ISOLATION OF A CYTOPATHOGENIC VIRUS FROM A CASE OF PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME (PRRS) AND ITS CHARACTERIZATION AS PARAINFLUENZA VIRUS TYPE-2

From a lung of a fetus of a breeding sow showing PRRS-like symptoms a viral agent could be isolated. It was characterized as an enveloped, h emagglutinating RNA virus. Ultrastructural examination of purified vir us revealed paramyxovirus-like pleomorphic virions of approx. 200 nm i n diameter. The helical nucleocapsids were about 18 nm in diameter. Th e virus was found to be antigenically related to simian virus 5 (SV5) a prototype strain of parainfluenza virus type 2, but not to bovine re spiratory syncytial virus, parainfluenza virus type 1, parainfluenza v irus type 3, and Newcastle disease virus as determined by western blot analysis.