Wang Zhao-guo, Yang Ting-ting, Chai Qing, Liu Xiao-lin, Yi Ying, Yang Yu, Yu Ping, Wang Zhi-yu
Department of Microorganism and Parasite Test, Qingdao Municipal Center for Disease Prevention and Control, Qingdao 266033, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2013 Jan;47(1):35-9.
To investigate the evolution features of whole-genome of influenza virus H3N2 prevalent in Qingdao from year 2007 to 2011.
The RNA of 58 strains of influenza virus H3N2 prevalent in Qingdao between 2007 and 2011 was extracted and all segments amplified by RT-PCR. The sequence was then detected and assembled by software Sequencer. A total of 589 strains of influenza virus H3N2 with more than 300 amino acid recorded by GenBank were selected. The phylogeny and molecular features of all gene segments were analyzed by software Mega 5.0, referred by the heavy chain of hemagglutinin (HA1).
Hemagglutinin (HA) genes of influenza virus H3N2 prevalent in Qingdao between year 2007 and 2011 formed a single trunk of phylogenetic tree. Every prevalent strain originated in last season. The analysis of the evolution of whole genome found that reassortment virus strains were prevalent between year 2009 and 2010, but between 2010 and 2011 there were two series of prevalent strains, which showed complicated reassortment. Compared with the vaccine strains, the variant amino acids of protein of virus HA1 between year 2007 and 2011 were 8, 6, 6, 8 and 11, involving 13 antigenic sites. The sequence analysis of M2 protein showed that the isolated influenza virus H3N2 mutated in amino acid site 31, from serine to asparagine (S31N). HA1 gene of influenza virus H3N2 isolated in Qingdao between 2007 and 2011 shared the similar phylogenetic tree with the globally prevalent strain. The comparison of the sequence and the analysis of the antigenicity found co-infection between H3N2 and A/H1N1 in the strain A/Qingdao/F521/2011.
The evolution features of all segments of influenza virus H3N2 prevalent in Qingdao between year 2007 and 2011 were complicated.
研究2007年至2011年在青岛流行的H3N2流感病毒全基因组的进化特征。
提取2007年至2011年在青岛流行的58株H3N2流感病毒的RNA，通过RT-PCR扩增所有片段。然后用Sequencer软件进行序列检测和组装。从GenBank中选取589株记录了300多个氨基酸的H3N2流感病毒。用Mega 5.0软件分析所有基因片段的系统发育和分子特征，以血凝素重链（HA1）为参照。
2007年至2011年在青岛流行的H3N2流感病毒的血凝素（HA）基因形成了系统发育树的一个单主干。每个流行株都起源于上一个季节。全基因组进化分析发现，2009年至2010年期间重配病毒株流行，但2010年至2011年有两个流行株系列，显示出复杂的重配。与疫苗株相比，2007年至2011年病毒HA1蛋白的变异氨基酸分别为8个、6个、6个、8个和11个，涉及13个抗原位点。M2蛋白的序列分析表明，分离出的H3N2流感病毒在氨基酸位点31发生突变，从丝氨酸变为天冬酰胺（S31N）。2007年至2011年在青岛分离的H3N2流感病毒的HA1基因与全球流行株具有相似的系统发育树。序列比较和抗原性分析发现，A/青岛/F521/2011株中存在H3N2和A/H1N1的共同感染。
2007年至2011年在青岛流行的H3N2流感病毒各片段的进化特征复杂。
