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为了解2008~2009年珠海市H3N2亚型流感病毒HA1基因变异情况,选择珠海市2008~2009年期间不同时间点的经狗肾传代细胞(MDCK)培养分离的H3N2亚型流感毒株20株,提取病毒RNA,通过RT-PCR扩增HA1基因片段,将产物纯化并测序,推导氨基酸序列,进行基因进化特性分析。与同时期的疫苗株比较,2008年珠海市流行的H3N2亚型流感毒株HA1区抗原决定簇的氨基酸位点变异数少于4个;2009年珠海市流行的H3N2亚型流感毒株除09-0056外,HA1区存在5个位于抗原决定簇内的变异氨基酸位点。2008年H3N2亚型流感毒株的HA1区的糖基化位点与疫苗株一致;2009年H3N2亚型流感毒株HA1区丢失第144位糖基化位点。2008~2009年H3N2亚型流感毒株RBS氨基酸序列未见明显变异。与2008年H3N2亚型流感毒株比较,2009年H3N2亚型流感毒株HA1区抗原决定簇内存在多个位点的氨基酸替换。这些说明2008年珠海市流行的H3N2亚型流感病毒不是新变种;2009年流行的H3N2亚型流感病毒为新的变异株,这可能是H3N2亚型流感病毒在2009年6-9月为珠海地区季节性流感流行优势株的原因。
In order to understand the variation of HA1 gene in Zhuhai H3N2 influenza virus from 2008 to 2009, 20 strains of H3N2 subtype influenza virus isolated from Zhuhai city at different time points from 2008 to 2009 were isolated from MDCK. The viral RNA was extracted, the HA1 gene fragment was amplified by RT-PCR, the product was purified and sequenced, the amino acid sequence was deduced, and the gene evolution characteristics were analyzed. Compared with the same vaccine strain in 2008, the prevalence of H3N2 subtype influenza strains in Zhuhai in 2008 was less than 4 in HA1 epitopes. In 2009, the prevalence of H3N2 subtype influenza strains in Zhuhai except 09 -0056, there are five mutated amino acid sites in the HA1 region located within the epitope. In 2008, the glycosylation site of HA1 region of H3N2 subtype influenza virus strains was consistent with the vaccine strain; in 2009, the HA1 region of H3N2 influenza virus lost the 144th glycosylation site. The amino acid sequence of RBS of H3N2 subtype influenza virus from 2008 to 2009 showed no obvious variation. Compared with H3N2 subtype influenza virus strains in 2008, amino acid substitutions at multiple sites existed in the antigenic determinant of HA1 region of 2009 H3N2 influenza virus strains. These show that Zhuhai epidemic H3N2 subtype influenza virus in 2008 is not a new variant; 2009 H3N2 subtype influenza virus is a new variant of the popular strain, which may be H3N2 subtype influenza virus in June-September 2009 for the Zhuhai area The reason for the seasonal flu pandemic strain.