Plaque morphology of some South American strains of foot-and-mouth disease virus and the effects of polyionic compounds on plaque formation

Abstract

The plaque forming ability of attenuated and field strains of FMDV of types A and O Vallee and C Waldmann were compared in BHK cell cultures. It was found that the vaccine strains attenuated by chick embryo passage produced smaller plaques. Reactor viruses recovered from vaccinated animals generally produced larger plaques than the vaccine and field strains. Type O vaccine, reactor and field viruses produced plaques of less variation in size and morphology. Field viruses of types A and C produced non-clear plaques which are readily distinguishable from the corresponding vaccine and reactor viruses.