建国后首次登革热暴发分离的2株登革4型病毒prM和E基因序列测定及其系统发生分析

Sequence determination and phylogenetic analysis of two dengue virus type 4 strains isolated in the first outbreak of dengue fever after the foundation of the People's Republic of China

目的对建国后1978年广东佛山首次暴发登革热流行时从患者急性期血液中分离到的两株登革4型病毒(78-42、78-56)进行其分子特征研究并了解其可能来源。方法用Vero细胞培养1978年分离自广东佛山登革热病人的78-42、78-56两病毒株,RNA抽提后RT-PCR法扩增prM、E区基因,克隆至pGEM-TEasy载体后测序;利用DNASTAR软件预测其氨基酸序列并与其他国内外登革4型病毒株序列比较;运用CLUSTALX1.83和MEGA3.1软件绘制系统发生树。结果78-42、78-56两株高度同源,prM、E基因序列和氨基酸序列与其他登革4型病毒同源性很高并证实为登革4型毒株,与印度尼西亚和马来西亚分离株同属基因IIA亚型,核苷酸同源性与印尼ID1973株最高。结论78-42、78-56两新分离病毒株为建国后首次分离到的登革4型毒株,其来源最可能来自印度尼西亚。

Two dengue virus type 4 strains, 78-42 and 78-56, isolated from blood of patients during the first outbreak of dengue fever in Foshan, Guangdong province in 1978, were used for sequence study. The viruses were cultivated in Vero cell culture and the RNA of the viruses was extracted,in which the prM and E gene were amplified by RT-PCR and cloned into pGEM-T Easy vector and then sequenced. The amino acid sequences were deduced and the two strains were aligned with other dengue virus type 4 strains using DNASTAR. The phylogenetic tree was drawn with the soft of CLUSTALX1. 83 and MEGA3.1. The results showed that the PrM and E genes and the deduced amino acid sequences of the two strains were highly homogeneous between each other and with the other dengue virus type 4 strains. These two strains were proved to be dengue virus type 4 strains and belong to genotype 4 IIA with Indonesian and Malaysian isolates. The nucleotide homology of the two viruses was highest with Indonesia ID 1973 strain than the others, indicating that the origin of 78-42 and 78-56 strains may be derived from Indonesia.