我国新疆首次检出西伯利亚型蜱传脑炎病毒

Detection of the Siberian Tick-borne Encephalitis Virus in the Xinjiang Uygur Autonomous Region,northwestern China

对新疆地区蜱传病毒类群进行调查,本研究利用Illumia深度测序技术对新疆全沟硬蜱体内的病毒小RNA分子进行筛查,从提取的蜱小RNA组份中共测得32 631条病毒特异性读序,77条读序与蜱传黄病毒基因组序列匹配,核苷酸数合计约占病毒基因组的3.8%~2.4%,其中32条读序与国内尚未发现的西伯利亚型蜱传脑炎病毒一致。为对上述结果进行确证,利用RT-PCR对此型病毒核酸进行检测,从蜱总RNA中分别扩增获得病毒包膜基因与基因组3′末端片段,测序比对表明上述片段序列与西伯利亚南部检出病毒高度近似,核苷酸与氨基酸似然率分别为97.2%~95.5%与99.4%~98.3%。综上所述,本研究利用基于深度测序的病毒筛查方法,首次从我国新疆蜱传脑炎疫源地检出西伯利亚型病毒,为下一步针对病毒的分离与流行病学调查提供了重要线索。

Until the recent emergence/re-emergence of human-pathogenic viruses in ticks,tick-borne viruses have been neglected as causative agents of human disease（particularly in China）.To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region（northwestern China）,we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks.We found 32,631 unique virus-matched reads.In particular,77 reads mapped to the tick-borne group within the genus of Flavivirus,and covered 3.8%-2.4% viral genomes.In addition,32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses（TBEV-Sib）which have never been reported in Chinese TBE loci.We confirmed the potential existence of TBEV-Sib by amplification（using reverse transcription-polymerase chain reaction）of genomic fragments from the envelope gene or 3′genomic terminus from the pools of examined ticks.Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%,respectively.In conclusion,we report,for the first time,detection of TBEV-Sib in the natural TBE loci of China.These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.