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: As there was a trend that passage reduces the virulence of the tested strains (5337 and 2736), we were interested in finding out whether the passaged strains (15P) when re-isolated from dead fish would remain with reduced virulence or yield a successful infection. For strain 5337, all three passages (5337AP, 533715P and 5337AP15P) were significantly different from the control at 14 days post-infection. 533715P was also significantly different from the other two. However, there was no difference between 5337AP and 5337AP15P (Fig. 4).