups A, B, and E), we investigated variation in their virulence and in crayfish immune defence indicators (haemocyte density, phenoloxidase activity, and production of reactive oxygen species). Experimental crayfish were exposed to two dosages of A. astaci spores (1 and 10 spores mL(-1)). The intensity and timing of the immune response differed between the strains as well as between the spore concentrations. Stronger and faster change in each immune parameter was observed in crayfish infected with two more virulent strains, indicating a relationship between crayfish immune response and A. astaci virulence. Similarly, the immune response was stronger and was observed earlier for the higher spore concentration. For the first time, the virulence of a strain of the genotype group E (isolated from Orconectes limosus) was experimentally tested. Total mortality was reached after 10 days for the two higher spore dosages (10 and 100 spores mL(-1)), and after 16 days for the lowest (1 spore mL(-1)), revealing equally high and rapid mortality as caused by the genotype group B (from Pacifastacus leniusculus). No mortality occurred after infection with genotype group A during 60 days of the experimental trial.
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipe: Ecologie, Evolution, Symbiose, Université de Poitiers, UMR CNRS 7267, 5 rue Albert Turpin, F-86073 Poitiers Cedex 9, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Becking
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, Prague 2 CZ-12844, Czech Republic.
authors.forename: Agata
authors.initials: A
authors.lastname: Mrugała
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipe: Ecologie, Evolution, Symbiose, Université de Poitiers, UMR CNRS 7267, 5 rue Albert Turpin, F-86073 Poitiers Cedex 9, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Delaunay
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, Prague 2 CZ-12844, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Svoboda
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipe: Ecologie, Evolution, Symbiose, Université de Poitiers, UMR CNRS 7267, 5 rue Albert Turpin, F-86073 Poitiers Cedex 9, France.
authors.forename: Maryline
authors.initials: M
authors.lastname: Raimond
authors.affiliation: Finnish Food Safety Authority Evira, OIE Reference Laboratory for Crayfish Plague, 70701 Kuopio, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Viljamaa-Dirks
authors.affiliation: Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, Prague 2 CZ-12844, Czech Republic.
authors.forename: Adam
authors.initials: A
authors.lastname: Petrusek
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipe: Ecologie, Evolution, Symbiose, Université de Poitiers, UMR CNRS 7267, 5 rue Albert Turpin, F-86073 Poitiers Cedex 9, France. Electronic address: frederic.grandjean@univ-poitiers.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Grandjean
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipe: Ecologie, Evolution, Symbiose, Université de Poitiers, UMR CNRS 7267, 5 rue Albert Turpin, F-86073 Poitiers Cedex 9, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Braquart-Varnier
mesh_terms: D000818:Animals; D044744:Aphanomyces / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D003400:Astacoidea / Q000276:immunology* / Q000469:parasitology; D001772:Blood Cell Count; D005838:Genotype; D006434:Hemocytes; D007113:Immunity, Innate; D014442:Monophenol Monooxygenase / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014774:Virulence
chemical_list: D017382:Reactive Oxygen Species; D014442:Monophenol Monooxygenase
keywords: Astacus astacus; Crayfish plague; Immune parameters; Mortality tests; Virulence