Shan Ying, Liu Yajie, Liu Ziqi, Li Guowei, Chen Cong, Luo Hao, Chen Yunlu, Guo Ningning, Shi Xingfen, Zhang Xian, Fang Weihuan, Li Xiaoliang
a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China.
b Xiazhuhu Wetland Scenic Management Committee, Deqing, Huzhou, P.R. China.
Can J Microbiol. 2019 May;65(5):343-352. doi: 10.1139/cjm-2018-0240. Epub 2019 Feb 1.
Porcine epidemic diarrhea virus (PEDV) causes severe infectious diseases in all ages of swine and leads to serious economic losses. Serologic tests are widely accepted and used to detect anti-PEDV antibodies that could indicate PEDV infection or vaccination. In this study, PEDV recombinant S1 protein (rS1) was expressed with the Bac-to-Bac system and purified by nickel-affinity chromatography. An indirect enzyme-linked immunosorbent assay based on rS1 (rS1-ELISA) was then developed and optimized by checkerboard assays with serial dilutions of antigen and serum. Serum samples from 453 domestic pigs and 42 vaccinated pigs were analyzed by the indirect fluorescent antibody (IFA) test and rS1-ELISA. Taking IFA as a gold standard, rS1-ELISA produced a high sensitivity (90.7%) and specificity (94.6%) by a receiver operating characteristic (ROC) curve. In addition, ROC analysis also revealed that rS1-ELISA was consistent with IFA (area under the curve 0.9583 ± 0.0082). This rS1-ELISA was then applied to antibody detection in inactivated PEDV vaccinated pigs. The antibody could be detected 2-4 weeks after the first inoculation. These results indicated that the rS1-ELISA established in this study provides a promising and reliable tool for serologic detection of anti-PEDV IgG antibodies in infected or vaccinated pigs.
猪流行性腹泻病毒（PEDV）可导致各年龄段猪只发生严重传染病，并造成严重经济损失。血清学检测被广泛接受并用于检测抗PEDV抗体，这些抗体可表明PEDV感染或疫苗接种情况。在本研究中，利用杆状病毒表达系统表达了PEDV重组S1蛋白（rS1），并通过镍亲和层析进行纯化。随后开发了基于rS1的间接酶联免疫吸附测定法（rS1-ELISA），并通过对抗原和血清进行系列稀释的棋盘滴定法进行优化。采用间接荧光抗体（IFA）试验和rS1-ELISA对453头家猪和42头接种疫苗猪的血清样本进行分析。以IFA作为金标准，通过受试者工作特征（ROC）曲线分析，rS1-ELISA显示出高敏感性（90.7%）和特异性（94.6%）。此外，ROC分析还表明rS1-ELISA与IFA一致（曲线下面积为0.9583±0.0082）。然后将该rS1-ELISA应用于灭活PEDV疫苗接种猪的抗体检测。首次接种后2-4周可检测到抗体。这些结果表明本研究建立的rS1-ELISA为感染或接种疫苗猪抗PEDV IgG抗体的血清学检测提供了一种有前景且可靠的工具。
