中国北方地区蜱携带荆门蜱病毒的分子流行特征分析

Analysis of molecular epidemic characteristics of Jingmen tick virus among ticks in northern China

目的通过对中国北方地区采集蜱中的荆门蜱病毒(Jingmen tick virus,JMTV)进行基因组扩增并进行系统进化分析,阐明中国北方地区JMTV的分子流行特征。方法采集蜱样本,制备蜱悬液提取总RNA,使用反转录-聚合酶链式反应(RT-PCR)进行JMTV检测和基因组扩增,与已知的JMTV进行序列比较及系统发生分析。结果通过对采集于3个省级行政区〔中国西北地区的新疆维吾尔自治区(新疆)博乐市、东北的辽宁省沈阳市和北京市昌平区〕的277只蜱样本进行JMTV筛查,获得阳性样本67只,阳性率为24.2%;并获得4株接近全长的JMTV基因组序列,系统进化分析显示:这4株病毒在节段1、节段2、节段4与已知的新疆啮齿类中发现的JMTV聚集在一个进化分支上;但在节段3构建的进化树中,2株病毒与新疆啮齿类JMTV聚集在一起,而另2株与中国其他地区的蜱源性JMTV聚集在一起,提示可能存在基因重排。结论同源性分析显示,新发现的4株JMTV与已知的中国地区JMTV同源性最高,具有遗传多样性。

Objective To investigate the molecular epidemic characteristics of Jingmen tick virus(JMTV)among ticks in northern China by genome amplification and phylogenetic analysis.Methods Ticks samples were collected to prepare tick homogenate and extract total RNA.RT-PCR was used for genome amplification of JMTV.Sequence comparison and phylogenetic analysis were performed.Results A total of 277 ticks collected from 3 provinces(Bole city in Xinjiang,Shenyang city in Liaoning,and Changping district in Beijing)were screened for JMTV,and 67 positive samples were observed,with a positive rate of 24.2%.Four strains of JMTV with nearly full-length genome were obtained.Based on the results of the phylogenetic analysis,the segments 1,2,and 4 of these 4 strains clustered with the rodent-borne JMTV from Xinjiang.The segment 3 of 2 strains clustered with the rodent-borne JMTV from Xinjiang,but the other 2 strains clustered with the tick-borne JMTV from other regions of China,which suggest the possibility of gene reassortment.Conclusion Based on the homology analysis,the newly discovered 4 JMTV strains have the highest homology with the known JMTV in China,with genetic diversity.