A novel Toxoplasma gondii interspersed repeat element (TgIRE), present in most of the tachyzoite chromosomes, was characterised. Two regions on the TgIRE sequence showed high identity to two different T. gondii expressed sequence tag cDNAs of unknown function, which seems to be TgIRE pseudogenes. Two set of primers were designed, 2-2' and 2-3, that amplify products of 1.02 and 0.62 kb, respecti...

Toxoplasma gondii (T. gondii) is a protozoan parasite that infects a wide range of intermediate hosts, including all mammals and birds. Up to 20% of the human population in the US and 30% in the world are chronically infected. This paper presents a mathematical model to describe intra-host dynamics of T. gondii infection. The model considers the invasion process, egress kinetics, interconversio...

By using stage-specific monoclonal antibodies, an in vitro model has been developed to analyze the kinetics of expression of stage-specific antigens during the conversion process between tachyzoites and bradyzoites of Toxoplasma gondii. Following infection of murine macrophages with bradyzoites, the expression of bradyzoite-specific antigens declined, whereas the expression of tachyzoite-specif...

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...

OBJECTIVES We sought to improve upon the usefulness of artemisinins as anti-Toxoplasma agents by synthesizing new unsaturated, carba derivatives and then testing them for in vitro efficacy against three steps of the lytic cycle of Toxoplasma gondii tachyzoites. METHODS Novel derivatives of ART were synthesized and then tested for in vitro antiparasitic activity using T. gondii tachyzoites con...

Toxoplasma gondii is a protozoan parasite of great importance to human and animal health. In the host, this obligate intracellular parasite persists as a tissue cyst that is imperceptible to the immune response and unaffected by current therapies. The tissue cysts facilitate transmission through predation and give rise to chronic cycles of toxoplasmosis in immunocompromised patients. Transcript...

BACKGROUND Toxoplasmosis is considered as one of the most common infectious diseases caused by the protozoan parasite Toxoplasma gondii. Tachyzoite is the main form of Toxoplasma and continuously is maintained in cell culture or injected into the mice peritoneal cavity. This study was designed to evaluate the survival rate of RH strain of T. gondii tachyzoites in different cell free, nutrient a...

Serologic tests are widely accepted for diagnosing Toxoplasma gondii but purification and standardization of antigen needs to be improved. Recently, surface tachyzoite and bradyzoite antigens have become more attractive for this purpose. In this study, diagnostic usefulness of 3 recombinant antigens (SAG1, SAG2, and SAG3) were evaluated, and their efficacy was compared with the available commer...