Manjunatha Reddy Gundallahalli Bayyappa, Sudeep Nagaraj, Apsana Rizwan, Sumana Krishnappa, Sai Mounica Pabbineedi, Yogisharadhya Revanaiah, Balamurugan Vinayagamurthy, Rajeswari Shome, Sathish Shivachandra Bhadravati
ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Post Box No. 6450, Yelahanka, Bengaluru, Karnataka, 560119, India.
Vet Res Commun. 2025 Jan 27;49(2):90. doi: 10.1007/s11259-025-10656-5.
Sheeppox and Goatpox are highly contagious transboundary viral diseases of sheep and goats caused by Capripoxvirus, respectively. This study describes the development of indirect ELISA and its serodiagnostic potential as an alternative to the gold standard serum neutralization test (SNT). The homologue of vaccinia virus, ORF 117 (A27L) gene of the Romanian Fenner (RF) strain of Sheeppox virus (SPPV) was used for producing the full-length recombinant A27L (rA27L) protein (∼22 kDa) in a prokaryotic expression system. The immunogenic potential of purified rA27L was confirmed by detecting its specific reactivity with SPPV hyperimmune sera in Western Blot analysis. An indirect ELISA based on rA27L was developed and optimized. In comparison to SNT, the rA27L-ELISA assay exhibited a diagnostic specificity of 96% and 98%, while the sensitivity was 98% and 97%, with sheep and goat sera, respectively. No cross-reactivity was noted with other transboundary diseases such as Orf, Foot-and-Mouth disease, Peste des Petits Ruminants, Haemorrhagic septicemia and Brucella. A total of 508 serum samples were tested in total for the preliminary analysis. Among these, seropositivity rates for sheep (n = 270) and goats (n = 238) were 31.85% and 47.47%, respectively. Further, to determine accuracy of developed test a total of 1731 serum samples were analyzed from the states with high small ruminant populations in India which included Andhra Pradesh, Telangana, Karnataka, West Bengal, and Gujarat. Overall seropositivity recorded were 24% in sheep and 19.12% in goats. Among the population of sheep and goats examined, the females and animals in the age group of 1-2 years showed high Capripoxvirus antibodies. This study highlighted the potential utility of rA27L protein as a safe and alternative serodiagnostic reagent, unlike the SNT, for serosurveillance and seromonitoring of Capripoxvirus infection in sheep and goats.
绵羊痘和山羊痘分别是由山羊痘病毒引起的绵羊和山羊的高度传染性跨界病毒性疾病。本研究描述了间接ELISA的开发及其作为金标准血清中和试验（SNT）替代方法的血清学诊断潜力。使用痘苗病毒的同源物，即罗马尼亚费纳（RF）株绵羊痘病毒（SPPV）的ORF 117（A27L）基因，在原核表达系统中生产全长重组A27L（rA27L）蛋白（约22 kDa）。通过在蛋白质印迹分析中检测其与SPPV超免疫血清的特异性反应性，证实了纯化的rA27L的免疫原性潜力。开发并优化了基于rA27L的间接ELISA。与SNT相比，rA27L-ELISA检测对绵羊和山羊血清的诊断特异性分别为96%和98%，而敏感性分别为98%和97%。未发现与其他跨界疾病如羊口疮、口蹄疫、小反刍兽疫、出血性败血症和布鲁氏菌病有交叉反应。总共对508份血清样本进行了初步分析测试。其中，绵羊（n = 270）和山羊（n = 238）的血清阳性率分别为31.85%和47.47%。此外，为了确定所开发检测方法的准确性，从印度小反刍动物数量较多的邦，包括安得拉邦、特伦甘纳邦、卡纳塔克邦、西孟加拉邦和古吉拉特邦，共分析了1731份血清样本。绵羊和山羊的总体血清阳性率分别为24%和19.12%。在检查的绵羊和山羊群体中，雌性和1至2岁年龄组的动物显示出较高的山羊痘病毒抗体。本研究强调了rA27L蛋白作为一种安全的替代血清学诊断试剂的潜在用途，与SNT不同，可用于绵羊和山羊山羊痘病毒感染的血清监测和血清学监测。
