新余地区2013年-2015年H3N2、B型流感病毒NA基因特性分析

Analysis of NA gene characteristics of H3N2 and B influenza viruses from 2013 to 2015 in Xinyu

目的对新余地区2013年-2015年H3N2、B型流感病毒神经氨酸酶(NA)进行基因特性分析,为流感防控和临床治疗提供科学依据。方法随机选择分离到的H3N2、B型流感毒株进行核酸提取,采用逆转录-聚合酶链反应(RT-PCR)扩增病毒NA基因后进行核苷酸序列测定,用DNAStar5.0,Mage5.0分子生物学软件对测序结果进行分析处理。结果与疫苗株A/Vitorvia/361/2011(H3N2)相比10株H3N2亚型分离株NA基因同源性均超过98.6%,但同源程度随时间跨度缓慢下降。在NA氨基酸序列上,所有H3N2分离株的二硫键位点和耐药相关位点均相同,分离株A/Jiangxi Yushui/1359/2015(H3)因在329位是苏氨酸(T),导致其糖基化位点和抗原决定簇与其它H3N2亚型毒株不完全相同。B-Yamagata系流感病毒中有60%(9/15)的毒株为BY-HA/BV-NA重配毒株;所有B型分离株NA蛋白的二硫键位点、糖基化位点和耐药相关位点均未发生改变,但NA抗原决定簇在两个谱系间差异较大。结论新余地区2013年-2015年所有分离株NA基因与相应疫苗株同源性较高。在NA氨基酸序列上除分离株A/Jiangxi Yushui/1359/2015(H3)外,其余分离株二硫键位点、糖基化位点和耐药相关位点在同(亚)型内是一致的;抗原决定簇在H3N2分离株间也是相同的但在B型不同系谱间差异相当大。所有分离株仍然显示出对神经氨酸酶抑制剂(NAIs)敏感,应该持续监测其变化情况。

Objective To analyze the gene characteristics of the neuraminidase（NA） of influenza A/H3N2 and B virus in Xinyu during 2013-2015,and to provide scientific evidence for prevention and clinical treatment of influenza. Methods Some strains of A/H3N2 and B virus were randomly selected for nucleic acid extraction,and Segments of the NA gene were amplified by one-step RT-PCR and then were sequenced. The sequence data obtained were analyzed with the assistant of DNA Star 5.0 and Mage 5.0 software. Results Compared with the vaccine strain A/Vitor/361/2011（H3N2）,the homology of the NA gene of the 10 H3N2 subtype isolates exceeded 98.6% respectively,but the degree of homology decreased slowly with the time. In the NA amino acid sequences,disulfide bond sites and drug resistance-related sites of all H3N2 isolates were identical,and there were differences in glycosylation sites and in antigenic determinants sites between the isolates strain A/Jiangxi Yushui/1359/2015（H3） and all other H3N2 strains because of threonine（T） at position 329. sixty percent（9/15） of the B-Yamagata influenza viruses are BY-HA/BVNA reassortants;The disulfide bond sites,glycosylation sites and drug resistance associated sites of all B strains were no changes change,but the antigenic determinants sites differed significantly between the two lineages. Conclusion The antigenic determinants are also identical among H3N2 isolates but vary considerably between B-type pedigrees. All isolates still show sensitivity to neuraminidase inhibitors（NAIs） and should be monitored continuously. In the Xinyu area,the NA genes of all isolated strains from 2013 to 2015,kept higher degree of sequence homology to their respective vaccine strains. Except for the isolated strain A/Jiangxi Yushui/1359/2015（H3）,the disulfide bond sites,glycosylation sites and drug resistance associated sites were identical in the same（sub） type. The antigenic determinants are also identical among H3N2 isolates but vary considerably between B-type pedigrees. All isolates still show sensitivity to neuraminidase inhibitors（NAIs） and should be monitored continuously.