Abstract: Objective　By infecting Microtus fortis and BALB/c mice with Schistosoma japonicum, we compared the histopathological differences at different time points post-infection between the two species, aiming to provide direct research evidence for establishing standard pathological evaluation criteria for the resistance of Microtus fortis to schistosomiasis.Methods　Fifty 8-week-old Microtus fortis and fifty BALB/c mice were selected and infected with Schistosoma japonicum cercariae (500 per mouse) via abdominal skin penetration. Necropsy was performed at 0 d (negative control group), 1, 3, 7, 10, 14, 21, 28, 35, and 42 d after infection, with 5 replicates at each time point. HE staining was used to observe pathological changes in the skin, lungs, liver, spleen, and portal lymph node. Results Compared with BALB/c mice, Microtus fortis exhibited earlier onset of overall pathological lesions in various tissues and organs after Schistosoma infection, with more obvious inflammatory responses, and such lesions mostly showed a tendency of attenuation in the late stage of infection. Meanwhile, no obvious egg structures of the worm were detected in any tissues and organs of Microtus fortis, and only child worm bodies were visible in the alveolar cavities at 3 d post-infection and in the local hepatic parenchyma of the liver at 10 d post-infection.Conclusion　Compared with BALB/c mice, Microtus fortis has natural resistance to Schistosoma japonicum. Schistosoma development in the Microtus fortis is hindered during the juvenile stage and cannot develop into adults. This study further improved the pathological changes of various tissues and organs in the anti schistosomiasis model of the Microtus fortis, which is beneficial for promoting the research and application of this characteristic experimental animal in the field of anti schistosomiasis.

Key words: Microtus fortis, Schistosoma japonicum, experimental animal model, pathological evaluation

摘要： 目的　通过应用日本血吸虫感染东方田鼠和BALB/c小鼠,比较二者感染后不同时间点的组织病理学差异, 以期为建立标准的东方田鼠抗血吸虫病模型病理学评价标准提供直接研究证据。方法　选取8周龄东方田鼠、 BALB/c小鼠各50只,通过腹部皮肤贴皮感染日本血吸虫尾蚴(500条/鼠),分别于感染后0 d(阴性对照组),1、3、 7、10、14、21、28、35、42 d进行剖检,每个时间点设5个重复,通过HE染色观察皮肤、肺、肝、脾和肝门淋巴结的病变 情况。结果　与BALB/c小鼠相比,东方田鼠感染血吸虫后各组织脏器整体病变产生较早,并表现出更明显的炎性 反应,且感染后期病变多呈减轻的趋势。同时,东方田鼠各组织脏器内均未见明显虫卵结构,仅于感染后3 d肺泡 腔内和感染后10 d肝局部肝实质内可见童虫虫体。结论　与BALB/c小鼠相比,东方田鼠具有天然抗日本血吸虫 特性,血吸虫在东方田鼠体内发育受阻于童虫期,无法发育至成虫。本研究进一步完善了东方田鼠抗血吸虫病模 型中各组织脏器的病理学改变,有利于推动东方田鼠这一特色实验动物在抗血吸虫病领域内的研究和应用。

关键词: 东方田鼠, 日本血吸虫, 实验动物模型, 病理学评价