Occurrence of the microsporidian parasite Nucleospora salmonis in four species of salmonids from the Massif Central of France

• Main Authors: El Alaoui, Hicham, Grésoviac, Stéphane J, Vivarès, Christian
• Other Authors: Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: MESH: Animals; MESH: Base Sequence; MESH: Salmonidae; MESH: Sequence Alignment; MESH: DNA; Protozoan; MESH: Fish Diseases; MESH: France; MESH: Microsporidia; MESH: Microsporidiosis; MESH: Phylogeny; MESH: Polymerase Chain Reaction; MESH: RNA; Ribosomal; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; Atlantic salmon; Salmo salar; Salvelinus alpinus
• Online Access: https://hal.archives-ouvertes.fr/hal-00529770

International audience Nucleospora salmonis (Hedrick, Groff et Baxa, 1991), an intranuclear microsporidian parasite of marine and freshwater fish, causes diseases mainly in salmonid species. Losses have been reported in stocks of salmonid fish reared in the region of Auvergne (France). The cause of chronic mortalities in the local host species raised in aquaculture and destined for supplementation of the river system Loire-Allier was examined. The presence of N. salmonis was confirmed by PCR and histology in Salmo salar L. previously and in newly investigated salmonid species, Salmo salar, Salmo trutta fario L., Thymallus thymallus (L.) and Salvelinus alpinus (L.), present in European streams. The infection by N. salmonis was consistent in all cases with characteristic symptoms of the disease in deceased or moribund fish. The small subunit ribosomal DNA from N. salmonis was partially sequenced and compared to previously characterised N. salmonis isolates. As a result, a genotype, or clonal entity, was attributed to N. salmonis among Atlantic salmon found along the Northern Atlantic coastal lines and other salmonid species co-inhabiting or co-cultivated in the Auvergne region.