【摘要】 为明确扬州市乙型肝炎病毒基因型分布和S基因特征及突变,从乙型肝炎病毒核酸(HBV DNA)荧光PCR检测855例阳性样本中随机抽取24例,扩增HBV S基因并测序成功获得17个条带,采用Clustal W与HBV A～H基因型参考序列比对构建距离矩阵,用MegAlign比对突变位点,分析氨基酸替代对抗原性的影响,用Protean软件分析主蛋白二级结构。结果表明:17个条带分别位于基因进化树的B和C基因型分支上,其同源性为93.0%～100%。基因B型间同源性93.3%～100%,C型间同源性93.0%～99.8%,同基因型间的同源性最高,与基因A型的同源性最低41.2%。17例样本主蛋白有8例发生氨基酸突变,有11个突变位点,在α决定簇环1中有2个突变位点AAI(126)T和AAF(134)L,其他变异位点位于核膜中。变异表现为点突变,发生突变的氨基酸极性和主蛋白二级结构未改变。这一研究提示扬州市HBV流行以B和C基因型为主,同源性高,突变率较低,未发现突变优势株,病毒表面蛋白的主蛋白抗原性未改变。更多还原

【Abstract】 In order to clarify the genotype distribution of HBV in Yangzhou and the characteristics and mutation of S gene,analyze the effect of gene mutation on the immunogenicity of antigen epitope,and provide experimental basis for vaccine immunity,the following studies were conducted.Twenty-four cases were randomly selected from the 855 positive samples detected by HBV DNA fluorescence PCR.HBV S gene was amplified and 17 bands were successfully sequenced.Then the distance matrix was constructed by Clustal W comparison with A-H genotype reference sequences and the mutation sites were found by MegAlign comparison to analyze the impact of amino acid substitution on antigenicity.The results showed that the 17 bands were located in B and C genotype branches of the genetic evolution tree with 93.0%-100% homology.The homology between genotype B was 93.3%-100%,and that between genotype C was 93.0%-99.8%.The homology between the same genotypes was the highest,and the homology with genotype A was the lowest41.2%.The prevalence of HBV in Yangzhou were dominated by B and C types,with high homology and low mutation rate.No mutant dominant strains were found and the antigenicity of SHBs remained unchanged.The prevalence of HBV in Yangzhou were dominated by B and C genotype,with high homology and low mutation rate.No mutant dominant strains were found and the antigenicity of SHBs remained unchanged.更多还原