The mode of action of an antiviral substance from Penicillium cyaneo-fulvum

Abstract

An antiviral substance elaborated in Czapek-Dox broth by a strain of Penicillium cyaneo-fulvum isolated in this laboratory, and active against influenza A virus (PR8), influenza B virus (Lee), and Newcastle disease virus (B₁) in modified Maitland tissue cultures has been shown to act at an intracellular site in the viral replicative cycle. The substance neither blocks virus adsorption nor impedes the release of newly formed virus particles. It is not viricidal, does not interfere with the action of ths viral neuraminidase on red blood cells, and does not possess any haemagglutination or haemagglutination–inhibition activity. A comparison with other reported antiviral agents shows that the antiviral substance is different from those previously studied.