患病中国大鲵中分离到一株虹彩病毒及其特性的研究

从陕西某大鲵养殖场患病的大鲵体内分离到一株病毒。患病大鲵以体表溃疡,特别是肢体远端溃烂为主要临床特征。该病毒于10℃~30℃能在BF-2(Caudal trunk cells of blue-gillfry)、CO(Gorad cells of grass carp)、CHSE(Embryo cells of Chinook salmon)、FHM(cells of fathed minnow)等细胞中较好地增殖,最适生长温度为25℃~30℃。病毒对氯仿、热、pH3、pH10敏感,DNA抑制剂5-氟-2′-脱氧尿苷(5-fluro-2-′deoxyuridine,FUDR)能抑制病毒在细胞中的增殖,提示该病毒是有囊膜的DNA病毒。经电镜观察,在感染了病毒的细胞切片中可见到大量直径约130~150 nm有囊膜的六角形病毒颗粒成晶格排列在细胞质里,病毒呈典型的虹彩病毒形态。抽提病毒核酸后进行PCR扩增,用已知蛙病毒主要衣壳蛋白(MCP)基因的保守序列设计的引物能扩增出431bp的片段。扩增的片段测序后,和已知的几种蛙病毒属成员的主要衣壳蛋白基因中的相应片段进行比对,相似性在96%以上。血清学试验结果显示该病毒和IPNV(Infectious pancreatic necrosis virus,IPNV)、GCRV(Grass carp reovirus,GCRV)、SVCV(Spring viraemia of carp virus,SVCV)I、HNV(Infectious hematopoietic necrosis virus,IHNV)在血清学上没有相关性。以上结果提示该病毒可能是虹彩病毒科蛙病毒属的成员,暂时命名为大鲵虹彩病毒(Andrias davidianus iridovirus,ADIV)。该病毒与大鲵发病的关系有待进一步研究。

Isolation and characterization of an iridovirus from sick giant salamander (Andrias davidianus)

A virus was isolated from cultured sick giant salmander (Andrias davidianus ) in a farm, Shanxi Province, China. Skin ulceration and necrosis of the distal limbs are main clinical symptoms. Virus propagated and caused CPE at 10 degrees C to 30 degrees C in BF-2, CO, CHSE, FHM cells. The optimum condition of replication was in BF-2 cells at 25 degrees C. The virus was proved to be senstive to chloroform, heat, pH3 and pH10 treatment. Viral replication was inhibited by 5-Fluoro-2-deoxyuridine (FUDR). These results indicated that the virus possessed an envelope and DNA as the genome. Electron-microscopic observation of thin-section showed numerous hexagonal viral particles measuring 130 nm to 150 nm in diameter orderly arranged in a lattice form in cytoplasm of BF-2 cells. The particles showed typical iridovirus morphology. A 413 bp fragment was amplified from the viral main capsid protein gene by PCR. The fragments was sequenced and analysed. The results showed the isolate shared more than 96% nucleotide identity with some Ranaviruses. We suggested that this virus was named as Andrias davidianus iridovirus (ADIV) tentatively.