ATTENUATED STRAIN OF BOVINE RS VIRUS

摘要

PURPOSE:Bovine RS viruses separated from cattles naturally infected with bovine RS virus is used to effect attenuation by subculture to give a strain having immunogenecity against Rous Sacroma Viruses in the field without pathogenecity. CONSTITUTION:Bovine RS viruses are obtained by culturing them separated from nasal fluid from cattles which have shown symptoms of respiratory diseases in a vobine kidney tissue culture. The viruses are inoculated to the lung cell culture of hamsters to effect cultivation for 30min. Further subculture of the viruses is carried out with the cells to proliferate the viruses. The proliferated viruses are cultured with passage of generations to effect 3-time cloning to give the attenuated strain of vobine RS virus. Since the strain has no longer pathogenicity, it can safely prevent the cattles from being infected with respiratory diseases caused by RS virus in the fields.