内蒙古牙克石地区莫氏田鼠携带汉坦病毒的遗传特征分析

Abstract

目的 分析内蒙古牙克石地区莫氏田鼠携带汉坦病毒（HV）的遗传特征及其与汉滩病毒（HTNV）和汉城病毒（SEOV）型HV之间的关系，确定哈巴罗夫斯克病毒（KHAV）的自然宿主。方法 采用RT-PCR检测HV核酸、特异性引物扩增S、M基因并测序及进行序列分析。结果 共捕获52只莫氏田鼠，其中5只为HV核酸阳性，带毒率为9.62%。经PCR扩增，5份HV阳性样本获得全S基因片段，2份阳性样本全M基因片段；S基因片段由1848~1861bp组成，M基因片段由3662bp组成。核苷酸序列同源性分析显示，病毒与KHAV具有高度同源性（S基因片段为92.5%~96.4%，M基因片段为88.9%~95.4%），与其他型HV的差异较大。将核蛋白（NP）和糖蛋白（GP）氨基酸序列与HTNV和SEOV进行比较，NP具有一致的二级结构，GP存在明显的差异。用全S与全M的核苷酸序列构建系统进化树，这些病毒均与KHAV聚集在一起，构成一个独立的分支。KHAV分为2个小分支，核昔酸差异＞5.3%。结论 内蒙古牙克石地区存在KHAV的流行，莫氏田鼠是KHAV的自然宿主。

Objective To analyze the viral genetic characteristics of hantaviruses carried by Microtus maximowixzii in Yakeshi of Inner Mongolia Autonomous Region and its relationship with Hantaan virus（HTNV) and Seoul virus（SEOV) viruses as well as to identify the natural host of Khabarovsk virus（KHAV).Methods HV specific RNAs were detected by RT-PCR.Complete S and M segment were amplified from the RNA-positive samples.Phylogenetic analysis were performed to estimate the genetic characterization and the relationship with other hantaviruses.Results Fifty two Microtus maximowixzii voles were captured in Yakeshi areas.Of those voles,hanta-viral RNA was tested positive in 5 samples（9.62％).Complete S and M segments sequences were obtained from 5 and 2 lung samples,respectively.The complete S segment was consisted of 1848 to 1861 bp,and the M segment consisted of 3662 bp.These viruses were closely related to each other with 92.5％-96.4％ for the S segment sequences and 88.9％-95.4％ for the M segment sequences.They shared a higher identity with KHAV found previously in Yakeshi and KHAV of Russia.However,they were obviously different from the other hantavirus species.The 5 strains had the consistent secondary structure of nucleocapsid protein（NP) and glycoprotein（GP).When further comparing their secondary structures with those of HTNV and SEOV,our Results indicated that there were no obvious differences in NP between KHAV and both HNTV,SEOV but with obvious difference in GP.Based on the S and M segment sequences,phylogenetic analyses revealed that these 5 strains clustered together with KHAV and formed a distinct lineage.Furthermore,all known KHAV strains could be divided into two small branches with a nucleotide divergence more than 5.3％.Conclusion Our research data revealed that KHAV was highly endemic among Microtus maximowixzii in Yakeshi area which supported the notion that Microtus maximowixzii had been the natural host of KHAV in the area.