Abstract: In order to study the pathogenesis of rotavirus (RV), Balb/c neonatal mices were developed for diarrhea model using rotavirus strain SA11. These data provide theoretical and experimental basis for vaccine protection evaluation. The 7-day-old Balb/c mices were intragastrically administrated with RV SA11 strain in different doses. The diarrhea status of these mice were observed at different time points. These mices were euthanized and dissected. Heart, liver, spleen, lung, small intestine and kidney and other tissues of euthanized mices were collected and detected by immunofluorescence for Rotavirus distribution. The collected tissues were fixed in formalin and used in HE staining and IHC staining for the detection of pathological changes of jejunum and the apoptosis of the cells. Obvious diarrhea symptoms were observed at 24 h post inoculation with Rotavirus strain SA11. Pathological anatomy results showed that the intestines of these model mices were congested and flattened after 72 h infection. Compared to the controls,the results of intestine HE staining showed that the pathological changes in model mice were obvious, including vacuolar degeneration, edema and congestion of intestinal wall, integrity destruction of enteric epithelium and cell apoptosis, after intragastrically administered with SA11 strain. Rotavirus distribution in intestine and kidneys was also detected by immunofluorescence assay. In this study, the rotavirus diarrhea models of Balb/c neonatal mice were developed successfully with RV SA11 strain. In addition to small intestine distribution,we found that Rotavirus distribution could also be detected in kidney of Balb/c neonatal mice after infection.

Key words: rotavirus, animal model, Balb/c neonatal mice, pathogenesis