Base on the reactivity pattern of the Chinese isolates and reference strains with monoclonal antibodies of N protein(ISU15A-E),PRRSV isolates,Chinese isolates belong to group I according the category rule of American type.

• 根据N蛋白的单克隆抗体(ISU15A_E)与国内分离毒株的反应谱；按照美国L.；Yang等[3]分类方法；本试验中的国内分离毒株均属于I组。