[Study of the multiplication in cell cultures of two strains of para-influenza virus type 3. III. Multiplication in BHK 21 cells].

: Study was conducted on the multiplication of two strains (C243 and D) of parainfluenza virus type 3 in BHK 21 cells. Multiplication curve of the virus was established and immunohistochemical aspects of the process were investigated. Chronological study of successive steps of the formation and development of viral components allowed to see that the virus multiplication rate is low in this cell system. The parainfluenza antigen became detectable by immunofluorescence in the infected cell perinuclear region after a relatively long eclipse period (18 h) and synthetized virus has few RNA and induced no inclusion information in the cytoplasm or the nucleus. However, an important nuclear participation was noted: 72 h after inoculation, nuclear fluorescence was observed, as well as a nuclear DNA rising and frequent aberrant mitoses. Comparison between the two investigated strains led to the observation that the autochthonous D strain induced more frequent aberrant mitoses and more important cell destruction than the C243 one. Differences were also noted as regards the infecting and hemagglutinating titers.