2002-2007年福建省麻疹野病毒的分离与基因特性分析

Measles Virus Isolation and Genetic Analysis in Fujian(2002-2007)

[目的]收集福建省流行的麻疹野毒株,分析麻疹野病毒的基因特征。[方法]应用B95a或Vero/slam细胞,从疑似病例的咽拭子或尿液标本分离麻疹病毒,用RT-PCR方法扩增分离株病毒的N基因3＇端450个核苷酸片段,分析其基因型别及遗传特征。[结果]2002年、2006-2007年共从5个设区市分离了14株麻疹野病毒,均为H1a基因亚型。14株病毒核苷酸同源性为97.8%-100%,在遗传树图中分属于4个独立分支,具有不同的来源。福建省分离株与H1基因型中国代表株、H2基因型及疫苗株S191相比,与S191差异性最大（核苷酸同源性91.0%-92.0%,氨基酸同源性88.1%-90.1%）。MV06-32、MV07-30、MV07-39和MV07-46这4株间N基因3＇端450个核苷酸间同源性为100%,显示不同地区和年份来源的病毒株具有高度同源性。[结论]福建省目前监测到的麻疹野病毒均为H1基因型、H1a基因亚型,未发现其它型别;不同地区或同一地区内存在多传播链同时循环,也存在同一野病毒株可在不同地区、不同年份间持续循环传播。

[Objective] To accumulate measles strains and study the genetic characteristics in Fujian（2002-2007）.[Methods] Measles viruses were isolated from the throat swabs or urine specimens of the cases with B95a or Vero/slam cell line and identified by RT-PCR.The 450 nucleotide sequence of C terminus of the nucleoprotein（N） gene was amplified and directly sequenced.Phylogenetic analysis was performed.[Results] Totally 14 strains were isolated from 5 cities.All isolates were identified as H1 genotype,H1a sub-genotype,and belong to 4 different branches in the phylogenetic tree.The sequence identity matrix of the 14 isolates showed that the homology of nucleotide sequence was 97.8%-100.0%.The homology of nucleotide and amino acid sequences were 91.0%-92.0% and 88.1%-90.1% respectively,compared with that of S191.The 4 strains of MV06-32,MV07-30,MV07-39 and MV07-46 had the same 450 C terminus sequences which were isolated from different years and cities.[Conclusions] H1a sub-genotype is pre-dominant genotype of wild virus circulated in Fujian from 2002 to 2007,but other sub-genotypes were not found.There are several different transmission chains caused measles co-circulations in the same or different cities in Fujian and there is one kinds of wild virus which could induce measles epidemic in different cities for several years.