细胞传代致弱的鹅细小病毒YG毒株致病性变化的研究

Pathogenicity Changes of Cell Attenuated Goose Parvovirus YG Strain

旨在观察细胞传代致弱的鹅细小病毒YG毒株对易感雏鹅的致病性变化。将鹅细小病毒(GPV)YG株在鹅胚成纤维细胞(GEF)和鸭胚成纤维细胞(DEF)上进行交替传代培养,病毒在细胞上传至第12代时,开始出现细胞病变;间接免疫荧光试验(IFA)检测发现,随着病毒感染时间的延长,感染细胞数量呈现先增加随后减少的变化趋势,感染后96h阳性细胞数量最多;病毒的滴度随着传代次数的增加而逐渐升高;当病毒传至第50代时,细胞适应毒株毒价为106.5 TCID50·mL-1;雏鹅致病性试验结果显示,第50代病毒毒力明显减弱。细胞传代致弱的GPV YG株所感染雏鹅死亡和发病率降低,且死亡雏鹅无鹅细小病毒病的特征性病变及临床表现。

This experiment was conducted to study pathogenicity changes in susceptible goslings of cell attenuated goose parvovirus YG strain.To obtain attenuated vaccine strain,goose parvovirus（GPV）YG strain was propagated alternately in goose embryo fibroblasts（GEF）and duck embryo fibroblasts（DEF）.Cells infected with YG strain began to induce cytopathogenic effect after12 passages.Results of indirect immunofluorescence assay（IFA）showed that the numbers of infected cells with green fluorescence increased with the time of infection,and the highest number of positive cells were obtained at 96hpost-infection.Virus titers increased with serial passages going and virus titer reached 10^6.5 TCID50·mL^-1 after passage 50.Compared to parental virus,the mortality and morbidity of goslings decreased obviously after challenged with virus passage 50.There were no observed characterized pathogenic changes or clinical symptoms of Derzsy＇s disease in goslings after challenged with passage 50 YG virus.