Budovsky A, Prinsloo I, El-On J
Department of Microbiology and Immunology, Ben-Gurion University of the Negev, Israel.
Parasitol Int. 2006 Dec;55(4):237-42. doi: 10.1016/j.parint.2006.06.001. Epub 2006 Jul 20.
Trypanosoma lewisi is an obligatory, flagellated parasite of the rat. Despite the fact that naturally the rats overcome the disease, a lethal infection can be induced by the administration of an immunosuppressive agent, i.e. cyclophosphamide (Cy). In the Cy treated infected rats (CyI) the severity of the trypanosome infection was demonstrated in the internal organs, in the following order: lungs>liver>heart>spleen>kidney. The parasites were not detected in the brain. The accumulation of the parasites in the lungs led to the development of hemorrhagic inflammatory foci. The rupture of blood vessels was accompanied by lymphocyte infiltrations into the damaged tissues and multiple foci of edema around the blood vessels. In most cases the lungs were dark brown in color due to intra-alveolar hemorrhages. The spleen of the CyI rats showed general deformation of the tissue's architecture, migration of macrophages and cell depletion due to the Cy action. The liver showed inflammatory hemorrhagic foci associated with massive destruction of the parenchyma. In spite of the heavy parasitemia (>50%) developed in the CyI rats the brain remained free of parasites, which might explain the non-virulent character of this parasite compared to the African trypanosomes.
路氏锥虫是大鼠的一种专性、具鞭毛的寄生虫。尽管大鼠通常能战胜这种疾病，但通过给予免疫抑制剂（即环磷酰胺（Cy））可诱发致死性感染。在经Cy处理的感染大鼠（CyI）中，锥虫感染在各内脏器官中的严重程度依次为：肺>肝>心>脾>肾。在脑中未检测到寄生虫。寄生虫在肺中的积聚导致出血性炎症病灶的形成。血管破裂伴有淋巴细胞浸润到受损组织以及血管周围多处水肿灶。在大多数情况下，由于肺泡内出血，肺呈深褐色。CyI大鼠的脾脏显示出组织结构的普遍变形、巨噬细胞迁移以及由于Cy的作用导致的细胞减少。肝脏显示出与实质大量破坏相关的炎症出血灶。尽管CyI大鼠出现了严重的寄生虫血症（>50%），但脑内仍无寄生虫，这可能解释了与非洲锥虫相比这种寄生虫的无毒特性。
