猪流行性腹泻病毒HBMC2012株的分离鉴定及其致病性研究

Isolation and identification of porcine epidemic diarrhea virus strain HBMC2012 and its pathogenicity in piglet

为从腹泻仔猪肠道内分离鉴定猪流行性腹泻病毒(PEDV)并明确其致病性,本文研究应用Vero-81细胞从腹泻仔猪小肠及其内容物中分离鉴定了一株PEDV(HBMC2012株),分析了其遗传变异特征,并将该病毒分离株经口腔感染5头3 d健康初生仔猪,观察其临床表现和病理变化,检测病毒在组织中的分布,分析病毒血症和经粪便排毒的动态。结果显示,分离的PEDV HBMC2012株可以引起明显的细胞病变,与目前国内及美国流行的PEDV株同源性高,与2010年之前的国内流行PEDV株、欧洲株CV777和韩国株DR13同源性低。该病毒株可以导致仔猪出现PED典型的临床症状与病理变化,病毒主要分布于空肠后端、回肠和十二指肠黏膜上皮细胞内,病毒血症和粪便排毒至少持续14 d。该研究结果为PEDV的致病机制和弱毒疫苗研究奠定了基础。

To isolate and identify porcine epidemic diarrhea virus （PEDV） from intestine tract of piglets suffered from diarrhea, Vero-81 cells were inoculated with the sample from small intestine or its contents. And a PEDV isolate named HBMC2012 was isolated and identified, and its genetic variation characteristics were analyzed. In addition, five healthy piglets in 3-day-old were infected orally with the isolate. Clinical symptoms, lesions were observed, and the distribution of virus in tissues, viremia and fecal virus shedding were detected. The results showed the HBMC2012 isolate induced obvious cytopathogenic effects in Vero-81 cells and, shared higher homology with prevalent PEDVs in China and the USA currently, but lower homology with prevalent PEDVs isolated before 2010, CV777 from Europe and DR13 from Korea. The isolate caused typical clinical symptoms and pathological lesions in neonatal piglets, and the lesions mainly distributed in mucosal epithelial cells of distal jejunum, ileum and duodenum. The viremia and viral shedding from faeces lasted for 14 days at least. The results lay a necessary foundation for the further studies of the pathogenic mechanism of PEDV.