Cultivation of Toxoplasma in Embryonated Egg. An Antigen Derived from Choriolallantoic Membrane

Abstract

Inoculation of Toxoplasma into the chorioallantoic space of 8- to 10-day embryonated eggs resulted in a fatal parasitemia in approx. 8 days. The organisms were numerous in the brain and chorioallantoic membranes, and regularly produced macroscopic lesions in the latter. A complement-fixing antigen was prepared from infected chorioallantoic membranes which gave specific reactions with high dilutions of hyperimmune monkey and guinea pig sera. This antigen also reacted with human convalescent sera from cases of clinical toxoplasmosis. It elicited a cutaneous reaction in one adult patient in whom complement-fixing and neutralizing antibodies for Toxoxlasma were also present.