The present study evaluated the comparative serodiagnostic efficacy of recombinant listeriolysin-O (rLLO) and synthetic LLO- 2 peptide-based indirect ELISA vis-à-vis cultural isolation using samples (n = 1326; blood, sera, vaginal swabs, and rectal swabs) collected from caprines (n = 350) and ovines (n = 50) having reproductive and/or nervous system disorders and/or healthy animals. On screening the test sera by rLLO- based ELISA, the antibodies against LLO (ALLO) were observed in 17.71% of the caprines and 2% of the ovines, respectively, while synthetic LLO-2- based ELISA revealed ALLO in 6.86% of caprines and not in ovines. Moreover, the adsorption of positive test sera with streptolysin-O (SLO) resulted in a significant reduction (7.43%; p < 0.05) in the seropositivity with rLLO- based ELISA, whereas LLO-2- based ELISA revealed marginal reduction (4.29%; p > 0.05) in the seropositivity. Overall, the seropositivity with LLO-2 synthetic peptide revealed comparatively less cross-reactivity in comparison to rLLO. The cultural isolation yielded five pathogenic L. monocytogenes isolates and three non-pathogenic Listeria spp. from caprine samples; however, Listeria spp. could not be recovered from any of the ovine samples. Further, on comparing seropositivity with the isolation study results, it was found that two out of the five animals from which pathogenic L. monocytogenes isolated were also found seropositive in both the ELISAs even after adsorption with SLO. Interestingly, rLLO- based ELISA detected antibodies against unadsorbed caprine sera even in those samples from which non-pathogenic Listeria spp. were isolated, whereas antibodies were not detected in LLO-2 peptide-based ELISA. In conclusion, it could be inferred that the synthetic LLO-2 peptide serves as a non- cross-reactive, ideal diagnostic antigen in serodiagnosis of capro-ovine listeriosis.

本研究使用样本（n  = 1326；血液、血清、阴道拭子和直肠拭子）评估了重组李斯特菌溶血素-O (rLLO) 和基于合成 LLO-2 肽的间接 ELISA 相对于培养分离的血清诊断功效的比较) 从 具有生殖和/或神经系统疾病和/或健康动物的山羊 ( n  = 350) 和绵羊 ( n = 50 ) 收集。通过基于 rLLO 的 ELISA 筛选测试血清时，分别在 17.71% 的山羊和 2% 的绵羊中观察到了针对 LLO (ALLO) 的抗体，而基于合成 LLO-2 的 ELISA 在 6.86% 的山羊中观察到了 ALLO而不是在绵羊。此外，链球菌溶血素-O (SLO) 对阳性测试血清的吸附导致显着降低 (7.43%; p < 0.05) 基于 rLLO 的 ELISA 的血清阳性，而基于 LLO-2 的 ELISA 显示 血清阳性的边缘减少 (4.29%; p > 0.05)。总体而言，与 rLLO 相比，LLO-2 合成肽的血清阳性显示交叉反应性相对较低。培养分离产生了五个致病性单核细胞增生李斯特菌分离株和三个非致病性李斯特菌。来自山羊样本；然而，李斯特菌属。无法从任何绵羊样本中回收。此外，在比较血清阳性与分离研究结果时，发现五只动物中有两只携带致病性单核细胞增生李斯特菌即使在用 SLO 吸附后，在两种 ELISA 中也发现分离的大肠杆菌。有趣的是，基于 rLLO 的 ELISA 检测到针对未吸附山羊血清的抗体，即使在那些非致病性李斯特菌属的样本中也是如此。被分离，而在基于 LLO-2 肽的 ELISA 中未检测到抗体。总之，可以推断合成的 LLO-2 肽在山羊李斯特菌病的血清学诊断中用作非交叉反应的理想诊断抗原。