福建省2012～2014年麻疹病毒核蛋白基因特征分析

Genetic Characteristics of Measles Virus Nucleoprotein in Fujian Province,2012-2014

目的了解2012~2014年福建省麻疹病毒核蛋白N基因的变化。方法应用描述性流行病学方法对2012~2014年福建省麻疹发病情况进行分析。使用Vero/h SLAM细胞对疑似麻疹病例的咽拭子标本进行麻疹病毒分离,经逆转录-聚合酶链反应（Reverse Transcript Polymerase Chain Reaction,RT-PCR）方法扩增麻疹病毒核蛋白N基因羧基末端450核苷酸片段,测序获得序列后进行遗传变异分析。结果 2012~2014年福建省共报告548例麻疹病例,包括1起麻疹爆发和1例麻疹疫苗相关病例。共获得64株麻疹病毒N基因羧基末端片段,经基因型鉴定1例为疫苗株A型,63例为野毒株H1a亚型。野病毒的核苷酸同源性为91%~99.4%,在遗传图谱上分化成两个分支Lineage 1和Lineage 2,两支系之间核苷酸同源性为96.7%~99.0%,氨基酸同源性为96.5%~99.1%。Lineage 1毒株主要分布于2012和2014年,Lineage 2毒株主要分布于2013年,同一年份存在两个分支病毒的同时传播。福建省与同时期中国地区麻疹流行株在N基因羧基末端核苷酸片段上有高度同源性。结论福建省流行的麻疹病毒基因型为H_（1a）亚型,并存在多地区两条麻疹病毒传播链交替流行的趋势。

Objective This study analyzed variation of the N genes of measles virus isolates in Fujian province,2012-2014.Methods The measles incidence during 2012-2014 in Fujian province was determined through descriptive epidemiological methods.Measles viruses were isolated from specimens from measles cases using Vero / h SLAM culture technique.450 nucleotide sequences of the C terminus of measles virus nucleoprotein（N） genes were amplified from the isolates using reverse transcript polymerase chain reaction（RT-PCR）.Results 548 measles cases were reported in 2012-2014,and among these cases was 1 measles outbreak and 1 measles vaccine related case.Fragments of C terminuses of N genes were obtained from 64 strains of measles virus; 1 strain was identified as genotype A vaccine strain,and63 strains were genotype H1a.The nucleotide homology among wild virus strains was 91%-99.4%,and showed evolution into 2 lineages（lineage 1 and 2） in the phylogenetic tree.The homology of nucleotides and amino acids between the 2 lineages were 96.7%-99.0% and 96.5%-99.1%,respectively.Most lineage 1 strains were from 2012 and 2014,and most lineage 2 strains were from 2013; viruses of the two lineages appeared to co-circulate in the same year.The homology of nucleotides between Fujian strains and strains in other regions of China was high.Conclusions The genotype of measles viruses circulatingin Fujian province was H1a, and showed transmission into 2 lineages of measles viruses that were seen in many areas.