Titers in a direct agglutination test using Formalin-fixed toxoplasma tachyzoites were significantly higher in patients with acquired immunodeficiency syndrome with toxoplasmic encephalitis (TE) than in those without TE. In contrast, when fresh (not fixed) tachyzoites were used, the titers did not differ from those in patients without TE. The direct agglutination test using Formalin-fixed tachy...

Toxoplasma gondii proliferates and organizes within a parasitophorous vacuole in rosettes around a residual body and is surrounded by a membranous nanotubular network whose function remains unclear. Here, we characterized structure and function of the residual body in intracellular tachyzoites of the RH strain. Our data showed the residual body as a body limited by a membrane formed during prol...

To evaluate the usefulness of the Korean Isolate-1 (KI-1) antigen for serodiagnosis of toxoplasmosis, antigen profiles of KI-1 tachyzoites were analyzed in comparison with RH tachyzoites by SDS-PAGE and immunoblotting. ELISA was performed on latex agglutination (LA)-positive and negative serum samples using KI-1 and RH antigens. Immunoblotting of the KI-1 antigen showed multiple antigen bands w...

Besnoitia sp. are apicomplexan coccidian parasites affecting several species of mammals and cold-blooded animals in several countries. Besnoitia sp. tissue cysts were seen in several tissues of five rabbits from a rabbit breeder in La Plata, Argentina. Bradyzoites released from macroscopic tissue cysts were inoculated onto bovine monocytes, and into interferon gamma gene knockout (KO) mice. Bes...

Tachyzoites, bradyzoites (in tissue cysts), and sporozoites (in oocysts) are the three infectious stages of Toxoplasma gondii. The prepatent period (time to shedding of oocysts after primary infection) varies with the stage of T. gondii ingested by the cat. The prepatent period (pp) after ingesting bradyzoites is short (3-10 days) while it is long (18 days or longer) after ingesting oocysts or ...

Macrophages exposed to 10 mug/mL citrinin (CTR) or 0.01 mug CTR mixed with 0.04 mug aflatoxin B1 (AFB1) for a period of 2 h at 37 masculine C, were infected with 10(6) Toxoplasma gondii tachyzoites/muL. The parasites were treated with mycotoxins (2 h at 37 masculine C) before being added to the macrophage culture. The number of tachyzoites was quantified 2, 24, 48, 72 and 96 h after infection. ...

AIMS To assess the diagnostic usefulness of Toxoplasma gondii tachyzoites produced by serial passage in HeLa cell culture. METHODS Tachyzoites derived from serial passage in cell culture were used in the dye test. Human sera were also examined to determine their suitability for use as accessory factor. Using the optimum conditions, the dye test using cell culture derived tachyzoites was compa...

This study investigates the temporal and spatial interchange of the aromatic amino acid phenylalanine (Phe) between human retinal pigment epithelial cell line (ARPE-19) and tachyzoites of the apicomplexan protozoan parasite Toxoplasma gondii (T. gondii). Stable isotope labelling by amino acids in cell culture (SILAC) is combined with Raman micro-spectroscopy to selectively monitor the incorpora...

Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contrib...