title: Toxoplasma gondii: Recombinant GRA5 antigen for detection of immunoglobulin G antibodies using enzyme-linked immunosorbent assay.
abstract: In this study, for the first time, the evaluation of Toxoplasma gondii full-length recombinant GRA5 antigen for the serodiagnosis of human toxoplasmosis is shown. The recombinant GRA5 antigen as a fusion protein containing His-tag at both terminals was obtained using an Escherichia coli expression system. The usefulness of rGRA5 for the diagnosis of toxoplasmosis in an ELISA was tested on a total of 189 sera from patients with different stages of the infection and 31 sera from sero-negative individuals, obtained during routine diagnostic tests. Anti-GRA5 IgG antibodies were detected in 70.9% of all seropositive serum samples. This result was comparable to ELISA using a Toxoplasma lysate antigen (TLA) and six combinations of recombinant antigens. The sensitivity of IgG ELISA calculated from all positive serum samples was similar for TLA (94.2%), rMAG1+rSAG1+rGRA5 (92.6%), rGRA2+rSAG1+rGRA5 (93.1%) and rROP1+rSAG1+rGRA5 (94.2%) cocktails, whereas the sensitivity of cocktails without rGRA5 antigens was lower giving 82.0%, 86.2% and 87.8%, respectively. Thus, the present study showed that the full-length rGRA5 is suitable for use as a component of an antigen cocktail for the detection of anti-T. gondii IgG antibodies.
authors.affiliation: Gdańsk University of Technology, Chemical Faculty, Department of Microbiology, Narutowicza 11/12 Str., 80-233 Gdańsk, Poland.
authors.forename: Lucyna
authors.initials: L
authors.lastname: Holec-Gasior
authors.forename: Józef
authors.initials: J
authors.lastname: Kur
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C095046:GRA5 protein, Toxoplasma gondii; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D011994:Recombinant Proteins