关键词: 东方田鼠, 日本血吸虫, 实验动物模型, 病理学评价

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