Bomfim Maria Rosa Quaresma, Ko Albert, Koury Matilde Cota
Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 Belo Horizonte, MG, Brazil.
Vet Microbiol. 2005 Aug 10;109(1-2):89-94. doi: 10.1016/j.vetmic.2005.05.002.
The recombinant leptospiral protein LipL32 was evaluated for use in the diagnosis of bovine leptospirosis by enzyme-linked immunosorbent assay (rLipL32 IgG ELISA). The microscopic agglutination test (MAT) of 150 serum samples from cattle suspected of leptospirosis showed that 125 (83.3%) samples had positive reciprocal agglutination titres, which ranged from 100 to 1600. The highest titres were observed for the serovars Hardjoprajitno and Bratislava. In the rLipL32 IgG ELISA, 83.3% of the samples were positive. The sensitivity of IgG ELISA for 125 bovine sera, which had MAT titres of greater than or equal to 100, was 100%. ELISA showed a specificity of 100% with 58 bovine sera, which were negative at a 1:50 dilution in the MAT for Leptospira interrogans serovars. When analytical specificity of the IgG ELISA was evaluted using 60 bovine serum samples from animals showing serum antibodies to other pathogens that cause abortion in cattle, such as Babesia sp., Anaplasma sp. and Brucella sp. and no cross-reaction was observed. The recombinant LipL32 IgG ELISA can be an alternative to the MAT for diagnosis of leptospiral infection in cattle.
通过酶联免疫吸附试验（rLipL32 IgG ELISA）评估重组钩端螺旋体蛋白LipL32在牛钩端螺旋体病诊断中的应用。对150份疑似钩端螺旋体病牛血清样本进行显微镜凝集试验（MAT），结果显示125份（83.3%）样本的凝集效价呈阳性，范围为100至1600。其中，Hardjoprajitno和布拉迪斯拉发血清型的凝集效价最高。在rLipL32 IgG ELISA中，83.3%的样本呈阳性。对于MAT效价大于或等于100的125份牛血清，IgG ELISA的敏感性为100%。ELISA对58份牛血清的特异性为100%，这些血清在问号钩端螺旋体血清型的MAT中以1:50稀释时呈阴性。当使用60份来自感染其他可导致牛流产病原体（如巴贝斯虫、无形体和布鲁氏菌）的动物的牛血清样本评估IgG ELISA的分析特异性时，未观察到交叉反应。重组LipL32 IgG ELISA可作为MAT的替代方法用于诊断牛钩端螺旋体感染。
