Mallick Smrutirekha, Mohapatra Jajati Keshari, Biswal Jitendra Kumar, Rout Manoranjan, Ranjan Rajeev, Samanta Reshama, Singh Rabindra Prasad
ICAR - National Institute on Foot and Mouth Disease, Bhubaneswar, 752050, Odisha, India.
Vet Res Commun. 2025 May 17;49(4):200. doi: 10.1007/s11259-025-10767-z.
Foot and mouth disease (FMD) is one of the most infectious viral diseases of cloven-footed animals which cause devastating global economic losses. FMD virus (FMDV) specific non-structural protein (NSP) antibodies are indicative of a current or past infection with any of the seven FMDV serotypes(O, A, C, Asia1, SAT1, SAT2, SAT3). In the present study, a monoclonal antibody (MAb) was developed against recombinant FMDV NSP 3AB3 (r3AB3) via hybridoma system and applied in a competitive enzyme linked immunosorbent assay (cELISA) for NSP antibody detection. The newly generated MAb #FMDV3AB-2E4 was identified as an IgG1 isotype that specifically binds to NSP 3B. A cELISA termed FMDV3AB-2E4 cELISA was developed using r3AB3 as the antigen and the MAb. Percent inhibition (PI) cut-off of the cELISA was determined by receiver operating characteristics curve analysis of 202 known FMDV-positive and 730 negative serum samples from multiple species (cattle, buffalo sheep, goat, pig and deer). At the selected cut-off value of 45 PI the cELISA exhibited diagnostic sensitivity (DSn) of 95.54% and diagnostic specificity (DSp) of 98.36% at 95% confidence interval. Compared to commercial PrioCHECK FMD NS test the DSn was 93.54% and DSp was 97.46% for bovine and caprine sera (n = 446) obtained from naïve, FMDV-infected and vaccinated animals. Concordance rate of new cELISA and extensively used in-house r3AB3 indirect ELISA was 96.61% for test results of 3016 cattle sera collected across multi-locations in India. The species independent NSP antibody test developed would be a useful tool in FMD control efforts in India and other countries.
口蹄疫（FMD）是偶蹄动物中传染性最强的病毒性疾病之一，会造成巨大的全球经济损失。口蹄疫病毒（FMDV）特异性非结构蛋白（NSP）抗体表明目前或过去感染过七种FMDV血清型（O、A、C、亚洲1型、南非1型、南非2型、南非3型）中的任何一种。在本研究中，通过杂交瘤系统开发了一种针对重组FMDV NSP 3AB3（r3AB3）的单克隆抗体（MAb），并将其应用于竞争性酶联免疫吸附测定（cELISA）中检测NSP抗体。新产生的单克隆抗体#FMDV3AB - 2E4被鉴定为IgG1同种型，可特异性结合NSP 3B。使用r3AB3作为抗原和该单克隆抗体制备了一种名为FMDV3AB - 2E4 cELISA的cELISA。通过对来自多个物种（牛、水牛、绵羊、山羊、猪和鹿）的202份已知FMDV阳性血清样本和730份阴性血清样本进行受试者工作特征曲线分析，确定了该cELISA的抑制率（PI）临界值。在选定的45 PI临界值下，该cELISA在95%置信区间的诊断敏感性（DSn）为95.54%，诊断特异性（DSp）为98.36%。与商业PrioCHECK FMD NS检测相比，对于从未接触过FMDV、感染过FMDV和接种过疫苗的牛和羊血清（n = 446），DSn为93.54%，DSp为97.46%。对于在印度多个地点收集的3016份牛血清的检测结果，新的cELISA与广泛使用的内部r3AB3间接ELISA的符合率为96.61%。所开发的不依赖物种的NSP抗体检测方法将成为印度和其他国家口蹄疫防控工作中的有用工具。
