Parasitology Lab, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India.
Parasitology Lab, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India.
Res Vet Sci. 2022 Dec 20;152:604-609. doi: 10.1016/j.rvsc.2022.09.016. Epub 2022 Sep 22.
Surra caused by an extracellular hemoflagellate, Trypanosoma evansi, leads to severe economic loss to livestock productivity in India. Among the various mammalian pathogenic trypanosomes, T. evansi has the widest host range.Usually, species specific conjugates are used in conventional indirect immunosorbent assay (ELISA) for diagnosis of T. evansi infection in different animal species. The aim of the study was to explore the use of non-species specific conjugates viz., protein A, G and chimeric protein A/G instead of species specific conjugates for development of indirect ELISAs. These assays were used for detection of antibodies against T. evansi infection in multiple animal species viz., equine, cattle, buffalo, dog, pig and camel. The functional affinities of serum immunoglobulins of six different animal species with different conjugates were determined by estimation of relative avidity index (RAI). The species specific conjugate based whole cell lysate- T. evansi antigen ELISA was considered as reference assay for comparison of sensitivity and specificity of non-species specific conjugates based ELISAs optimized in the present study. Data showed that serodiagnosis of T. evansi can be carried out by using chimeric protein A/G conjugate in multiple hosts viz., equine, buffalo, camel, pig and dog; protein G conjugate in equine and buffalo and protein A conjugate in camel, pig and dog. The relative diagnostic sensitivity and specificity for chimeric protein A/G conjugate varied from 60 to 100% and 79-100%, respectively for different livestock species. This approach might be helpful in monitoring and surveillance of T. evansi infection in multiple hosts in particular when host specific secondary antibody conjugates are not available. Investigations should be made in wild animals and other warm-blooded vertebrates to validate this hypothesis.
苏拉病由一种细胞外血鞭毛原生动物，即伊氏锥虫引起，导致印度牲畜生产力遭受严重经济损失。在各种哺乳动物致病性锥虫中，伊氏锥虫宿主范围最广。通常，在不同动物物种中，针对伊氏锥虫感染的常规间接免疫吸附测定（ELISA）使用物种特异性缀合物。本研究旨在探索使用非物种特异性缀合物（即蛋白 A、G 和嵌合蛋白 A/G）代替物种特异性缀合物来开发间接 ELISA。这些检测方法用于检测多种动物物种（马、牛、水牛、狗、猪和骆驼）中针对伊氏锥虫感染的抗体。通过估计相对亲和力指数（RAI），确定了六种不同动物物种的血清免疫球蛋白与不同缀合物的功能亲和力。基于物种特异性缀合物的全细胞裂解物-伊氏锥虫抗原 ELISA 被认为是参考测定方法，用于比较本研究优化的非物种特异性缀合物 ELISA 的敏感性和特异性。数据表明，使用嵌合蛋白 A/G 缀合物可以在多种宿主（马、水牛、骆驼、猪和狗）中进行伊氏锥虫的血清学诊断；在马和水牛中使用蛋白 G 缀合物，在骆驼、猪和狗中使用蛋白 A 缀合物。嵌合蛋白 A/G 缀合物的相对诊断敏感性和特异性在不同的牲畜物种中分别为 60-100%和 79-100%。当没有宿主特异性二抗缀合物时，这种方法可能有助于监测和调查多种宿主中的伊氏锥虫感染。应在野生动物和其他温血脊椎动物中进行调查，以验证这一假设。
