【摘要】 目的　探讨乙型肝炎( 乙肝)疫苗免疫失败与S基因变异的关系。方法　106 名乙肝疫苗免疫失败儿童血清为研究标本,从中提取DNA,经PCR 扩增乙肝病毒(HBV)S区基因片段、Southernblot 转移至尼龙膜,与S区标准序列探针杂交,选择PCR阳性与寡核苷酸探针不杂交的样本作序列分析。结果　免疫失败儿童中HBVDNA 阳性率为93-4% (99/106) ,99 份样本中有30 份与探针不杂交,占30-3% 。选择11 份作序列分析,10 份存在核苷酸变异伴氨基酸改变,分别位于氨基酸残基113(S→T,T→P)、126(I→T) 、127(P→T)、131(N→T)、143(S→T) 、161(Y→F)和175(L→F)。同时对一对母婴测序结果显示其序列完全一致,均存在131 和161 位氨基酸被取代。结论　该组免疫失败儿童中28-3% 存在S区基因变异。变异株可经母婴传播更多还原

【Abstract】 Objective To assess the correlation between the infants with surface gene mutant of hepatitis B virus (HBV) infection and failure in HB vaccination Methods Sera from 106 infants who were born to HBV carrier mothers and had failure of HB vaccination were detected for HBV mutant by means of PCR, Southern blot, oligonucleotide hybridization and direct sequencing Results Of the 106 cases, 99 (93 4%) were HBV DNA positive, 30 3% (30/99) of the samples failed to hybridize with any of the four probes DNA sequencing confirmed 10 out of 11 samples had S gene mutation with amino acid (aa) change The identified mutants include substitutions at nuclotide (nt) 546 T→A (aa131 N→T), nt531 T→C (aa126 I→T), nt491 A→C (aa113 T→P), nt491 T→A (aa113 S→T), nt533 C→A (aa127 P→T), nt581 T→A (aa143 S→T), nt 636 A→T (aa 161 Y→F) and nt 679 A→C (aa 175 L→F), respectively The sequence in one pair of mother and her infant showed completely the same with mutation at aa131 and aa161 Conclusion The prevalence of HBV S gene mutants in the children who failed in HB vaccination was about 28 3% The HBV mutants can be transmitted from mother to her infant更多还原