Preliminary characterization of Tasmanian aquareovirus (TSRV) isolates.

In an attempt to determine whether or not genetic variants of the Tasmanian strain of Atlantic salmon aquareovirus (TSRV) exist, 14 isolates of TSRV, originating from various locations in Tasmania, covering a 20-year period (1990-2010), obtained from various host species and tissues, and isolated on different cell lines, were selected for this study. Two categories, termed "typical" and "atypical", of variants of TSRV were identified based on preliminary genotypic and phenotypic characterization carried out on these 14 different isolates. In addition, electron microscopic examination indicated the existence of at least three variants based on viral particle size. Finally, this study demonstrated the existence of at least one new variant of TSRV isolates, other than the more commonly isolated typical TSRV isolates, in farmed Tasmanian Atlantic salmon.