风疹病毒分子流行病学研究

Molecular epidemiological study on rubella virus

目的 阐述风疹病毒 (RV)的遗传变异规律及分子流行病学特点。方法 利用RT PCR扩增RVE1基因 ,然后测序 ,并用DNASTAR软件包绘制系统发生树 ,以分析RV的分子流行病学特点。结果 测得RVJR2 3株E1基因的序列 ,与GenBank中包括 3株中国株在内的不同时间、地点分离的 30株病毒株一起绘制了系统发生树 ,比较了各株可产生HI抗体和中和抗体区的氨基酸变异情况。( 1)总体上RV的核酸、氨基酸序列高度保守。中国的 4株分离株遗传性质差别相对较大 ,其中 379株和BRD株构成了不同于其他 2 9株的基因Ⅱ型 ,就其遗传来源及生物学性状需进一步研究。 ( 2 )JR2 3株与英、美、日 2 0世纪 6 0年代流行株序列相近 ,其遗传来源可能为 2 0世纪 6 0年代世界流行株的中国衍生株 ,但具体的初始流行时间未知。结论 RV的流行有地域的差异 ,其分子流行病学特点与时间有关。因为人是RV的惟一宿主 ,所以人员的流动性 。

Objective To understand the hereditary and variant characteristics of rubella virus(RV), especially the strains isolated from China, investigating the epidemical trend and variation principle of RV. Methods The envelope glycoprotein E1 gene was amplified from rubella virus by RT-PCR. After sequencing, the gene sequence was handled by the software DNASTAR and the phylogenetic tree was drawn to analyze the molecular epidemiological characteristics of RV. Results The sequence of RV strain JR23 was sequenced, the phylogenetic tree was drawn taking 30 strains isolated at different times and locations in GenBank, including three strains from China as reference. The regions that encode the peptides which react with the HI antibody and the neutralization antibody were compared to show if there was any amino acid mutation in the sequence. (1) In general, the nucleotide and amino acid sequences of RV were highly conserved. The four strains isolated from China had relatively large variations. Strain 379 and strain BRD constituted genotype Ⅱ, which is different from the other 29 strains. Further study is needed to understand their heritable resources and biological characteristics. (2) Strain JR23 showed little difference from the strains that were epidemic during 1960s in UK,USA and Japan, so maybe it is the derivative strain of that in epidemic 1960s.But the accurate epidemic time is not known. Conclusion There are differences among areas and time in epidemics of rubella. The mobility and the region difference seem to be the key factors that affect the epidemic characteristics of RV.