学龄前儿童乙型肝炎病毒株氨基酸变异研究

Amino acid variation of HBV strain among preschool children

目的了解学龄前儿童（2~6岁）隐匿性乙型肝炎病毒感染（OBI）后HBV S基因氨基酸的变异情况,为防控OBI的发生发展提供参考。方法采用整群抽样方法选择乌鲁木齐4所幼儿园,对在园的学龄前儿童采用ELISA进行HBs Ag,anti-HBs,HBe Ag,anti-HBe和anti-HBc 5项检测,对259例HBs Ag阴性的血清用Promega公司生产的试剂盒进行HBV-DNA产物提取,运用PCR方法扩增HBV-DNA S基因片段,对扩增阳性的序列进行测定;采用分子遗传学软件MEGA5.0对测得的序列进行具体氨基酸分析。结果 259份学龄前儿童血样共发现21份HBV DNA阳性标本,均测序成功。其中1例由于存在氨基酸的插入,没有检出具体的基因型。其余20例样本均表现为C基因型,血清型均为adrq＋亚型。S基因序列翻译成氨基酸后分别发生I110L,S123T,T124S,T126I,T131N,F134Y和P142H突变。结论 HBs Ag阴性学生血液中存在一定数量的HBV隐匿性感染,S基因存在氨基酸突变,需重视隐匿性的HBV感染以及其发生和发展。

Objective To investigate the variation of S gene amino acids among e preschool children infecting occult hepatitis B virus infection. Methods Four kindergardens were chosen by cluster sampling method. ELISA was used to detect HBs Ag,HBs Ab, HBe Ag, HBe Ab and HBc Ab. HBV-DNA product was extracted with Promega kit, 259 cases of HBs Ag negative serum,PCR amplification of HBV-DNA S gene fragment, on the discovery of the copies of the target band sequencing. Molecular genetic for amino acid sequence was analyzed by MEGA5.0 software. Results A total of 259 samples were successfully sequenced. One case due to the presence of amion acid insertion and led to a frame shift mutation, so did not detect the gene type. The other 20 samples were C genotype, serotype were adrq＋ sub-type. S gene sequence translated into amino acids respectively I110 L, S123 T, T124 S,T126I, T131 N, F134 Y and P142 H mutations. Conclusion The HBV infection has been observed among preschool children with negative HBs Ag, and there are S gene mutations in amino acid.