山西省武乡县1株白蛉携带病毒(SXWX1816-2)的分离与鉴定

Isolation and identification of a sandfly-borne virus(SXWX1816-2)in Wuxiang county,Shanxi province,China

目的调查山西省武乡县白蛉标本携带病毒的种类及其流行情况。方法2018年6月在山西省武乡县采集白蛉标本,使用实验室保存的金黄地鼠肾细胞(BHK-21细胞)和白纹伊蚊卵细胞(C6/36细胞)2种细胞系进行病毒分离,阳性分离物经病毒RNA提取、cDNA文库制备后,进行病毒基因扩增与核苷酸序列测定及系统进化分析。结果SXWX1816-2病毒分离株可引起哺乳动物细胞(BHK-21细胞)病变,但是对昆虫细胞(C6/36细胞)并不引起病变。病毒基因组核苷酸序列测定和分析结果显示该病毒M基因和S基因编码区核苷酸序列长度分别为4089和1611 nt;病毒M基因和S基因核苷酸/氨基酸序列同源性分析和分子遗传进化分析结果均表明SXWX1816-2分离株隶属于白纤病毒科白蛉病毒属,并与我国此前分离的武乡病毒(Wuxiang virus,WUXV)的同源性最高,病毒基因分子遗传进化关系最近。结论明确了我国白蛉分离病毒(SXWX1816-2)的分类地位,研究结果为我国吸血昆虫携带病毒,特别是白蛉携带和传播病毒的研究提供了重要的基础数据。

Objective To investigate the species and prevalence of viruses carried by sandfly specimens in Wuxiang county,Shanxi province,China.Methods Sandfly specimens were collected in Wuxiang county,Shanxi province in June 2018,and virus isolation was conducted using two cell lines of golden hamster kidney cells(BHK-21 cells)and Aedes albopictus egg cells(C6/36 cells)preserved in the laboratory.The positive isolate was subjected to viral RNA extraction and cDNA library preparation,followed by viral gene amplification,nucleotide sequence determination,and phylogenetic analysis.Results The SXWX1816-2 strain caused cytopathic effects in mammalian cells(BHK-21 cells),but no cytopathic effect in insect cells(C6/36 cells).The results of nucleotide sequence determination and analysis of the virus genome showed that the lengths of nucleotide sequences in the coding region of M and S genes of the virus were 4089 and 1611 nt;the results of nucleotide and amino acid sequence homology and phylogenetic analysis of M and S genes of the virus showed that the SXWX1816-2 strain belonged to the Phlebovirus genus from the Phenuiviridae family,which shared the highest homology and closest phylogenetic relationship with Wuxiang virus(WUXV)previously isolated in China.Conclusions This study clarifies the taxonomic status of the virus(SXWX1816-2)isolated from natural sandflies in China.The results provide important basic data for the research on viruses carried by blood-sucking insects in China,especially the virus carried and transmitted by sandflies.