Animal Health Division, Central Institute for Research on Goats, Makhdoom, 281 122 PO-Farah, District-Mathura (UP) India.
Indian J Microbiol. 2007 Sep;47(3):251-8. doi: 10.1007/s12088-007-0046-2. Epub 2007 Oct 4.
Country lacks sensitive and indigenous diagnostic kits for the screening of goats and sheep against Johne's disease. Therefore an indigenous ELISA kit was developed using protoplasmic antigen from native Mycobacterium avium subspecies paratuberculosis 'Bison Type' strain of goat origin (Kit 1). In the present study, kit 1 and two commercial kits (kit 2 and 3) were evaluated with respect to 'Gold Standard' fecal culture in 71 animals (55 goats and 16 sheep). Kit 1 using indigenous antigen (protoplasmic antigen) was sensitive at very low concentration (0.1 μgm / well) as compared to purified commercial protoplasmic antigen (4 μgm / well) used in kit 2, in the Type 1 reactors (strong positive as positive). Screening of 71 animals by fecal culture detected 38.0% animals (goats-40.0%, sheep-31.2%) as positive (clinical shedders of bacilli) from these farm animals. Of the farm animals located at Central Institute for Research on Goats, herds of goat were endemic whereas, sheep flocks were comparatively resistant to Johne's disease. The 29.5 and 61.9, 15.4 and 57.7 and 4.2 and 14.0% animals (goats and sheep) were in the category of sero-reactors type 1 and 2 of the ELISA kits 1, 2 and 3, respectively. In the type 1 sero-reactors, sensitivity and specificity of kit 1, 2 and 3 was 53.7 and 86.0, 17.8 and 86.0 and 3.5 and 94.7%, respectively. Indigenous ELISA test (kit 1) was significantly superior for the screening of goatherds and sheep flocks against JD as compared to commercial ELISA kits (Kit 2 and 3). In comparison to kit 2 and 3, kit 1 had highest sensitivity, comparable specificity and substantial to nearly perfect proportional agreement (Kappa Scores) with respect to 'Gold standard' fecal culture in goats and sheep. Disease being endemic in herds and flocks screened using ELISA kits, Type I sero-rectors had better correlation with fecal culture in comparison to Type II sero-reactors therefore, used for estimation of sero-prevalence. Newly developed Indigenous ELISA kit was simple, inexpensive, sensitive and reliable for screening of goats and sheep population against Johne's disease. The study reports high prevalence of Johne's disease in farm goatherds and sheep flocks, using sensitive tests (fecal culture and ELISA kit). Results of Type 1 reaction in kit 1 were optimally correlated with culture and were good for estimating the sero-prevalence. For controlling Johne's disease in endemic herds initial removal of the animals in strong positive category (Tyep 1 reactors), may help to remove heavy shedders.
该国缺乏用于筛查山羊和绵羊约翰氏病的敏感和本土诊断试剂盒。因此，使用源自本地牛分枝杆菌亚种副结核分枝杆菌“野牛型”山羊来源的原生质抗原开发了一种本土 ELISA 试剂盒（试剂盒 1）。在本研究中，使用“金标准”粪便培养方法评估了试剂盒 1 和两种商业试剂盒（试剂盒 2 和 3）在 71 只动物（55 只山羊和 16 只绵羊）中的应用。试剂盒 1 使用本土抗原（原生质抗原），与试剂盒 2 中使用的纯化商业原生质抗原（4μg /孔）相比，在 1 型反应者（强阳性如阳性）中具有较低的敏感性（0.1μg /孔）。通过粪便培养筛查 71 只动物，从这些农场动物中发现 38.0%的动物（山羊-40.0%，绵羊-31.2%）为阳性（杆菌的临床排放者）。位于中央山羊研究所的农场动物中，山羊群是地方性的，而绵羊群对约翰氏病的抵抗力相对较强。在 ELISA 试剂盒 1、2 和 3 的 1 型和 2 型血清反应者中，分别有 29.5%和 61.9%、15.4%和 57.7%和 4.2%和 14.0%的动物（山羊和绵羊）。在 1 型血清反应者中，试剂盒 1、2 和 3 的灵敏度和特异性分别为 53.7%和 86.0%、17.8%和 86.0%和 3.5%和 94.7%。与商业 ELISA 试剂盒（试剂盒 2 和 3）相比，本土 ELISA 检测（试剂盒 1）在筛查山羊和绵羊群的 JD 方面具有显著优势。与试剂盒 2 和 3 相比，试剂盒 1 具有更高的灵敏度、相当的特异性和与“金标准”粪便培养相比具有实质性到近乎完美的比例一致性（Kappa 评分）在山羊和绵羊中。在使用 ELISA 试剂盒进行筛查的畜群和羊群中，1 型血清反应者与粪便培养的相关性优于 2 型血清反应者，因此用于估计血清流行率。新开发的本土 ELISA 试剂盒简单、廉价、敏感且可靠，可用于筛查山羊和绵羊群体的约翰氏病。该研究报告了在使用敏感检测方法（粪便培养和 ELISA 试剂盒）时，农场山羊和绵羊群中约翰氏病的高流行率。试剂盒 1 中 1 型反应的结果与培养结果最佳相关，非常适合估计血清流行率。对于控制地方性畜群中的约翰氏病，最初去除强阳性（1 型反应者）类别的动物可能有助于去除大量的排放者。
