Experimental congenital toxoplasmosis in Wistar and Holtzman rats

Abstract

Congenital toxoplasmosis was evaluated in Wistar and Holtzman rats using two strains of Toxoplasma gondii isolated in Brazil. Pregnant rats were inoculated by subcutaneous or intraperitoneal routes with 106 or 8 × 106 tachyzoites of N strain (virulent for mice) and by subcutaneous or oral routes with 102 or 1.2 × 103 cysts of P strain (avirulent for mice). The tissues of rat pups born from these rats were bioassayed for T. gondii infection. T. gondii was not observed in the pups born from rats inoculated with N strain. In the animals inoculated with P strain, congenital toxoplasmosis occurred in 22.8 % (Wistar rats inoculated with 102 cysts by the subcutaneous route), 11.4 % (Wistar rats inoculated with 102 cysts by the oral route), 21.2 % (Wistar rats inoculated with 1.2 × 103 cysts by the oral route) and 2.9 % of fetal infection (Holtzman rats inoculated with 102 cysts by the oral route). None of the pups born from chronically infected mother were infected with T. gondii.