Serodiagnosis of bovine trypanosomosis caused by non-tsetse transmitted Trypanosoma (Duttonella) vivax parasites using the soluble form of a Trypanozoon variant surface glycoprotein antigen
Serodiagnosis of bovine trypanosomosis caused by non-tsetse transmitted Trypanosoma (Duttonella) vivax parasites using the soluble form of a Trypanozoon variant surface glycoprotein antigen
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DOI：
10.1016/j.vetpar.2016.01.007
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发表时间：
2016-03-15
影响因子：
2.6
通讯作者：
Bubis, Jose
中科院分区：
文献类型：
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作者：
Uzcanga, Graciela L.;Perez-Rojas, Yenis;Bubis, Jose
先前的研究表明，从委内瑞拉马锥虫TeAp-N/D1分离株中纯化的64 kDa抗原（p64）对应于其主要变体表面糖蛋白（VSG）的可溶性形式，并与间日锥虫（Duttonella）表现出交叉反应性。用T.用间接酶联免疫吸附试验（ELISA）检测动物血清中抗p64抗体和特异性抗p64 IgG和IgM抗体。用350份健康牛和锥虫病牛血清检测了p64对锥虫病的诊断价值。间日疟原虫感染的奶牛生活在锥虫病流行和地方病稳定地区，和48血清锥虫病爆发期间获得。血清学检测结果表明，约70-80%的感染血清含有抗p64抗体，这是基于T. Equiperdum澄清抗原级分用作参比试验。在缺乏金标准的情况下，贝叶斯分析多重检测估计的灵敏度和特异性分别为71.6%和98.8%，间接ELISA使用p64作为抗原。当使用p64 ELISA试验时，用贝叶斯方法估计牛锥虫病感染的表观患病率为37.7%。采用血液从急性感染的奶牛，对p64的间接ELISA反应进行了对比与微量红细胞压积离心法和聚合酶链反应（PCR）分析，使用特异性引物针对18 S核糖体基因的内部转录间隔区1区域的种间长度变异。p64用于检测急性感染牛中抗锥虫抗体的效率也通过比较其与印度尼西亚伊氏锥虫Rode锥虫抗原型（RoTat）1.2 VSG的反应而在血清学上得到证实，该VSG具有高特异性和灵敏度。正如预期的那样，PCR是检测寄生虫和诊断牛锥虫病的最佳方法;然而，当比较使用p64和RoTat 1.2 VSG的血清学试验时，获得了相当程度的一致性（Cohen's kappa=0.667）。此外，使用p64共价偶联到羧基修饰的乳胶微粒，这是在这里被证明是适合于快速定性诊断牛锥虫病的凝集试验设计。(C)© 2016 Elsevier B. V.版权所有。
Previous studies have shown that a 64-kDa antigen (p64) that was purified from the Venezuelan TeAp-N/D1 isolate of Trypanosoma (Trypanozoon) equiperdum corresponds to the soluble form of its predominant variant surface glycoprotein (VSG), and exhibited cross-reactivity with Trypanosoma (Duttonella) vivax. The course of experimental acute infections of bovines with T. vivax were followed by measuring whole anti-p64 antibodies and specific anti-p64 IgG and IgM antibodies in animal sera by indirect enzyme-linked immunosorbent assay (ELISA). The value of p64 to diagnose bovine trypanosomosis was also examined using 350 sera from healthy and T. vivax-infected cows living in a trypanosomosisendemic and enzootic stable area, and 48 sera obtained during a trypanosomosis outbreak. Serological assays showed that similar to 70-80% of the infected sera contained anti-p64 antibodies, based on the comparative immunodetection of the T. equiperdum clarified antigenic fraction used as a reference test. In the absence of a gold standard, Bayesian analysis for multiple testing estimated a sensitivity and specificity of 71.6% and 98.8%, respectively, for the indirect ELISA using p64 as antigen. An apparent prevalence of 37.7% for bovine trypanosomosis infection was also estimated with a Bayesian approach when the p64 ELISA test was used. Employing blood from acute infected cows, the indirect ELISA response against p64 was contrasted with the microhematocrit centrifuge method and analyses by polymerase chain reaction (PCR) using specific primers targeting the inter-specific length variation of the internal transcribed spacer 1 region of the 18S ribosomal gene. The efficiency of p64 for the detection of anti-trypanosome antibodies in acute infected bovines was also corroborated serologically by comparing its response to that of the Indonesian Trypanosoma evansi Rode Trypanozoon antigen type (RoTat) 1.2 VSG, which possesses high specificity and sensitivity. As expected, PCR was the best method to detect parasites and diagnose bovine trypanosomosis; however, a substantial level of concordance (Cohen's kappa=0.667) was obtained when serological tests using p64 and RoTat 1.2 VSG were compared. Additionally, an agglutination assay was designed using p64 covalently coupled to carboxylate-modified latex microparticles, which was proven here to be suitable for a fast qualitative diagnosis of bovine trypanosomosis. (C) 2016 Elsevier B.V. All rights reserved.