Effect of actinomycin D on the cytopathology and replication of porcine enteroviruses

Actinomycin D inhibited the cytopathic effects (CPE) of type II strains of porcine enteroviruses in PK-15 cells but had no consistent effect on viral replication. The maximum inhibition of CPE was observed when the antibiotic was present during the early stages of infection. No inhibition of the CPE induced by type I strains was observed. A correlation was found between the activation of lysosomal acid phosphatase and morphological changes in the infected cells and the release of progeny virus. Diffuse enzymatic activity was more pronounced in cells infected with type II strains. The activation of lysosomal acid phosphatase by type II strains was inhibited by actinomycin D, while that of type I strains remained unaffected.