Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, 6517658978, Iran.
Department of Clinical Sciences, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, 6517658978, Iran.
Parasitol Res. 2023 Mar;122(3):847-852. doi: 10.1007/s00436-023-07783-w. Epub 2023 Jan 19.
The protozoan parasite Neospora caninum infects carnivores as definitive and a wide range of mammals as intermediate hosts. This parasite is regarded as an important cause of abortion in cattle worldwide, causing significant economic losses. Although there is serological evidence of infection in Old World camelids, the significance of N. caninum in these animal species is still poorly understood. The aim of this study was to use molecular and histological methods to detect N. caninum in the blood and tissues of 100 slaughtered one-humped camels (Camelus dromedarius) in Iran. For this, genomic DNA was extracted from blood, brain, portal lymph node and liver of the camels, and nested-PCR assay followed by sequencing were performed. Besides, paraffin-embedded tissue sections were stained with hematoxylin and eosin (H&E) and studied microscopically. In addition, immunohistochemical staining for N. caninum was attempted on brain samples with positive PCR results. All animals were tested for antibodies against N. caninum and Toxoplasma gondii by whole tachyzoite-agglutination tests. N. caninum DNA was detected in blood, brain, and portal lymph node, but not in the liver of two (2%) camels. Histopathological examination revealed cysts resembling N. caninum in brain samples of one of these camels; however, immunohistochemical staining for N. caninum and T. gondii did not allow a morphological identification. IgG antibodies to N. caninum and T. gondii were detected in 36% and 35% of the camels, respectively. This study provides the first insight into direct detection of N. caninum in C. dromedarius in Iran. Further molecular studies on aborted fetuses, stillborn animals and cases of perinatal mortality are needed to understand the possible involvement of N. caninum in cases of reproductive failure. As the definitive hosts of N. caninum are domestic and wild canids, producers should be advised to monitor and limit exposure of their camelids to these species and their feces.
刚地弓形虫是一种原生动物寄生虫，以肉食动物为终末宿主，以广泛的哺乳动物为中间宿主。这种寄生虫被认为是全世界牛流产的重要原因，造成了重大的经济损失。尽管在旧大陆骆驼中有感染刚地弓形虫的血清学证据，但这种寄生虫在这些动物物种中的重要性仍知之甚少。本研究旨在使用分子和组织学方法检测伊朗 100 只单峰驼（Camelus dromedarius）血液和组织中的刚地弓形虫。为此，从骆驼的血液、大脑、门脉淋巴结和肝脏中提取基因组 DNA，并进行巢式 PCR 检测和测序。此外，还对石蜡包埋的组织切片进行了苏木精和伊红（H&E）染色，并进行了显微镜检查。此外，还尝试对 PCR 结果为阳性的脑组织进行刚地弓形虫免疫组织化学染色。所有动物均通过全速殖子凝集试验检测抗刚地弓形虫和弓形虫的抗体。在 2%的 2 只骆驼的血液、大脑和门脉淋巴结中检测到刚地弓形虫 DNA，但在肝脏中未检测到。组织病理学检查显示，在其中一只骆驼的脑组织样本中发现了类似于刚地弓形虫的囊肿；然而，刚地弓形虫和弓形虫的免疫组织化学染色不允许进行形态学鉴定。36%和 35%的骆驼分别检测到抗刚地弓形虫和弓形虫的 IgG 抗体。本研究首次提供了在伊朗的 C. dromedarius 中直接检测刚地弓形虫的见解。需要进一步进行分子研究，以了解流产胎儿、死胎和围产期死亡病例中是否存在刚地弓形虫，以了解其在生殖失败病例中的可能参与。由于刚地弓形虫的终末宿主是家养和野生犬科动物，建议生产者监测并限制其骆驼接触这些物种及其粪便。
