猪流行性腹泻病毒YL株分离鉴定及仔猪感染试验

Isolation,Identification and Pathogenicity Testing of Porcine Epidemic Diarrhoea Virus YL Strain

从腹泻仔猪肠道组织中分离获得猪流行性腹泻病毒(PEDV)地方分离株,并对其致病性进行初步分析。对陕西某养殖场采集有腹泻症状3~5日龄仔猪的十二指肠,经RT-PCR检测为PEDV核酸阳性。将阳性样品处理后接种Vero细胞进行病毒分离,并对分离毒株进行病毒含量测定、致病性试验。结果显示,分离到1株PEDV毒株(命名为YL株)。将分离的PEDV病毒液以不同滴度口服接种健康仔猪,2.0 mL/头,发现10^(5.5)TCID_(50)/mL剂量组接种1日后,100%(3/3)试验猪出现腹泻症状。

To obtain local isolates of porcine epidemic diarrhoea virus(PEDV)from the intestinal tracts of piglets and to gain a preliminary understanding of their pathogenicity,in this study,the duodenum of piglets with diarrhoeal symptoms from 3 to 5 days of age was collected from a farm in Shaanxi,China,and the results of RT-PCR showed PEDV positive.The suspected positive samples were inoculated into Vero cells for virus isolation,and the isolated F5-generation viruses were subjected to RT-PCR detection,neutralisation test,viral content determination and pathogenicity test.The identification results showed that the isolated strain had the correct target gene and high viral content,and it was a specific strain against PEDV.We successfully isolated a strain of porcine epidemic diarrhoea virus(PEDV),named YL strain.The isolated PEDV virus solution was orally inoculated into healthy piglets at different levels,2.0 mL/head.It was found that 100%(3/3)of the test pigs showed diarrhoea symptoms 1 day after inoculation in the 105.5 TCIDso/mL dose group.The results of this study showed that the isolated strain was porcine epidemic diarrhoea virus(PEDV)with a minimum challenge dose of 10^(5.5)TCID_(50)/mL and 2.0 mL/head orally.The results of this test can provide theoretical reference for the isolation and identification of PEDV.