Biochemical and Biophysical Characterization of Calicivirus Isolates from Pinnipeds

Abstract

Two virus isolates from California sea lions and one from an Alaskan fur seal, classified as caliciviruses based on their relationship to vesicular exanthema of swine virus, were examined for biochemical and biophysical properties. They all had a buoyant density of 1.37 g/ml in CsCl; one showed some heterogeneity in CsCl. The sedimentation rate in 5–20% sucrose was 183S for all three. Crystals were obtained from one of the viral preparations. RNA, but no DNA, was present inall three. The molecular weight of the genome was probably 2.6 × 10⁶ daltons, and the particle mass probably 12 × 10⁶ daltons.

Biophysical Comparisons of Calicivirus Serotypes Isolated from Pinnipeds

“…ID. E, F, respectively) were identical to that of the previously established SMSV-1 at 183S [6], Isolated viral peaks were observed by sedimentation of infected tissue culture fluid into sucrose, but in CsCI gradients some preparations showed varying amounts of radioactively-labeled extraneous material. Therefore, with these preparations we employed a preliminary sucrose gradient puri fication prior to centrifugation in CsCI (for example, SMSV-4, fig.…”

Characterization of Two New Serotypes of San Miguel Sea Lion Virus

“…Such heterogeneity has not been observed with SMSV isolates, nor has it been reported by others [11], However, density ranges of 1.36 to 1.39 g/ml encompass the densities previously reported forSMSV and VESV [10,11,[16][17][18]. Isolate 205 appears slightly heavier than most reported members o f the Caliciviridae but is still distinct from other small RNA viruses which have densities of 1.34 g/ml for enteroviruses, 1.40 g/ml for rhinoviruses and 1.43 g/ml for foot and mouth disease virus [18].…”

“…Based on the physicochemical and morphologic characteristics, virus isolates 15FT and 205 fit the taxonomic classification of the Caliciviridae [14,15] and differ from a previously isolated calicivirus of pinnipeds only in their buoyant density [11]. Although the buoyant density of 15FT, SMSV-1 and 205 are quite distinct, similar differences have been reported between the serotypes of VESV.…”

Prevalence and distribution of serum neutralizing antibodies to San Miguel sea lion virus types 6 and 7 in selected populations of marine mammals

“…Evldence indicates that caliciviruses are actively circulating among a vallety of Pacific rim marine species, including pinnipeds, cetaceans, and fish , Smith 1981). These viruses are of considerable importance because they are morphologically and physicochemlcally indistinguishable from the exotic disease agent, vesicular exanthema of swine virus (VESV), and are capable of producing vesicular disease in experimentally exposed pigs (Bachrach & Hess 1973, Schaffer & Soergel 1973, Smith et al 1973, 1980b Inter-Research/Printed in F. R. Germany Breese & Dardiri 1977, Wilder et al 1977, Wilder & Dardin 1978. Such findings have served to support the hypothesis that the costly outbreaks of vesicular exanthema of swine (VES) that spread throughout California and eventually to the remainder of the United States between 1932 and 1956 originated from calicivirus reservoirs in the sea.…”