Show simple item record

dc.contributor.authorNylund, Are
dc.contributor.authorHansen, Haakon
dc.contributor.authorBrevik, Øyvind Jakobsen
dc.contributor.authorHustoft, Håvard
dc.contributor.authorMarkussen, Turhan
dc.contributor.authorPlarre, Heidrun
dc.contributor.authorKarlsbakk, Egil
dc.PublishedNylund A, Hansen H, Brevik ØJ, Hustoft H, Markussen T, Plarre H, Karlsbakk E. Infection dynamics and tissue tropism of Parvicapsula pseudobranchicola (Myxozoa: Myxosporea) in farmed Atlantic salmon (Salmo salar). Parasites & Vectors. 2018;11:17:1-13eng
dc.description.abstractBackground The myxosporean parasite Parvicapsula pseudobranchicola commonly infects farmed Atlantic salmon in northern Norway. Heavy infections are associated with pseudobranch lesions, runting and mortality in the salmon populations. The life-cycle of the parasite is unknown, preventing controlled challenge experiments. The infection dynamics, duration of sporogony, tissue tropism and ability to develop immunity to the parasite in farmed Atlantic salmon is poorly known. We conducted a field experiment, aiming at examining these aspects. Methods Infections in a group of Atlantic salmon were followed from before sea-transfer to the end of the production (604 days). Samples from a range of tissues/sites were analysed using real-time RT-PCR and histology, including in situ hybridization. Results All salmon in the studied population rapidly became infected with P. pseudobranchicola after sea-transfer medio August. Parasite densities in the pseudobranchs peaked in winter (November-January), and decreased markedly to March. Densities thereafter decreased further. Parasite densities in other tissues were low. Parasite stages were initially found to be intravascular in the pseudobranch, but occurred extravascular in the pseudobranch tissue at 3 months post-sea-transfer. Mature spores appeared in the pseudobranchs in the period with high parasite densities in the winter (late November-January), and were released (i.e. disappeared from the fish) in the period January-March. Clinical signs of parvicapsulosis (December-early February) were associated with high parasite densities and inflammation in the pseudobranchs. No evidence for reinfection was seen the second autumn in sea. Conclusions The main site of the parasite in Atlantic salmon is the pseudobranchs. Blood stages occur, but parasite proliferation is primarily associated with extravascular stages in the pseudobranchs. Disease and mortality (parvicapsulosis) coincide with the completion of sporogony. Atlantic salmon appears to develop immunity to P. pseudobranchicola. Further studies should focus on the unknown life-cycle of the parasite, and the pathophysiological effects of the pseudobranch infection that also could affect the eyes and vision.en_US
dc.publisherSpringer Natureen_US
dc.rightsAttribution CC BYeng
dc.subjectSalmo Salareng
dc.subjectin situ hybridizationeng
dc.subjectReal-time RT-PCReng
dc.titleInfection dynamics and tissue tropism of Parvicapsula pseudobranchicola (Myxozoa: Myxosporea) in farmed Atlantic salmon (Salmo salar)en_US
dc.typePeer reviewed
dc.typeJournal article
dc.rights.holderCopyright The Author(s) 2018en_US
dc.source.journalParasites & Vectors

Files in this item


This item appears in the following Collection(s)

Show simple item record

Attribution CC BY
Except where otherwise noted, this item's license is described as Attribution CC BY