Immunofluorescent Study of the Replication of Infectious Pancreatic Necrosis Virus in Trout and Atlantic Salmon Cell Cultures

• Published in: Infection and Immunity
• Main Authors: Piper, Donald, Nicholson, Bruce L., Dunn, James
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Society for Microbiology 1973
• Subjects: Infectious Diseases; Immunology; Microbiology; Parasitology; Atlantic salmon
• Online Access: http://dx.doi.org/10.1128/iai.8.2.249-254.1973; https://journals.asm.org/doi/pdf/10.1128/iai.8.2.249-254.1973

Cell cultures of trout gonad tissue (RTG-2) and Atlantic salmon heart, kidney, liver, and spleen tissue were inoculated with 50 50% tissue culture infective doses (TCID 50 ) of infectious pancreatic necrosis (IPN) virus per cell, and the titer of cell-associated and released virus was determined from 2 to 16 h postinoculation (PI). Cover slips were collected over the same period and stained for IPN viral antigen by the direct immunofluorescent (FA) technique. Viral replication was detected after a latent period of approximately 2 to 4 h and reached a peak titer of 10 8.2 to 10 8.4 TCID 50 per ml at 8 to 10 h PI. The release of virus was more rapid in Atlantic salmon cells than in RTG-2 cells. Viral antigen was first detected by FA from 3 to 4 h PI. Approximately 75 to 80% of the cells contained antigen in the cytoplasm 9 to 11 h PI. The direct FA technique was found to be a sensitive method for detecting IPN virus in infected cells. Three strains of IPN virus were tested for serological cross reactions by FA and virus neutralization tests.