title: Prevalence of the pathogen Aphanomyces astaci in freshwater crayfish populations in Croatia.
abstract: The Oomycete Aphanomyces astaci is an obligate crayfish parasite that co-evolved with American crayfish species, and they therefore generally live in a balanced relationship. On the contrary, European native crayfish are highly susceptible to A. astaci, and infestation with it causes development of the lethal disease termed crayfish plague. Until now, 5 A. astaci strains have been described from the freshwater crayfish present in Europe. In this study we aimed to investigate the occurrence of the pathogen A. astaci in Croatian native and non-native crayfish populations, as well as to genotype established strains using microsatellite markers and obtain information on the pathogen's epidemiology. Our results showed that the pathogen is widespread in both native and non-native crayfish populations. Agent level, when positive, in non-native crayfish was generally low; in native species it was higher. Genotyping from microsatellites proved the presence of the B (Ps) strain in non-native species (Pacifastacus leniusculus), while the A (As) strain was detected from viable native species (Astacus astacus and Austropotamobius torrentium) that are distributed in areas lacking non-native crayfish. The genotype from A. torrentium differed from a typical A (As) by 1 allele. Strain B (Ps) was identified in native Astacus leptodactylus from the population that co-occurs with P. leniuscuslus. Interestingly, in 1 A. leptodactylus population both A (As) and B (Ps) strains were present.
authors: University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb, Croatia.
authors: Ivana
authors: I
authors: Maguire
authors: Mišel
authors: M
authors: Jelić
authors: Goran
authors: G
authors: Klobučar
authors: Mylène
authors: M
authors: Delpy
authors: Carine
authors: C
authors: Delaunay
authors: Frederic
authors: F
authors: Grandjean
mesh_terms: D000818:Animals; D044744:Aphanomyces / Q000502:physiology*; D003400:Astacoidea / Q000382:microbiology*; D017523:Croatia; D054884:Host-Pathogen Interactions; D060888:Real-Time Polymerase Chain Reaction