The objective of the study was to develop a bio-safe synthetic peptide ELISA for the detection of antibodies against the infectious bronchitis virus (IBV) using a novel multiple antigenic peptide approach (MAP). After initial ELISA optimization, diagnostic sensitivity (DSn) and specificity (DSp) for the linear peptides were determined using receiver operator curve (ROC) analysis. The peptide IBVP1 showed 90.44% DSn and 88.64% DSp at ROC cut off 22.8% while IBVP2 showed 88.24% DSn and 85.23% DSp at ROC cut off 23.05%. The multimerization of linear peptides to MAP design resulted in the improvement of the diagnostic efficiency up to 94.85% DSn and 92.05% DSp for IBVM1 with 19.95% cut off. A similar improvement in the performance was also observed with 92.65% DSn and 90.91% DSp for IBVM2 at 20.72% cut off. All the peptides were tested for diagnostic specificity and did not show the cross-reactivity with Newcastle disease virus and infectious bursal disease virus positive serum samples. In addition, repeatability testing for all linear and multimeric peptide showed that the coefficient of variation for intra-assay was within the expected limits, ranging from 2.4 to 10.4% and inter-assay coefficient of variation was ranging from 5.56 to 14.3%. In a nutshell, the present study used predicted B cell epitope, the synthetic peptide in linear and multimeric design for IBV antibody detection. The study also highlights peptide antigen with modified scaffold design could be a safe alternative to whole virion-based ELISA for IBV antibody detection.

该研究的目的是开发一种生物安全的合成肽 ELISA，用于使用新型多抗原肽方法 (MAP) 检测针对传染性支气管炎病毒 (IBV) 的抗体。在初始 ELISA 优化后，线性肽的诊断灵敏度 (DSn) 和特异性 (DSp) 使用接受者操作曲线 (ROC) 分析确定。肽 IBVP1 在 ROC 截止值为 22.8% 时显示 90.44% DSn 和 88.64% DSp，而 IBVP2 在 ROC 截止值为 23.05% 时显示 88.24% DSn 和 85.23% DSp。线性肽与 MAP 设计的多聚化导致 IBVM1 的诊断效率提高至 94.85% DSn 和 92.05% DSp，截断率为 19.95%。IBVM2 的 92.65% DSn 和 90.91% Dsp 在 20.72% 截止时也观察到了类似的性能改进。测试所有肽的诊断特异性并且未显示与新城疫病毒和传染性法氏囊病病毒阳性血清样品的交叉反应性。此外，所有线性和多聚体肽的重复性测试表明，批内变异系数在预期范围内，范围为 2.4 至 10.4%，批间变异系数范围为 5.56 至 14.3%。简而言之，本研究使用预测的 B 细胞表位，即线性和多聚体设计的合成肽，用于 IBV 抗体检测。该研究还强调，具有改良支架设计的肽抗原可能是基于全病毒体的 ELISA 的安全替代方案，用于 IBV 抗体检测。