Project Directorate on Foot and Mouth Disease, Mukteswar, India.
J Virol Methods. 2012 Oct;185(1):52-60. doi: 10.1016/j.jviromet.2012.05.029. Epub 2012 Jun 7.
Differentiation of infected from vaccinated animals (DIVA) is essential for effective control of foot-and-mouth disease (FMD) by vaccination. The antibody response against FMD viral non-structural proteins (NSPs) has been used widely for this purpose. Among all the NSPs, the 3ABC polyprotein has been recognized as the most appropriate indicator for DIVA. In this study, mutated full-length 3ABC polyprotein was expressed in a prokaryotic system and monoclonal antibody against the recombinant protein was developed. A competitive ELISA (C-ELISA) for DIVA was standardized for different species of livestock animals using recombinant 3ABC and monoclonal antibodies. The diagnostic sensitivity and specificity of the assay were estimated by testing a panel of known serum samples consisting of sera from naive, vaccinated and infected animals as 86.9% with 66.4-97.2 (95%) confidence interval and 97% with 89.6-99.6 (95%) confidence interval respectively at 40% inhibition cut-off. The assay was validated further by testing sera from different livestock species collected at random from different parts of the country. The assay will provide a common method for testing sera from different species of livestock and wild animals. The C-ELISA is a sensitive and specific DIVA assay for FMD and can be used as a method for FMD control programme with vaccination.
区分感染动物和接种疫苗动物（DIVA）对于通过接种疫苗有效控制口蹄疫（FMD）至关重要。针对 FMD 病毒非结构蛋白（NSPs）的抗体反应已被广泛用于此目的。在所有 NSPs 中，3ABC 多蛋白已被认为是 DIVA 的最适宜指标。在这项研究中，突变全长 3ABC 多蛋白在原核系统中表达，并开发了针对重组蛋白的单克隆抗体。使用重组 3ABC 和单克隆抗体，针对不同畜种，标准化了用于 DIVA 的竞争 ELISA（C-ELISA）。通过测试由来自未接种、接种和感染动物的血清组成的已知血清样本的面板，评估了该检测方法的诊断敏感性和特异性，在 40%抑制截值时，其敏感性为 86.9%，置信区间为 66.4-97.2（95%），特异性为 97%，置信区间为 89.6-99.6（95%）。该检测方法在对来自全国各地的不同畜种的随机采集的血清进行进一步验证后，该检测方法将为测试来自不同畜种和野生动物的血清提供一种通用方法。C-ELISA 是一种敏感且特异的 FMD DIVA 检测方法，可作为接种疫苗的 FMD 控制计划的方法。
