猫泛白细胞减少症病毒YX01株的分离鉴定及致病性分析

Isolation,Identification and Pathogenicity Analysis of Feline Panleukopenia Virus Strain YX01

用F81细胞从疑似感染猫泛白细胞减少症病毒(FPV)猫的组织样本中分离出1株FPV毒株,命名为FPV YX01株,通过电镜观察、血凝试验以及化学试剂(20%乙醚和0.1 mol/L HCl)处理,分析了FPV YX01株的生物学特性;基于VP2基因序列,分析了FPV YX01株的遗传进化,通过动物回归试验评价了该分离毒株的致病力。结果显示,FPV YX01毒株感染F81细胞后,细胞出现萎缩拉丝、脱落、生长缓慢等典型病变;电镜观察可见FPV YX01病毒粒子呈圆形,表面无囊膜结构,直径约25 nm,可被FPV特异性抗体识别;遗传进化分析发现,YX01毒株VP2蛋白中决定FPV血凝活性和毒力的关键氨基酸位点未发生突变,且YX01毒株与意大利EU498695毒株高度同源;动物回归试验显示,感染YX01毒株可引起猫出现食欲减退、腹泻、体温双相热、肠胀气、肝脏出血以及白细胞数量急剧减少等猫泛白细胞减少症的典型临床症状,同时病理切片可见肝脏和肠组织出血、炎性细胞浸润等现象。研究结果分离到1株具有较强致病力的FPV毒株YX01株,为FPV调查、检测、试剂研发及抗体制备提供了物质基础。

This study isolated a strain of feline panleukopenia virus(FPV)from tissue samples of a suspected FPV-infected cat with decreased white blood cells using F81 cells,named the FPV YX01 strain.The biological characteristics of the FPV YX01 strain were analyzed through electron microscopy,serum agglutination test,and treatment with chemical reagents(20%ether and 0.1 mol/L HCD.The genetic evolution of the FPV YX01 strain was analyzed based on the VP2 gene sequence.The pathogenicity of the isolated strain was evaluated through animal regression experiments.The results showed that the FPV YX01 strain caused typical pathological changes in F81 cells after infection,such as shrinkage,stretching,detachment,and slow growth.Under electron microscopy,FPV YX01 viral particles were shown to be round,without a membranous structure on the surface,with a diameter of about 25 nm and could be recognized by FPV-specific antibodies.Genetic evolution analysis found that the key amino acid sites determining FPV coagulation activity and virulence in the VP2 protein of the YX01 strain had not undergone mutations,and the YX01 strain was highly homologous to the Italian EU498695 strain.Animal regression experiments showed that infection with the YX01 strain caused typical clinical symptoms of feline panleukopenia,such as decreased appetite,diarrhea,biphasic fever,intestinal flatulence,severe reduction in white blood cell count,and liver bleeding.Pathological sections also showed bleeding and inflammatory cell infiltration in liver and intestinal tissues.In summary,this study isolated a highly pathogenic FPV epidemic strain YX01,providing a material basis for the study of FPV epidemiology,the development of diagnostic reagents,and the preparation of therapeutic antibodies.