2011年南昌市乙型流感病毒HA1基因特征分析

Genetic characteristics of haemagglutinin of influenza B virus in Nanchang,2011

目的了解南昌市2011年乙型流感病毒HA1基因的特征,探讨2011年流感监测季乙型流感病毒的分子流行病学特征。方法按照采样时间,选取南昌市2011年从犬肾传代细胞(MDCK)培养分离到的乙型流感毒株共25株,提取病毒核糖核酸(ribonucleic acid,RNA),反转录-聚合酶链反应(reverse transcription-polymerase chainreaction,RT-PCR)扩增HA1基因片段,产物纯化测序,进行基因进化特性分析。结果 2011年南昌市流行的乙型流感病毒优势株为Victoria系病毒(84%)。与北半球国际疫苗株B/Brisbane/60/2008相比,2011年南昌市流行的Victoria系乙型流感病毒HA1片段有8个氨基酸位点发生了变异,其中T197D氨基酸变异涉及抗原决定簇的B区。与北半球国际疫苗株B/Wisconsin/1/2010相比,Yamagata系流感病毒HA1片段有19个氨基酸位点发生了替换,其中R130K、T165N、Q195R、Q196T,氨基酸变异涉及A、C、D三个抗原决定簇。结论 2011年南昌市流行的乙型流感病毒优势株属Victoria系,分离到的Yamagata系毒株血凝素基因发生了明显变异,Victoria系毒株血凝素基因未发生明显的变异。

Objective To understand the haemagglutinin genetic characteristics and molecular epidemiological characteristics of influenza B virus in Nanchang,Jiangxi province,in 2011.Methods Totally 25 strains of influenza B virus isolated in Nanchang in 2011 were cultured in MDCK cell.Viral RNA were extracted and HA1 gene were amplified by using RT-PCR.The amplified products were purified and the nucleotide sequences were determined,the results were analyzed by Mega 4.1 software.Results It was found that Yamagata lineage and Victoria lineage virus strains co-circulated in Nanchang in 2011 and the Victoria lineage virus was predominant（84%）.Compared with the vaccine strain B/Brisbane/60/2008,there were 8 amino acids substitutions in HA1 fragment of Victoria lineage strains in 2011,in which there was 1 amino acid mutation relating to antigenic sites B.Compared with the vaccine strain B/Wisconsin/1/2010,there were 19 amino acids substitutions in HA1 fragment of Yamagata lineage strains,the mutations of R130K,T165N,Q195R,Q196T were related to antigenic sites A,C and D.Conclusion The circulated Victoria lineage virus was the predominant strain of influenza B virus in Nanchang in 2011,and there was no obvious variation of haemagglutnin in Victoria lineage strains,but in Yamagata lineage strains.