Prolonged Laboratory Maintenance of Toxoplasma gondii Tachyzoites in Co-cultivation with the Bovine Theileria annulata-Infected Lymphoblastoids

In most of the studies, Toxoplasma gondii is maintained in laboratory mice or studied in vitro using non-lymphoid cell lines or primary mouse macrophages. The target of our research was to design a new axenic culture of Toxoplasma gondii tachyzoites to providing a sufficient quantity of them.

Theileria annulata-infected lymphoblastoids, which had been maintained up to 260 sub-cultures to attenuate the Theileria annulata, were evaluated for their suitability to the cultivation of Toxoplasma gondii tachyzoites. This cultivation process was carried out continuously for up to 10 passages, and after each 5 sub-culture, 0.1 ml of culture suspension (1×106 tachyzoites) was inoculated to each BALB/c mouse.

It was observed that the tachyzoites have attacked the lympho-blastoids, multiplied inside them, and many fresh tachyzoites with typical shape and gliding movement were present in the culture suspension. In all processes of cultivation, the pathogenesis of parasites remained stable, and they were able to proliferate in mice and eventually lead to the death of the animals.

We describe here a new protocol for prolonged maintenance of tachyzoites of Toxoplasma gondii, which is more efficient (both in terms of yield and cost (it does not need fetal calf serum)) than other traditional methods for maintenance of the parasite.