摘要目的 了解2015年杭州地区麻疹病毒(MV)流行株的核蛋白基因特征.方法 收集2015年在杭州市儿童医院(麻疹定点收治医院)住院麻疹患儿中分离得到MV株共18株,用RT-PCR检测并对部分PCR扩增阳性的片段进行基因测序,绘制系统进化树进行同源性分析.结果 18株MV经基因测序及系统进化树分析后均为H1a亚型,与该型参考株China93-2﹑China93-4核苷酸同源性为98.65％～98.88％;与GenBank登记的Jiangxi.CHN/23.11的MV株核苷酸同源性高达99.55％～99.78％,具有高度同源性,属于同一分支.遗传距离分析表明:2015年分离株组内遗传距离最小,为0.000,2015年分离株和H1a型之间的组间遗传距离最小,为0.013,而2015年分离株、H1a型与A型的组间遗传距离均较大,分别为0.081及0.083.结论 2015年杭州及周边地区儿童MV野毒株的优势亚型为H1a亚型,且为同一传播链,未发现疫苗株及其他型别.

abstractsObjective To explore genetic characteristics of nucleoprotein of measles virus (MV) stains in Hangzhou areas in 2015 . Methods There were 18 MV strains collected from measles patients in Hangzhou Children's Hospital in 2015. The gene was amplified by reverse transcription-polymerase chain reaction(RT-PCR), and the positive PCR products were determined by DNA sequencing. Phylogenetic tree was draw for homology analysis. Results By gene sequencing and phylogenetic tree analysis, 18 MV strains were identified as H1a subtype. The nucleotide homology between this genotype and the reference strains (China93-2,China93-4) ranged from 98.65％ to 98.88％. The nucleotide homology between H1 genotype and Jiangxi. CHN/23.11 registered in the GenBank ranged from 99.55％ to 99.78％, and they belonged to the same branch. The result of genetic distance analysis revealed that the p-distance (0.000) within genotypes in 2015 was the smallest. The p-distance (0.013) between genotypes in 2015 and H1a strains was the smallest. The significant distances were found between genotype A (vaccine strain) virus and 2015 or H1a strains, which were 0.081 and 0.083, respectively. Conclusions H1a genotype is the ascendant subtype of the epidemic MV strains in Hangzhou and its peripheral areas in 2015. All the strains belong to the same chain of transmission. Neither the vaccine strain nor the other genotypes is detected.