首次从我国蚊虫中分离到类似广平病毒

First Isolation of Quang Binh-like Virus from Mosquitoes in China

为掌握云南省西双版纳州勐海县蚊媒病毒分布状况,用诱蚊灯采集蚊虫标本,用细胞培养法分离病毒,对阳性分离物进行分子生物学鉴定。2012年7月,在勐海县打洛镇采集蚊虫32批共1 468只,其中三带喙库蚊(Culex tritaeniorhynchus)28批1 383只,致倦库蚊(Culex quinquefascitatus)2批66只,按蚊(Anopheles)2批19只。用金黄地鼠肾细胞(Golden hamster kidney cell,简称BHK-21)和白纹伊蚊细胞(Aedes albopictus cell,简称C6/36)进行病毒分离,结果有2批三带喙库蚊标本(BNDL1205和BNDL1227)能引起C6/36细胞产生聚合病变,而不能引起BHK-21细胞病变。用黄病毒属特异性引物对这2株阳性分离物进行RT-PCR,扩增得到800bp左右的条带并进行核苷酸序列测定。对核苷酸序列的系统进化分析表明,这2株病毒与分离自越南的广平病毒(Quang Binh virus,QBV)VN180株亲缘性最近,处在同一进化分支;与VN180株的核苷酸同源性分别为83.4%和82.9%,而与既往国内外分离的18株蚊虫黄病毒的核苷酸差异较大。结果表明BNDL1205和BNDL1227病毒为类似QBV,此为国内首次报道。

Abstract：This study aims to investigate the distribution patterns of mosquito-borne viruses in Menghai County, Xishuangbanna Prefecture, Yunnan Province, China and to provide evidence for the prevention and control of mosquito-borne diseases. Mosquito samples were collected using mosquito lamps. Viruses were isolated from the samples by cell culture, and the isolates were identified by RT-PCR. The genomes of isolates were sequenced for phylogenetic analysis. In July 2012, a total of 1468 mosquitoes were captured in Daluo Town of Menghai County; they were divided into 32 pools, including Culex tritaeniorhyn- chus （28 pools, 1383 mosquitoes）, Culez quinquefasciatus （2 pools, 66 mosquitoes）, and Anopheles （2 pools, 19 mosquitoes）. Golden hamster kidney cells （BHK-21） and Aedes albopictus cells （C6/36） were used for virus isolation. The results showed that C6/36 cells were susceptible to two isolates recovered from Culez tritaeniorhynchus （BNDL1205 and BNDL1227）, with marked cytopathic effect （CPE） of cell fusion. By contrast, the two isolates could not cause CPE in BHK-21 cells. RT-PCR was performed for the two isolates using the flavivirus-specific primers FU2/cFD3, and a 800-bp amplicon was obtained from both of them. Phylogenetic analysis showed that the two isolates shared the same evolutionary branch with the Quang Binh virus （QBV） strain VN180, which had been isolated from Vietnam, with nucleotide sequence homologies of 83.4G and 82.9 %, respectively. However, there existed relatively large differences in nucleotide sequence between them and other Culex flavivirus strains previously isolated in China and other regions. In light of the similarity between the two isolates and QBV, BNDL1205 and BNDL122 were referred to as Quang Binh-like virus, which were first reported in China.