Study on the attenuated effect about A2 strain of HRSV in cell culture at low temperature.

[Objective] To analysis the change of human respiratory syncytial virus(HRSV) after generation at low tem-perature in human diploid cell KMB17.[Methods] The HRSV A2 strains were cultured and passaged in the human diploid cell KMB17 at 32℃ lower temperature, the different generation virus inoculated to the nose of guinea pigs, and then respectively from lung tissue for biopsy pathology on the 7th days and 14th days, to separate serum for antibody test;To study the growth curve and temperature sensitivity characteristics of the virus.[Results] The weight of guinea pigs in the group of inoculated primal virus was lighter than the control group on the 14th day.The weight of 6th and 11th group were similar with the-control-group.Interstitial pneumonia emerged in the three groups.The step growth curve did not significantly change of the 6th and 11th group virus after passaged at 32℃ lower temperature in cell, and the growth peak was 9-12 days after inoculation.[Conclu-sion] HRSV inoculating to the nose of guinea-pig can cause lung infection, guinea-pig can be considered as the animal model of toxicity assessment.The A2 strain was not attenuated on cold-passaged 11th in KMB17 cell at 32℃ lower temperature, still induces interstitial pneumonia.