Toxoplasma gondii infects a very wide range of mammals and birds, and about one-third of humans are infected with this protozoan parasite. Chronic T. gondii infection has historically been believed to be asymptomatic; however there is now evidence that links chronic infection with several psychiatric disorders. While there are drugs to treat acute toxoplasmosis, there are currently no treatments for the latent form of the parasite. Currently, T. gondii in vivo research is performed using murine models, which are limited by cost and the inability to perform high throughput assays. To develop an improved in vivo model, we adapted zebrafish to 37°C and injected them intraperitoneally with two strains of T. gondii at a concentration of 10 tissue cysts per fish, and observed them for 7 days post injection. Fish were examined by histology for the presence of T. gondii development. Intracellular parasites were observed in fish at 5 to 7 days post injection. The pattern of infection observed was similar to that found in mammalian infection, with parasites developing in the somatic muscle, heart, liver, spleen, kidney, and brain.
Keywords: Danio rerio; infection experiment.