Studies On The Animal Models Of Toxoplasma Gondii Chronic Infection

Toxoplasma gondii is an intracellular protozoan parasite and the etiological agent of toxoplasmosis. Susceptivity is varied in different animal, as well as the symptom and sequel of the infection.A suitable animal model is a key point in researches.It has great value to established chronic infected animal model because toxoplasmosis is generally chronic,and such animal model is important in research about diagnosis,vaccine and therapy of toxoplasmosisRH strain of Toxoplasma gondii is virulent.Mice is susceptive to it, and usually die after infected with RH strain tachyzoite,by intraperitoneally injecting or subcutaneous injecting. However,according to report,part of mice can be survived from Toxoplasma gondii tachyzoite infection when infected by oral way.Like human beings,rats is not susceptive to Toxoplasma gondii,it is generally asymptomatic after infected with Toxoplasma gondii.So,rats' infection is more similar to human's toxoplasmosis.It has more value in researching diagnosis,pathogenic biology,vaccine of toxoplasmosis.The strong resistance of rats can be changed by using immunosuppressed drug or irradiation.There are oxygen-dependent mechanism and oxygen-independent mechanism in host to control replication of killing Toxoplasma gondii. NO has been regarded as essential role in host against the parasite. Can the sera NO concentration of rats be changed after injected with dexamethasone or irradiated with X ray? Will the resistance to Toxoplasma gondi be changed or...