广西狂犬病病毒M基因序列分析

Sequence analyses of the M gene of rabies viruses in Guangxi province

目的探讨广西13株狂犬病病毒M基因遗传变异特征及其与狂犬病在广西流行的关系。方法用直接免疫荧光法(DFA)检测2006～2008年广西地区收集到的3 961份犬脑组织标本,将检测结果为阳性的脑组织标本进行RT-PCR扩增,双向测序M基因核苷酸序列,进行生物信息学分析。结果 DFA法检测阳性率为8.84%(350/3 961),RT-PCR法检测阳性率为14.57%(51/350);获得相应区段的狂犬病病毒核苷酸序列13份;MP基因同源性分析表示,13株病毒核苷酸序列与氨基酸序列同源性范围为85.4%～100%和91.1%～99.5%,M基因氨基酸序列同源性普遍高于相应区段的核苷酸序列。种系发生分析显示,13株病毒标本均属于基因Ⅰ型,除GX16毒株与国际上野生动物病毒基因Ⅰ型分离株进化关系较近外,其他广西分离株与CTN疫苗株及宁夏街毒株进化关系较近。结论 13株狂犬病病毒株均属于基因Ⅰ型狂犬病毒,但其在某些功能位点发生了变异。

Objective To analyze the genetic characteristics of 13 rabies isolates from Guangxi Province,and understand the relationship between these rabies isolates and current rabies epidemics in this province.Methods 3 961 dogs’ brain specimens were collected in 2006~2008 and detected by both direct immunofluorescence assay（DFA）and RT-PCR.Results 350 of 3 961 brain specimens were positive by DFA（positive rate of 8.84%）,51 of these positive samples were positive by RT-PCR（positive rate of 14.57%）,and 13 nucleotide fragments from corresponding region of viral nucleic acid were obtained..Phylogenetic analysis indicated that the virus strains shared the higher degree of homology,with a nucleotide identity of 85.4%~100% and an amino acid identity for M gene of 91,1%~99,5%.The virus strain GX16 was more closely related to the strain isolated from the wild animals in the world,and the other virus strains were more closely related to the vaccine strain CTN and Ningxia strains.Conclusion Compared with the classic rabies virus strains 13 rabies virus strains detected in Guangxi belong to genotype 1,but the M gene occurs some mutations in nucleotide sequence.