一株传染性软化病病毒的分离和鉴定

病毒性软化病是一种严重影响蚕业生产的流行病,其病原为家蚕传染性软化病病毒(Bombyx moriinfectious flacherie virus,BmIFV)。本实验室在浙江省收集到具有软化病症状的家蚕幼虫,并分离纯化获得一株病毒。电镜观察到病毒粒子为直径26nm左右、无包涵体的球状颗粒。病毒添食四龄起蚕和五龄起蚕,分别在3~4d和5~7d出现明显症状和病变。纯化病毒SDS-PAGE条带与BmIFV蛋白相仿。病毒核酸鉴定为RNA,并可用套式RT-PCR扩增出特异性片段,测序发现片段序列和BmIFV日本坂城株的同源性为99.5%。由此可确定该病毒为BmI-FV,这是我国首次分离到该病毒,暂命名为BmIFV-CHN001。

Isolation and Identification of an Infectious Flacherie Virus from Silkworm,Bombyx mori in Zhejiang Province of China

Infectious flacherie virus(IFV)is the agent causing flacherie disease of silkworm.We collected the silkworms with suspective symptom in Zhejiang Province and a virus was isolated.Electron microscopy revealed the non-enveloped global particles that measured approximately 26nm in diameter.Feeding fourth instar and fifth instar with virus-smeared leaves,pathological changes were observed after 3-4d and 5-7d respectively.SDS-PAGE of purified virions showed resemblance to the typical protein bands of IFV.Genomic nucleic acid of the virus was identified to be RNA,when subjected to nested RT-PCR,specific amplified fragments were obtained.Subsequent analysis indicated the sequence of the virus shared a 99.5% similarity with the standard strain of IFV.It was the first IFV case discovered in China and the strain isolated was named BmIFV-CHN001.