天津地区夏季1例季节性H3N2亚型流感NA基因特异性分析

Specificity analysis of NA gene of a seasonal H3N2 subtype influenza in summer in Tianjin

目的分析1例天津地区夏季季节性H3N2亚型流感感染病例中NA基因的变异情况。方法分离病毒毒株,提取核酸,经逆转录聚合酶链反应(RT-PCR)方法扩增NA基因,获得的测序结果与中国地区各地毒株进行同源比对,使用生物信息软件绘制种系发生树,翻译后序列与WHO推荐的2014年-2015年疫苗株A/Texas/50/2012的NA氨基酸序列进行比对。结果 NA基因进化树分析表明,该毒株与2011年-2013年广东、杭州、中山等地区毒株集中于一支,与2014年-2015年疫苗株比对共有3个位点的氨基酸发生变化。该毒株未出现耐药位点的变异。结论本次研究所分离毒株与2014年-2015年疫苗株比对,其NA基因有变异,但未发现耐药位点的变异。

Objective To analyze the NA genetic mutation of a patient infected by seasonal H3N2 influenza virus in Tianjin in summer. Methods The strains were isolated from seasonal H3N2 influenza virus, and the NA gene was amplified by reverse transcription- polymerase chain reaction（ RT- PCR） and sequenced. The sequences results were compared with the strains from areas of China for consanguinaty. Using biological information software to draw a phylogenetie tree, and after transmit, the sequence were compared with the amino acid sequence of vaccine strain NA A/Texas/50/2012 recommended by WHO during 2014 -2015. Results The analysis of NA gene evolutionary tree showed that the strain and the strains from Guangdong, Hangzhou, Zhongshan and other regions was the same one during 2011 -2013, and compared with the strains during 2014 -2015, the amino acid changes happened on three sites. The strain showed the variation of drug resistance sites. Conclusion The NA gene of the strain in this study was found to be a variation, compared with the vaccine strain during 2014 -2015, but the variation of drug resistance sites was not found.