Culture and growth characteristics of three street rabies virus strains isolated in China in cells and suckling mouse brain

Objective To compare the growth characteristics of three street rabies virus strains(SXYQ,YN01 and GDMMD57)isolated in China in cells and suckling mouse brain,and lay a foundation of the establishment of rabies virus infection model. Methods The three strains were subcultured in suckling mouse brain and in N2a cells respectively,of which the various passages were determined for infectious titers,and calculated for TCID50. Results The titers of SXYQ, YN01 and GDMMD57 strains subcultured in suckling mouse brain showed increasing tendencies with the increasing passage within passage 10,and were stable as 105. 85,105. 63 and 105. 97 TCID50/ g respectively after passage 8,which showed significant difference. However,the adaptabilities of SYXYQ,YN01,GDMMD57 strains in N2a cells increased with the increasing passage,while the titers showed increasing tendencies and were stable after passage 15,which showed significant difference. The titer of SXYQ strain of passage 20 reached a peak value of 106. 80TCID50/ ml 2. 5 d, while those of YN01 and GDMMD57(both 107. 30 TCID50/ ml) strains 3 d after infection. Conclusion All the three rabies virus strains reached high titers after subculture in both suckling mouse brain and cells,which might be used for the establishment of rabies virus infection model and development of novel rabies vaccines.