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: The 2736 strain gave low CPI for all passages tested (Fig. 2), with a CPI of 23.3 by day 14 post-challenge (Fig. 2; Table 2). The first infected fish were observed by day 5 post-infection for the 2736AP-challenged fish (Fig. 2). Passage reduced the virulence of strain 2736, with a CPI at 14 days of 6.7 for 27365P and 3.3 for 273615P. There were significant differences in CPI between AP and 5P/15P challenges (Fig. 2).