江苏省2007年麻疹野毒株基因特征分析

Molecular Epidemiology Analysis of Wild-type Measles Viruses Circulated in Jiangsu Province in 2007

目的阐明江苏省2007年流行的麻疹野病毒分离株的基因特征，为控制、消除麻疹提供依据。方法用Vero—Slam细胞从麻疹患者的咽拭子标本中分离麻疹病毒，通过逆转录-聚合酶链反应（RT-PCR）从分离到的麻疹病毒株中扩增出核蛋白（Nucleoprotein，N）基因羧基末端600个核苷酸片段，再对扩增产物进行核苷酸序列测定和分析，并以羧基末端450个核苷酸片段构建基因亲缘性关系树，进行核苷酸、氨基酸同源性分析。结果江苏省2007年分离的14株麻疹野病毒全部为H，基因型中的H1a基因亚型，在基因树上有多个分支。14株麻疹野病毒的核苷酸同源性为96．7％～100．0％，氨基酸同源性为94．0％～100．0％。与中国沪191麻疹疫苗株的核苷酸同源性为90．1％～91．6％，氨基酸同源性为84．7％～88．0％；与H2基因型代表株China94—1的核苷酸同源性为91．6％～93．4％，氨基酸同源性为88．0％～91．3％。结论江苏省2007年流行的麻疹野病毒优势基因亚型为H1a，与我国大陆其它省份流行的优势基因亚型相同。

Objective To illustrate the genetic characterizations and molecular epidemiology of wild-type measles viruses in Jiangsu province during the year 2007,and provide the scientific evidence for measles control and elimiantion. Methods Vero-SLAM cell was used for measles viral isolation,and total 14 measles viruses were isolated from the throst swabs of measles patients. Fragment of 600 nucleotide acids of the carboxyl end of nucleoprotein gene were amplified using reverse transcription-polymerase chain reaction （RT-PCR） method,and then the PCR prod- ucts were directly sequenced and analyzed. Phylogenetic tree was constructed based on 450 nucleo- tide acids of the carboxyl end of nucleoprotein gene, and homological analysis was performed at nucleotide acid level and amino acid level. Results Fourteen measles viruses isolated were all identified as H1 genotype, and all belonged to H1a sub-genotype in Jiangsu province at the year 2007. The homology at nucleotide acid level among them was between 96.7% and 100% ,and the homology at amino acid level among them was between 94.0% and 100%. Compared with S191 strain,the Chinese measles vaccine strain, the homology at nucleotide acid level was between 90.1% and 91.6%,and the homology at amino acid level was between 84.7% and 88.0%;Compared with H2 genotype,China 94--1,the homology at nucleotide acid level was between 91.6% and 93.4 %, and the homology at amino acid level was between 88.0 % and 91.3 %. Conclusion H1a sub-genotype was the predominant genotype of wild measles virus circulated in Jiangsu Province during the year 2007, which was the same as the dominant genotype prevalence in other provinces in China.