我国分离的XJ-90260病毒鉴定为西方马脑炎病毒

XJ－90260病毒是从新疆乌苏县境内采集的赫坎按蚊中分离到的一株病毒，病毒的鉴定结果显示：XJ－90260病毒可引起BHK－21细胞病变，表现为圆缩，脱落；可引起Vero细胞病变，表现为圆缩，破碎，脱落；可以在C6／36细胞中增殖，但不引起细胞病变。对3日龄小白鼠2－3天致死，对3周龄小白鼠3－4天致死。该病毒株对酸、乙醚敏感，抵抗5－氟脱氧尿苷。病毒与甲病毒组特异性免疫腹水起反应，与乙型脑炎病毒及布尼亚病毒组特异性免疫腹水不反应。进一步的分子生物学鉴定表明，该毒株基因组3′非编码区（ntranslated region,UTR）核苷酸序列具有典型的西方马脑炎病毒特征，与标准西方马脑炎病毒的首次报导，有重要的流行病学意义。我国9省区，886份血清的流行病学调查显示，该病毒抗体阳性血清24份，阳性率为2.71%。其中新疆（8／157），河南（6／76）、甘肃（5／94）三省区抗体阳性数较多，占总阳性数的79.2%(19/24)。

XJ-90260 Virus Isolated in China Was Identified as Western Equine Encephalitis Virus

In 1990,XJ-90260 virus was isolated from a pool of Anopheles hyrcanus species captured from Wusu County,Xinjiang Province of China.The virus was identified systematically in our laboratory.XJ-90260 virus produced cytopathic effect on BHK and Vero cells but not on C6/36 cell.The virus also caused morbidity and mortality in three-day-old and three-week-old mice.The virus was sensitive to acid and ether but resistant to 5-FudR. Serologically,the virus reacted with alphavirus group-specific polyclonal antibodies,but not reacted with Japanese encephalitis virus specific and Bunyavirus group-specific polyclonal antibodies.A pair of specific primers were used to amplify the section of E1-3' UTR of XJ-90260 virus by RT-PCR and it was sequenced and compared with the same region of the other alphaviruses. We made phylogenetic analysis of 3'UTR sequence of XJ-90260 virus.The phylogenetic trees indicated that XJ-90260 virus was most homologous with WEE virus and most closely related to WEE virus Y62-33 and TBT strains.This results demonstrated that XJ-90260 virus is a WEE virus.ELISA had been adapted to detect XJ-90260 virus polyclonal antibodies in 886 sera from nine provinces in China.It was found that there were 24 positive sera(2.71%). Perhaps XJ-90260 virus may play the role in viral encephalitis,that will be of great significance in epidemiology.