[Effect of Actinomyces rimosus ribonuclease on the reproduction of viruses].

Antiviral activity of RNA-ase isolated from the fermentation broth of Actinomyces rimosus was studied. The effect of the enzyme on multiplication of the viruses of vesicular stomatitis, Newcastle and cariolovaccine diseases was investigated. It was found that the enzyme was capable of suppressing reproduction of the vesicular stomatitis virus (VSV) in the culture of chick fibroblast cells. The suppression level directly depended on the enzyme concentration and decreased with an increase in the infection multiplicity. The enzyme had no effect on multiplication of other viruses tested. RNA-ase decreased the infectious properties of the freshly isolated virus-containing material in concentrations showing the antiviral effect. Preliminary incubation of the cells with the enzyme resulted in suppression of the plaque formation by VSV. The RNA synthesis in such cultures treated with RNA-ase was somewhat lower. It was shown that the antiviral effect of RNA=ase was connected with its enzymic activity. RNA-ase has no antiviral effect in the experiments with mice infected with VSV.