Characterization of a novel murine model of Toxoplasma gondii infection using oocysts of a recently obtained Type III isolate.

Type II reference isolates of Toxoplasma gondii are widely used in animal toxoplasmosis models, but studies with Type III isolates remain scarce. In addition, these methods often rely on laboratory-adapted parasite stages that may not reflect natural infection. This study presents a new murine model based on an oral infection with oocysts from a recently obtained Type III isolate, TgShSp24, which exhibited remarkable morbidity and a distinct tissue distribution during chronic infection, differing from the recently obtained Type II isolate TgShSp1. This novel model aims to better mimic natural infection and provides a valuable tool for testing drugs and vaccines.