论文部分内容阅读
目的分析2014~2015年宁波市H3N2流行性感冒(流感)的流行特征和流行株血凝素(HA)基因和神经氨酸酶(NA)基因的变异情况。方法选择宁波市2014~2015年流感流行期间分离的H3N2代表株17株,进行HA1基因和NA基因扩增、测定,用DNAstar的Meg Align序列分析软件进行分析处理。结果宁波市2014~2015年H3N2流感毒株HA1基因的核苷酸长度均为987 bp,编码329个氨基酸;NA基因的核苷酸长度均为1 410 bp,编码469个氨基酸。2014年H3N2流感病毒HA1基因与2015年相比该区域有10~12个氨基酸位点存在差异,其中有5个氨基酸位点涉及HA1区3个抗原决定簇,在158~160位氨基酸上增加了一个糖基化位点;NA基因发生了6~8个氨基酸位点的替换,2015年与2014年相比在245~247位增加了一个糖基化位点。在基因进化树上2014年与2015年的流行株也都形成了独立的分支。结论宁波市2014~2015年间H3N2流感病毒无论是HA1基因还是NA基因均产生了较大的变异,流感病毒的流行应与病毒的抗原性漂移有关。
Objective To analyze the epidemiological characteristics of H3N2 influenza (influenza) and the variation of hemagglutinin (HA) and neuraminidase (NA) genes in epidemic strains from 2014 to 2015 in Ningbo. Methods Seventeen strains of H3N2 isolated during the influenza epidemic in Ningbo from 2014 to 2015 were selected for amplification and amplification of HA1 and NA genes. The data were analyzed by DNAStar’s Meg Align sequence analysis software. Results The nucleotide length of HA1 gene of H3N2 influenza strain from Ningbo city in 2014-2015 was 987 bp, encoding 329 amino acids. The nucleotide length of NA gene was 1 410 bp, encoding 469 amino acids. In 2014, the HA1 gene of H3N2 influenza virus had 10 ~ 12 amino acid residues in this region compared with that of 2015. Five of the HA1 genes involved HA3 antigenic determinants and the amino acids 158-160 A glycosylation site; substitution of 6 to 8 amino acid residues in the NA gene, and a glycosylation site at 245 to 247 positions in 2015 compared to 2014; In the phylogenetic tree, the epidemic strains of 2014 and 2015 also formed independent branches. Conclusion There was a great variation in H3N2 influenza virus between HA and NA genes in Ningbo city from 2014 to 2015. The prevalence of influenza virus should be related to antigenic drift of virus.