BACKGROUND Haemonchus contortus (H. contortus) is one of the most important parasites that cause huge economic losses to small ruminant industry worldwide. Effective prognosis and treatment depend upon the early diagnosis of H. contortus infection. To date, no widely-approved methods for the identification of prepatent H. contortus infection are available to identify prepatent H. contortus infection properly. The aim of this study was to evaluate the diagnostic potential of recombinant cold shock H. contortus protein (rHc-CS) during early and late infections of H. contortus in goat. RESULTS Purified rHc-CS exhibited a clear band, with a molecular weight about 38 kDa. H. contortus eggs were not detected by fecal egg count technique from feces collected at 0 to 14 days post infection (D.P.I). However, eggs were detected at 21, 28 and 35 D.P.I. Hence, results of immunoblotting assay showed specific anti rHc-CS antibody detection in all goat sera collected at early stage (14 D.P.I) and late stage (21-103 D.P.I) of H. contortus infection. Furthermore, no cross reactivity was observed against Trichinella spiralis, Fasciola hepatica and Toxoplasma gondii or uninfected goats. Among several evaluated rHc-CS indirect-ELISA format variables, favorable antigen coating concentration was found 0.28 μg/well at 37 °C 1 h and overnight at 4 °C. Moreover, optimum dilution ratio of serum and rabbit anti-goat IgG was recorded as 1:100 and 1:4000, respectively. The best blocking buffer was 5% Bovine Serum Albumin (BSA) while the best time for blocking, serum incubation and TMB reaction were recorded as 60, 120 and 10 min, respectively. The cut-off value for positive and negative interpretation was determined as 0.352 (OD450). The diagnostic specificity and sensitivity of the rHc-CS, both were recorded as 100%. CONCLUSION These results validated that rHc-CS is a potential immunodiagnostic antigen to detect the specific antibodies during early and late H. contortus infections in goat.

中文翻译：

---

含有蛋白的重组冷休克结构域是检测山羊捻转血矛线虫早期和晚期感染期间特异性抗体的潜在抗原。


背景技术捻转血矛线虫（H. contortus）是给全世界小型反刍动物产业造成巨大经济损失的最重要的寄生虫之一。有效的预后和治疗取决于捻转螺旋体感染的早期诊断。迄今为止，还没有广泛认可的鉴定显性扭伤螺杆菌感染的方法来正确识别显性扭伤螺杆菌感染。本研究的目的是评估重组冷休克扭伤扭伤蛋白 (rHc-CS) 在山羊扭伤扭伤早期和晚期感染期间的诊断潜力。结果纯化的rHc-CS条带清晰，分子量约为38 kDa。通过粪便虫卵计数技术，在感染后 0 至 14 天 (DPI) 收集的粪便中未检测到捻转扭伤虫卵。然而，在 21、28 和 35 DPI 时检测到卵。因此，免疫印迹测定结果显示，在幽门螺杆菌早期 (14 DPI) 和晚期 (21-103 DPI) 收集的所有山羊血清中均检测到特异性抗 rHc-CS 抗体。扭转感染。此外，未观察到针对旋毛虫、肝片形吸虫和弓形虫或未感染山羊的交叉反应。在几个评估的 rHc-CS 间接 ELISA 格式变量中，发现有利的抗原包被浓度为 0.28 μg/孔，37 °C 1 小时，4 °C 过夜。此外，血清和兔抗羊IgG的最佳稀释比分别为1:100和1:4000。最佳封闭缓冲液为5%牛血清白蛋白(BSA)，最佳封闭时间、血清孵育时间和TMB反应时间分别为60、120和10分钟。阳性和阴性解释的截止值确定为 0.352 (OD450)。 rHc-CS 的诊断特异性和敏感性均为 100%。结论 这些结果证实 rHc-CS 是一种潜在的免疫诊断抗原，可用于检测山羊早期和晚期捻转螺旋体感染期间的特异性抗体。