State Key Laboratory of Veterinary Etiological Biology, National Foot-and-Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, China.
Virol J. 2021 Sep 26;18(1):193. doi: 10.1186/s12985-021-01663-4.
Foot-and-mouth disease (FMD) is a devastating animal disease. Anti-non-structural protein (NSP) antibody detection is very important for confirming suspected cases, evaluating the prevalence of infection, certifying animals for trade and controlling the disease.
In this study, a competitive chemiluminescence immunoassay (3B-cCLIA) was developed for the rapid detection of antibodies against NSPs in different species of livestock animals using the monoclonal antibody (mAb) 9E2 as a competitive antibody that recognizes NSP 3B.
The cut-off value (50%), diagnostic sensitivity (Dsn) (97.20%, 95.71%, and 96.15%) and diagnostic specificity (Dsp) (99.51%, 99.43%, and 98.36) of the assay were estimated by testing a panel of known-background sera from swine, cattle and sheep, respectively. The accuracy rate of the 3B-cCLIA was further validated and subsequently compared with that of two commercial diagnostic kits. The early diagnostic results showed that antibodies recognizing NSPs developed later (approximately 1-2 days) than antibodies recognizing structural proteins. Furthermore, anti-NSP antibody presence in animals vaccinated multiple times (false positives), especially cattle and sheep, was confirmed, and the false-positive rate increased with the number of vaccinations.
These results indicate that the 3B-cCLIA is suitable for the rapid detection of antibodies against FMDV NSP 3B in a wide range of species.
口蹄疫（FMD）是一种毁灭性的动物疾病。抗非结构蛋白（NSP）抗体检测对于确认疑似病例、评估感染流行情况、对动物进行贸易认证和控制疾病非常重要。
本研究使用单克隆抗体（mAb）9E2 作为竞争抗体，针对不同种属的家畜动物中的 NSP 建立了一种快速竞争化学发光免疫分析（3B-cCLIA）。
通过检测一组来自猪、牛和羊的已知背景血清，分别估计了该方法的截断值（50%）、诊断敏感性（Dsn）（97.20%、95.71%和 96.15%）和诊断特异性（Dsp）（99.51%、99.43%和 98.36%）。进一步验证了 3B-cCLIA 的准确性，并随后与两种商业诊断试剂盒进行了比较。早期诊断结果表明，识别 NSP 的抗体出现得较晚（约 1-2 天），而识别结构蛋白的抗体出现得较早。此外，还证实了多次接种（假阳性）的动物存在抗 NSP 抗体，尤其是牛和羊，且随着接种次数的增加，假阳性率也随之增加。
这些结果表明，3B-cCLIA 适用于广泛种属中 FMDV NSP 3B 抗体的快速检测。
