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SUMMARYThe physicochernical and serological properties of a virus isolated from the bivalve mollusc, Tellina tenuis, have been examined. The virus has a diam. of 59 nrn, sediments at 43oS in sucrose gradients and bands at a density of I-32 g/ml in CsC1. The virus contains RNA with a tool. wt. about 2.8 × IO 6 as estimated by polyacrylamide gel electrophoresis but in sucrose gradients the RNA sediments at I4S. The virus RNA is resistant to ribonuclease under conditions in which ribosomal RNA and the single stranded Mengo virus RNA are completely hydrolysed. Two major polypeptides, mol. wt. 67 and 40 × Io z, and one minor polypeptide, mol. wt. I I0 × 10 8, are present in the virus particle. These properties are similar to those found for different serotypes of infectious pancreatic necrosis (IPN) virus. Although there was only a very low level of cross-neutralization between Tellina virus and IPN virus, there was some cross-reaction in immune electron microscopy tests and in irnmunofluorescence tests with infected tissue culture cells. This cross reaction, together with the close similarity in morphology and physicochernical properties, suggests that Tellina virus and IPN virus belong to the same virus group.

SUMMARYThe relatedness of swine vesicular disease virus (SVDV) and Coxsackie B5 virus has been studied by virus neutralization and immunodiffusion tests and by hybridization of the virus RNAs. Clearly defined differences between the two viruses were found by the three methods. Isolates of SVDV from several countries were very closely related but could be differentiated. Recent isolates of Coxsackie B5 virus also appeared to be similar but clear differences could be detected between these and the prototype (Faulkner) strain of the virus. The SVDV isolates were more closely related to the Faulkner strain than to the recent isolates of Coxsackie B5 virus. Perhaps of more importance, the Faulkner strain was more closely related to SVDV than it was to the recent Coxsackie B5 isolates. The significance of these observations in relation to the recent emergence of swine vesicular disease is discussed.

Two bullet-shaped viruses, isolated from eels, have been characterized physico-chemically, and their serological relationship to the other fish rhabdoviruses has been determined. Preparations of each virus contain truncated as well as bullet-shaped particles and the RNAs from these sediment at 18S and 4IS, respectively. As determined by PAGE, the virion polypeptide patterns for both viruses were indistinguishable, but were found to differ from those of the other fish rhabdoviruses. Using vesicular stomatitis virus polypeptides as internal markers, the molecular weights of the eel virus polypeptides were calculated to be > 150,000, 64,000, 49,000, 47,000 and 26,000. The two viruses are closely related to each other antigenically, but show no relationship to the other fish rhabdoviruses in neutralization tests.