西昌市虫媒病毒核酸检测及其序列分析

Nucleic acid detection and sequence analysis of arboviruses in Xichang

目的了解四川省西昌市蚊虫样本中虫媒病毒的流行情况,丰富四川省西南部地区虫媒病毒的活动规律和病毒遗传特征的研究数据。方法2018年6月对采集自西昌市3个村不同猪圈环境中的三带喙库蚊提取核酸,使用云南环状病毒属、版纳病毒属、西藏环状病毒属(S7、S10)、黄病毒属、甲病毒属的特异性引物进行PCR检测,对阳性产物克隆测序并进行序列分析。结果共采集到蚊虫9012只,其中三带喙库蚊为优势蚊种,对采集到的三带喙库蚊分88批次进行扩增,分别检测出2株乙型脑炎病毒(JEV)、7株版纳病毒(BAV)、7株西藏环状病毒(TIBOV)和1株云南环状病毒(YOUV),序列分析结果显示,17株新检测病毒株均与云南分离株遗传关系接近,2株JEV位于GⅠ-b进化支;7株BAV为A2进化分支;7株TIBOV中,6株位于同一进化支;1株TOUV与云南分离株在同一进化支。结论西昌市的三带喙库蚊中存在携带JEV、BAV、YOUV及TIBOV等病毒的可能,其中JEV为GⅠ-b型病毒,BAV为A2型,为西昌市虫媒病毒的检测及分析提供了数据支持。

Objective To understand the prevalence of arboviruses in mosquito samples in Xichang City,Sichuan Province,and enrich the data of arbovirus activity and genetic characteristics in southwestern Sichuan Province.Methods In June 2018,the nucleic acid was extracted from Culex tritaeniorhynchus mosquitoes collected from different pigsties in three villages and suburbs of Xichang City.The specific primers of Yunnan orbivirus,Banna virus,Tibet orbivirus(S7,S10),Flavivirus and alphavirus were used for quantitative polymerase chain reaction examination,and the positive product was cloned for sequencing analysis.Results A total of 9012 mosquitoes were collected,of which Cx.tritaeniorhynchus was the dominant species.A number of 88 batches of these mosquitoes were amplified,and 2 strains of Japanese encephalitis virus(JEV),7 strains of Banna virus(BAV),7 strains of Tibet orbivirus(TIBOV)and 1 strain of Yunnan orbivirus virus(YOUV)were detected,respectively.By the results of cluster analysis and evolutionary tree analysis,the 17 newly found virus strains were close to the Yunnan isolates,and 2 JEV strains were located in the GI-b clade.The other 7 strains of BAV were A2 evolutionary clades.Of the 7 TIBOV plants,6 were located in the same clade.One TOUV was in the same clade as the Yunnan strain.Conclusions Culex tritaeniorhynchus mosquitoes in Xichang city might carry JEV,BAV,YOUV and TIBOV,among them JEV was GI-b type and BAV was A2 type.The results provide data supporting the detection and analysis of arboviruses in Xichang city.