我国甲型肝炎病毒BJ73株全基因组测定与分析

Analysis of full-length hepatitis A virus genome isolated from a patient with acute hepatitis A inBeijing

目的从北京地区一例急性期甲肝患者血清中提取甲肝病毒核酸，获得一株甲肝病毒（HAV）全基因组序列，进行相关分析。方法分8段设计16对重叠基因片段引物，经提取病毒RNA、反转录、巢式PCR扩增及产物直接测序获得序列。结果获得的BJ73全基因组核苷酸全长7477bp，编码含2227个氨基酸的多聚蛋白；同源比对发现BJ73核苷酸和氨基酸序列均与LU38同源性最高，分别为99．1％和99．7％；VP3-VPI区域内已发表的抗原中和位点处未发现氨基酸变异；分别基于全基因序列和不同区段序列构建系统进化树，均表明BJ73病毒株属于IA亚型；选择压力分析表明全编码区处于负向选择。结论本实验得到的相关数据为我国甲肝病毒基因型分布、病毒进化等研究提供了依据和实验基础。

Objective To identify the complete nucleotide sequence of hepatitis A virus （HAV） extracted from serum of an acute hepatitis A patient in 2007 （ BJ73 ） in Beijing. Methods The full genomie sequence was sequenced and subjected to the phylogenetic analysis using Bioedit 7.0, MEGA5 and HyPhy. Results The genome of BJ73 consisted of 7477 nucleotides, encoding a polyprotein of 2227 amino acids. Sequence comparison showed that BJ73 shared the highest identities of 99. 1% for nucleotide and 99.7% for amino acid with LU38. Amino acid change was not observed in reference to published neutralizing antigenic sites in VP3-VP1 regions. Phylogenetic analysis included the BJ73 sequence in subgenotype IA, either considering different fragments or the full length nucleotide sequence; negative selection was found in coding regions. Conclusion This article provides new data on the distribution of virus evolution of HAV isolated from China. genotype and virus evolution of HAV isolated from China.