In vitro passages impact on virulence of Saprolegnia parasitica to Atlantic salmon, Salmo salar L. parr.
Bottom Line: The effect of serial in vitro subculturing on three pathogenic strains of Saprolegnia parasitica was investigated.Two of the strains declined in virulence after 15 successive in vitro subcultures, whereas one did not.It reveals that some strains degenerate more rapidly than others when subjected to successive in vitro subculturing on glucose-yeast extract.
Affiliation: Norwegian Veterinary Institute, Oslo, Norway.Show MeSH
Related in: MedlinePlus
Mentions: Infection was confirmed by typical gross changes where signs varied from cotton-wool-like tufts on the fins, head, integument and gills (Fig. 7), to focal areas of haemorrhage, necrosis and ulceration. Clinical signs included lethargy and loss of equilibrium in cases where the fish was seen swimming in circles almost above the water surface.