Salmonid viruses: Double infection of RTG-2 cells with Egtved and infectious pancreatic necrosis viruses

Egtved and infectious pancreatic necrosis (IPN) viruses were applied at high multiplicity alone and in combination to RTG-2 cells in liquid medium. Procedures were used which selectively suppressed one or the other virus, and the yields were determined after 64 hours at 15°C. The viruses showed an increase of 280 to 450 times the immediate post-adsorption level. Plaques of IPN and Egtved viruses showed some differences which can be helpful in distinguishing between the two agents. Detailed methods and results are given.