犬瘟热病毒南京分离株的生物学特性鉴定

Identification of Biological Characteristics for CDV isolate in Nanjing

从南京地区临床诊断疑似为犬瘟热的病犬脑组织分离到 1株病毒 ,经鉴定为犬瘟热病毒 ( CDV) ,命名为 CDV-NJ1 5,对其培养特性、细胞毒力、血凝活性、抗原性、结构多肽和对犬的致病性进行了研究。结果表明 ,除 Vero外 ,CDV-NJ1 5还能在 MDCK、BHK-2 1、FE、DJRK、HEp-2等细胞系有限增殖 ,产生的 CPE特征与 Vero细胞类似 ,但不能在 PK1 5细胞系增殖。在 Vero细胞的 TCID5 0 和空斑形成单位分别为 1 0 - 5 .0 /m L和2 .4× 1 0 5 PFU/m L。参考株 CDV-Onderspoort的培养特性和细胞毒力基本与之相似 ;交叉中和试验表明 ,二者之间具有交叉反应和相同的抗原性 ;二者的结构多肽 NP蛋白和 F蛋白用特异性单克隆抗体免疫转印技术分析 ,未显示差异。动物回归试验表明 ,CDV-NJ1 5对犬表现出弱致病力。以上结果提示 ,该分离株是一持续性感染的弱毒株 。

One canine distemper virus(CDV) isolate was obtained by co cultivation of Vero cells with the brain tissue specimen taken from a dog clinically diagnosed as canine distemper in Nanjing. The isolate caused constant cytopathic effect(CPE) in Vero cells, which consisted mainly of cell fusion, syncytia and eosinophilic inclusion body formation. Following the examination of the immunoelectron microscope, typing of nucleic acid, etc. it was identified as CDV and then designated as CDV NJ15. The cell cultural property, cell virulence, hemagglutination activity, antigenicity, structural polypeptides and the pathogenicity to dogs were investigated. CDV NJ15 could propagate in MDCK, BHK21, HEp 2, DJRK and FE cell lines to different extent and produce CPE similar to that in Vero cells, but not propagate in PK15. In Vero cells, TCID 50 and PFU of the isolate were 10 5.0 /mL and 2.4×10 5.0 /mL, respectively. There was no distinct difference between the vaccine strain CDV Onderstepoort and NJ15 in host cell property and cell virulence. Both strains showed cross reaction in neutralization test and similar antigenicity. The viral NP and F proteins revealed the same patterns by Western Blotting with specific monoclonal antibodies. CDV NJ15 strains showed weak pathogenicity to native dogs.