Potential role of Cryptosporidium infection in triggering intestinal neoplasia in a mouse model / Mennat El-Rahman Ahmed Fahmy ; Supervised Mousa Abdelgawad Mousa Ismail , Maisa Ahmad Shalaby , Hebat-Allah Salah Ahmad Yousof

Thesis (M.Sc.) - Cairo University - Faculty of Medicine - Department of Parasitology

Cryptosporidium species are apicomplexan protozoans that are found worldwide. These parasites constitute a large risk to human and animal health. They cause self-limited diarrhea in immunocompetent hosts and a life-threatening disease in immunocompromised hosts. Interestingly, they have been related to digestive carcinogenesis in humans.We aimed to study the histopathological and immunohistochemical changes in ileocecal region induced by chronic irritation with different inoculum sizes of Cryptosporidium (high dose and low dose of oocysts) in immunosuppressed mice.To further characterize this Cryptosporidium -induced cell transformation, mice were euthanatized sequentially at the 25th, 35th and 46th days post 1st infection for histopathological examination and to detect alteration in the expression of Ý-catenin and p53 as markers of cellular proliferation. Histopathological examination of sections from the ileocecal region of sacrificed mice showed mild to severe villous atrophy and inflammatory exudation in colonic mucosa, mice receiving high inoculum dose experienced more severe histopathological changes.We also recorded alteration in the expression of Ý-catenin in the form of progressive increase of the cytoplasmic labeling of Ý-catenin after the 25th day post-infection, without loss of Ý-catenin membrane labeling in groups infected once with Cryptosporidium oocysts, but in groups repeatedly infected with Cryptosporidium oocysts there was loss of Ý-catenin membrane labeling and progressive increase of the cytoplasmic labeling of Ý-catenin after the 25th day post first infection, without nuclear expression of Ý-catenin or nuclear expression of p53 in all infected groups

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