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 ...

To examine the immune environment of chronic Toxoplasma gondii infection in the brain, the characteristics of infection-immunity (premunition) in infection with T. gondii strain ME49 were investigated for 12 weeks postinfection (PI). The results showed that neuronal cell death, microglia infiltration and activation, inflammatory and anti-inflammatory cytokine expression, Stat1 phosphorylation, ...

background: toxoplasma gondii , an apicomplexan parasite, is capable of infecting a broad range of intermediate warm-blooded hosts including humans. the parasite seems to be capable of altering the natural behavior of the host to favor its trans-mission in the environment. the aim of this study was to evaluate the course, alter-ations in behavior along with normal kinetics of the abnormally ind...

Neospora caninum and Toxoplasma gondii are cyst-forming coccidian parasites of human and veterinary clinical relevance. In vitro cultivation of the protozoans using Vero cells is usually performed in order to produce antigenic materials. Quantitative and qualitative comparisons of Vero cells grown in RPMI medium supplemented either with foetal calf serum (FCS), horse serum (HS) or a specific se...

Neospora caninum (N. caninum) is an apicomplexan parasite and causes abortion and congenital neosporosis in cattle worldwide. In this study, we evaluate the virulence of a N. caninum isolate on mouse strain C57BL/6. Six groups of five mice C57BL/6 were intraperitoneally inoculated with 1 × l07, 1.5 × l07, 2 × l07, 3 × l07 and 4 × l07 tachyzoites and a control inoculum of DMEM, respectively. Cli...

The triazine WR99210 [4,6-diamino-1,2-dihydro-2,2-dimethyl-1-(2,4,5-trichlorophenoxypropyloxy)-1,3,5 triazine] inhibits Toxoplasma gondii in vitro at nanomolar levels (P < 0.05). The 50% inhibitory concentration (IC(50)) was approximately 50 nM. It is a potent inhibitor in vitro and is also effective in vivo. Administration of WR99210 parenterally (i.e., intraperitoneally) reduced the mean numb...

Background: Dense granule antigens (GRA antigens) of Toxoplasma gondii induce strong antibody response in humans and are considered as useful diagnostic antigens. Previous studies reported expression of amino terminal GRA8 protein in fusion with large tags such as glutathione-S-transferase. The present study aimed to produce soluble full length immunogenic GRA8 in bacteria. Methods: GRA8 comple...

Toxoplasma gondii is the causative agent for toxoplasmosis. The rhoptry protein 1 (ROP1) is secreted by rhoptry, an apical secretory organelle of the parasite. ROP1 plays an important role in host cell invasion. In this study, the efficacy of ROP1 as a vaccine candidate against toxoplasmosis was evaluated through intramuscular or subcutaneous injection of BALB/c mice followed by immunological c...

Parasitic protozoa such as the apicomplexan Toxoplasma gondii progress through their life cycle in response to stimuli in the environment or host organism. Very little is known about how proliferating tachyzoites reprogram their expressed genome in response to stresses that prompt development into latent bradyzoite cysts. We have previously linked histone acetylation with the expression of stag...

Toxoplasma gondii can lead to congenital infections in human. Surface antigen protein 4 (SAG4) of T. gondii is a potential stimulator for humoral and cellular immune responses. In the present study, a DNA vaccine encoding SAG4 from T. gondii was constructed and used to immunize BALB/c mice with peptide to evaluate the protective efficacy of the vaccine. The productions of IgG antibodies and cyt...