Evaluation of systemic tissue involvement in mice following intraperitoneal inoculation of Toxoplasma gondii RH Ankara strain

Abstract

Objective: This study aimed to pathologically evaluate systemic tissue involvement in acute toxoplasmosis in mice inoculated with Toxoplasma gondii RH Ankara strain. Method: Forty-two Mus musculus albino mice were divided into four groups with the control group receiving no inoculation, the group consisting of mice that were not sacrificed after intraperitoneal inoculation and the groups consisting of mice euthanasia were performed on day runner up or day fourth following intraperitoneal inoculation. A 48-50-hour intraperitoneal passage of T. gondii RH Ankara strain in mice was used for inoculation and each mouse received 5×104 tachyzoites. The mice sacrificed by euthanasia were macroscopically examined and then collected tissue samples fixed in 10% formalin. The preparations set by from the tissues blocked in paraffin were stained with hematoxylin-eosin and histopathological examination was performed. Results: Necrosis in the serosa of the intestine and parenchyma of the liver, spleen, kidneys, pancreases and omentum and many free groups of tachyzoites were observed. Tachyzoites were identified in alveolar capillary lumens in the lungs. No pathological finding was observed in the cerebrum and cerebellum but few tachyzoites. It was observed that tissue necrosis and the density of Toxoplasma gondii tachyzoites were directly proportional to the duration of post inoculation. All infected mice that received no intervention died on day sixth. In this study in mice, it was found that T. gondii RH Ankara strain induced the same pathological findings as the RH strain belonging to the virulent Type I group. Conclusion: Mice inoculation can be used for diagnosis and this model may also be used in studies investigating vaccination, drugs and pathogenesis.