New CMS model presented at TriNation
VESO Vikan offers a new challenge model with CMS that was presented at the TriNation meeting in Bergen. Makoto Inami presented our new CMS challenge model during the CMS Workshop at the PD TriNation meeting in Bergen. The work has been carried out in collaboration with Espen Rimstad/ NMBU. The challenge model will provide new possibilities to understand the nature of the disease and the virus without interfering with other pathogens. The model will also be an essential tool to validate the efficacy of prophylactic treatments such as vaccines, health feeds and breeding programs.
Piscine myocarditis virus (PMCV) is the causative agent of cardiomyopathy syndrome (CMS). We have developed an experimental challenge model for infection with PMCV where the infected fish show histopathological changes consistent with CMS. Cultivation of PMCV in cell line systems has so far not been successful. Experimental transmission of CMS was therefore demonstrated using tissue homogenate from CMS-diagnosed fish. The challenge material originated from a highly virulent field outbreak of CMS, and was confirmed negative for other pathogens, including PRV, by in vivo cultivation and qPCR. Atlantic salmon smolts were challenged through an intraperitoneal or intramuscular injection, or by cohabitation with i.p. injected shedder fish. The diagnosis was based on histopathology as well as quantification of virus by qPCR. There was a strong correlation between Ct-values and degree of histopathological changes. No mortality was observed throughout this project.