浙江省流行性感冒病毒分离株HA1基因分析
Analysis on characteristics of HA1 gene of Influenza virus strains isolated in Zhejiang province
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摘要:目的 研究浙江省近2年新分离的甲3型流行性感冒(流感)病毒株血凝素HA1基因特性, 以了解浙江省流感病毒变异情况和WHO推荐疫苗株对人体的保护情况。方法 采集浙江省近2年类流感病人的咽拭子和含漱液标本进行流感病毒的分离, 对分离到的甲3型流感病毒进行核酸的提取, 采用逆转录-聚合酶链反应(RT-PCR)扩增病毒基因后进行核苷酸序列测定, 用DNA MAN和BioEdit生物软件对测序结果进行分析处理, 并与WHO推荐疫苗株进行比对。结果 近2年新分离到的甲3型流感病毒株HA1区域的核苷酸序列长度均为987bp, 未发现核苷酸的丢失和插入, 相应的点突变率为0.8%~1.3%, 推导的氨基酸序列长度均为329个。2003年分离的毒株与同期WHO推荐使用的疫苗株A/Moscow/10/99比较, 核苷酸同源性只有95.6%~95.9%, 氨基酸总变异达20个, 发生在抗原决定簇A、B区的有6个位点。2004年分离的毒株与同期WHO推荐使用的疫苗株A/fujian/411/2002(A/Ku-mamoto/102/2002, A Wyoming/3/2003)比较, 核苷酸同源性达98.6%~99.1%, 仅发生3~6个氨基酸的变异。基因进化树上, 浙江省2003, 2004年新分离的毒株均属于同一类性状的毒株, 与2004年WHO推荐疫苗株接近, 已远离2003年推荐疫苗株。结论 浙江省甲3型流感病毒的抗原性已发生漂移, 与我省流感的流行密切相关。2003年WHO推荐使用的甲3型流感疫苗对我省甲3型流感的预防效果不够理想, 2004年推荐使用的疫苗对我省甲3型流感的预防效果较好。Abstract:Objective To study the characteristics of HA gene of the subtype A3 influenza viruses isolated in the influenza outbreaks in Zhejiang province in recent two years.To know the mutation of influenza viruses in Zhejiang Province and the protectire effect of the vaccine strain recomended by WHO.Methods Respiratory specimens were collected from the influenza like cases in 2003~2004 in Zhejiang province and the influenza virus were isolated from the specimens, A3 influenza viruses were extracted.Their HA1 genes were amplified by reverse transcription polymerase chain reaction(R T-PCR), The PCR products were sequenced, The data obtained were analysed with the software DNAMAN and Eio Edit.Results The nucleiotides of HA1 region in the strains all were 987bp long and the deduced amino acids were all 329, there were no deletion and insertion in the nucleiotides.Accordingly, the point mutation percent was 0.8% ~1.3%.The strain isolated in 2003 had only 95.6% ~95.9% identity in nucleiotide sequence compared with A/Moscow/10/99 vaccine strain recommended by WHO at that time, and besides, there were 20 amino acids which had changed and six variant amino acid were found locating in the antigenic determinant sites A and B.The strain isolated in 2004 had 98.6%~99.1% identity in nucleiotide sequence compared to A/Fujian/411/2002(A/Kumamoto/102/2002, A/Wyoming/3/2003)vaccine strain recommended by WHO at that time, only 3~6 amino acid had changed.In the phylogenic tree, the strains isolated in 2003 and 2004 belonged to the same type which were near to the vaccine strain recommended by WHO in 2004 and far away from the vaccine strain recommended by WHO in 2003.Conclusion The antigenic drift of influenza A3 of Zhejiang province had occurred which connected with the popularity of influenza in the province.The vaccine produced by the influenza A3 vaccine strain recommended by WHO in 2003 was of no protective effect to the influenza of the province, and the vaccine produced by the influenza A3 vaccine strain recommended by WHO in 2004 had good protective effect to the influenza in Zhejiang province.
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