Abstract：
Visceral leishmaniasis (VL) is a fatal manifestation of an infection caused by intracellular protozoa of the Leishmania genus. In New World countries, VL is classified as a zoonotic disease with domestic dogs acting as its main reservoir. Asymptomatic dogs are as competent to transmit Leishmania to the vectors as symptomatic dogs, however current diagnostic tests are limited and present low sensitivity for this important group. The development of accurate tests is fundamental to the early diagnosis, treatment, and control of canine leishmaniasis. In this study, we investigated the use of a recombinant protein (dynamin-1-like protein, Dyn-1) from L. infantum, as a potential target antigen for leishmaniasis serodiagnosis in both symptomatic and asymptomatic dogs. The antigenic performance of the protein was evaluated by means of ELISA assays using sera from symptomatic (n = 25), asymptomatic (n = 34) and non-infected dogs (n = 36) using ELISA. In addition, sera from dogs experimentally infected with Trypanosoma cruzi (n = 49) and naturally infected with Babesia sp. (n = 8) were tested to evaluate possible cross-reactivity. A crude soluble antigen (CSA) of Leishmania was used as an antigen control and K39 and K26 were used as reference antigens because they are already widely used in commercial tests. rDyn-1-based assay showed the highest sensitivity (97%) compared to the antigens K39 (88%), K26 (86%) and crude extract (95%). The highest specificity among the tests was also obtained with the protein rDyn-1 (94%), compared with the other antigens K39 (81%), K26 (87%), and crude extract (77%). This study showed that the rDyn-1 ELISA assay was able to identify 100% of asymptomatic dogs, establishing its potential as a target for the diagnosis of canine leishmaniasis.
摘要：
内脏利什曼病（VL）是由利什曼原虫属的细胞内原生动物引起的感染的致命表现。在新世界国家,VL被归类为人畜共患疾病，家犬是其主要水库。无症状的狗与有症状的狗一样有能力将利什曼原虫传播给载体，然而，目前的诊断测试是有限的，对这一重要人群的敏感性较低。准确测试的发展是早期诊断的基础，治疗,和控制犬利什曼病。在这项研究中,我们研究了重组蛋白(dynamin-1-likeprotein,Dyn-1）来自L.婴儿，作为利什曼病血清诊断有症状和无症状犬的潜在靶抗原。通过使用来自症状（n=25）的血清的ELISA测定来评估蛋白质的抗原性能，使用ELISA的无症状（n=34）和未感染的狗（n=36）。此外,实验感染克氏锥虫（n=49）并自然感染巴贝虫的狗的血清。测试(n=8)以评估可能的交叉反应性。利什曼原虫的粗可溶性抗原（CSA）用作抗原对照，而K39和K26用作参考抗原，因为它们已经广泛用于商业测试。与抗原K39（88％）相比，基于rDyn-1的检测显示出最高的灵敏度（97％），K26(86%)和粗提物(95%)。rDyn-1蛋白（94％）也获得了测试中最高的特异性，与其他抗原K39（81%）相比，K26（87%），和粗提物(77%)。这项研究表明，rDyn-1ELISA测定法能够识别100％的无症状犬，确立其作为犬利什曼病诊断目标的潜力。
