广西狂犬病病毒与狂犬病疫苗株N基因序列分析

目的了解广西狂犬病病毒（RABV）街毒株与疫苗株N基因序列的差异，为疫苗使用提供理论依据。方法采用直接免疫荧光法（DFA）和巢式RT—PCR法检测，测定病毒N基因序列全长，同时根据N基因序列同源性及系统进化树比较，分析广西近年流行的RABV与国内外10株疫苗代表株N基因序列之间的差异。结果DFA法阳性率为8．84％（350／3961），RT—PCR法检测阳性率1．29％（51／3961），获得N基因全序15份；15份N基因核苷酸与氨基酸序列同源性为89．40％。100％和98．40％~99．80％；广西15份（RABV）与国内外10株疫苗代表株N基因核苷酸和氨基酸序列同源性分别为85．70％～99．70％和94．90％～99．80％，与中国CTN疫苗株N基因的核苷酸和氨基酸同源性最高，分别为89．60％，99．70％和98．40％。99．80％。N基因系统发生树分为两大分支，15份（RABV）与中国人用CTN株构成第一分支，其余的疫苗毒株构成第二分支。结论广西犬间流行的RABV与中国人用CTN疫苗株N基因序列同源性最高、亲缘关系最近，在广西地区使用CTN疫苗株效果可能较好。

Genetic sequence analysis of N gene from 15 rabies virus strains in Guangxi province and the vaccine strains

Objective To study the N gene sequence differences and evolutionary correlatins between the rabivirus strains collected in Guangxi and vaccine strains used in rabivires vaccine, and solve the problem of choosing the right human rabies vaccine genetically. Methods N gene＇ s whole genome sequences of the local strains in Guangxi and vaccines strains were obtained by using DFA RT-PCR methods. Constructed Phylogenetic tree of all strains was compared and their homology was also analysed. Results Fifteen N-gene sequences were obtained and the results showed a positive rate of 8.84%（350 out of 3 961）by DFA method and 1.29% （51 out of 3 961） by RT-PCR method. All 15 N-gene sequences enjoyed a nucleotide sequence homologyof 89.40 % ~ 100% and an amino acid sequence homology of 98.40%-99.80%. Their homological rates were 85.70% ~99.70% and 94.90%-99.80% when compared with 10 vaccine strains from home and abroad. Among all strains, the homology of Chinese CTN vaccine strain was highest ,with 89.60 %-99.70 % in nucleotide sequences and 98.40 %-99.80 % in amino acid sequence. According to phylogeny all strains were divided into two groups, 15 local virus strains and the Chinese CTN vaccine strain belonged to the same group , and the rest vaccine strains belonged to another group. Conclusion The studied rabies viruse strains in Guangxi province share the highest genetic homology and the closest N-genetic relationship with the Chinese human CTN vaccine strain, which suggests a better effectiveness may be obtained by using CTN human rabies vaccine in Guangxi province.