Evaluation of some chemotherapeutics as anti-cryptosporidial agents in immunocompromised mice / Mennat Elrahman Ahmed Fahmy ; Supervised Amany Ahmed Abelaal , Soad Ismail Hassan , Hanaa Omar Fadl

Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Parasitology

Cryptosporidium species are apicomplexan protozoan parasites that infect gastrointestinal tract of a wide variety of animals, including humans. Since the immune status of the host is crucial for determining susceptibility to Cryptosporidium infection as well as the outcome and severity of the disease, the current work aimed to study the effect of combination therapy in treating cryptosporidiosis plus exploring the modulating effects of infection and the treatment on the local adaptive immune response in two different experimental mice models of immune-alteration; the diabetic (type 1) model and dexamethasone-treated model.The results of this study showed that the combination of selenium supplementation with ivermectin or nitazoxanide improved the percentage of oocysts reduction compared to groups receiving therapeutic drugs alone. Moreover, the combination of ivermectin with nitazoxanide gave the best oocysts reduction rates with the lowest score of ileitis severity. Immunohistochemical studies recorded the ability of treatment, in the diabetic infected groups, to up-regulate the local ileal CD4 and CD8 T cells with re-inversion of the ratio towards CD4 which is essential for cure, indicating the good impact of treatment on the local immunity. On the other hand, in all dexamethasone-treated groups, CD4 T cells were down-regulated and could not be elevated enough even after treatment. This indicates the liability of the diabetic model to tolerate Cryptosporidium infection if properly treated

Issued also as CD