首次从新疆的蜱和病牛血清分离到新环状病毒

First Isolation of New Orbivirus (BANNA) from Ticks and Infected Cattle Sera in Xinjiang

1990年3～8月从新疆北部和西部地区采集全沟硬蜱(Ixodes persulcatus)、银盾革蜱(Dermacentor niveus)、森林革蜱(D.silvarum)、边缘革蜱(D.marginatus)、草原革蜱(D.nuttalli)、刻点血蜱(Haemaphysalis punctata)、残缘璃眼蜱(Hyalomma detritum)等共2132只,分离病毒17株;采集病牛血清3份,分离病毒1株。从两地区共分离病毒18株。经血清学鉴定,该类病毒与披膜病毒科(Togaviridae)、黄病毒科(Flavirdae)、布尼亚病毒科(Bunyavirdae)某些病毒的免疫腹水及免疫血清都不发生反应。与新环状病毒(BANNA)的免疫腹水、免疫血清及酶标单克隆抗体(McAb)发生反应,中和指数为4.22～5.03。电镜观察病毒为球形无囊膜颗粒,直径为63～69nm,核衣壳直径为49～54nm。超薄切片在感染细胞中见到大量颗粒状包涵体,磷钨酸负染可见到排列整齐的壳粒结构,显示了典型的环状病毒形态特征。新分离的病毒对酸、氯仿、胰蛋白酶及热敏感;抵抗乙醚和5-碘脱氧尿苷。该病毒可引起白纹伊蚊(Aedes albopictus)传代细胞 C_6l_(36)细胞收缩、融合、脱落及颗粒增多等病变;感染传代细胞Vero株及BHK-21株未见明显的细胞病变。感染2～4日龄乳小白鼠及2～4周龄小白鼠,均无明显发病症状。初步鉴定证实,新分离病毒属新环状病毒(BANNA)。

From March to August 1991,17 strains of virus were isolated from 2 132 ticks of the species Ixodes persulcatus, Dermacentor niveus, D. silvarum,D. marginatus, D. nuttalli, Haemaphysalis punctata and Hyalomma detritum collected from the north and west parts of Xinjiang, and one strain of virus was isolated from 3 infected cattle sera. Serological identification showed that the isolates were un-reactive to immune ascites and immune sera of viruses of the Togaviridae, Flaviridae and Bunyaviridae families.However, they were reactive to immune ascites, immune sera and enzyme labeled monoclonal antibodies of the new orbivirus (BANNA) with neutralization indexes of 4.22-5.03. Electron microscopy revealed that the isolated viruses were unenveloped spherical particles, 63-69nm in diameter, and the nucleocapisid was 49-54nm in diameter. Ultrathin section of the infected cells showed numerous inclusion bodies, capsomers were seen regularly arranged when negatively-stained with phosphotungstic acid, which were morphologically characteristic of the genus orbivirus.The isolates were sensitive to acid, chloroform, trypsinase and heat,but resistant to 5-iodoxidine (IDU). Pathogenies such as contraction, fusion.exfoliation and granular multiplication were observed when C6 / 36 cells were infected with the new isolates, however, no pathogeny was observed obviously when Vero and BHK-21 cells were infected, and no obvious pathogeny was seen to 2-4-day suckling mice and 2-4-week mice. The isolates were therefore prelimilary identified as new orbivirus (BANNA).