OBJECTIVES We compared the reactivity of IgG1 and IgG2a antibodies in mouse sera after infection with virulent RH and low-virulent S273 and Beverley strains of Toxoplasma gondii against RH SAG1 recombinant p30 (rp30) and synthetic SAG1 peptides. METHODS Infected mouse serum samples were collected 9 days after infection, and the level of total IgG, IgG1 and IgG2a against the RH SAG1 rp30 prote...

genetic typing methods of t. gondii strains have been extensively perfected in recent years. from a technical point of view, many tools usable for genetic studied on single-copy loci have been used: rflp, pcr-rflp, sequencing, rapd-pcr and isoenzyme analysis. we described the cloning and sequence analysis of the gene which encodes the major surface antigen (sag1 or p30) of t. gondii. sag1 is th...

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...

Toxoplasma gondii has an unusual population structure consisting of three widely distributed clonal lineages. Acute virulence in mice is strictly observed in type I strains, indicating that a genetic determinant(s) unique to this lineage controls acute pathogenesis. We have analyzed several naturally occurring recombinant strains of T. gondii that carry allele 1 at the SAG1 locus; this allele i...

BACKGROUND The assays currently available for the detection of specific anti-Toxoplasma antibodies may vary in their abilities to detect serum immunoglobulins, due to the Lack of a purified standardized antigen. The aim of this study was evaluation the recombinant Toxoplasma gondii SAG1 antigen for the serodiagnosis of acute and chronic toxoplasmosis. METHODS This study describes an ELISA usi...

The SAG1 Toxoplasma gondii surface protein stimulates acute ileitis. To determine whether SAG1 is also important in the eye, wild-type or SAG1 knockout parasites were injected intravitreally into mice. No differences in retinal damage or parasite growth were observed, indicating that unlike the case for the intestine, factors besides SAG1 are important for retinal damage.

background: toxoplasma gondii is an obligate intracellular parasite and its sexual and asexual cycles, respectively take place in the intestinal epithelial cell of definitive host and tissue of intermediate hosts. congenital toxoplasmosis is more impor tant when the mother acquired the infection during pregnancy period for the first time. serological tests are the only meth ods for diagnosis of...

A combinatorial immunoglobulin gene library was constructed from lymphocytes in peripheral blood of a patient with toxoplasmosis and screened for production of human monoclonal antibody Fab fragments to recombinant surface antigen 1 (SAG1) of Toxoplasma gondii. Two Fab clones, Tox203 and Tox1403, which consisted of a common heavy chain and different light chains, showed positive staining on the...

Infection of Neospora caninum causes abortion in cattle, which has a serious worldwide impact on the economic performance of the dairy and beef industries. Now, inexpensive and efficacious vaccines are required to protect cattle from neosporosis in livestock industry. In this study, N. caninum surface antigen 1 (SAG1) and SAG1-related sequence 2 (SRS2) were expressed in hemolymph of silkworm la...