title: Development of an immunochromatographic assay based on dense granule protein 7 for serological detection of Toxoplasma gondii infection.
abstract: Dense granule antigen proteins derived from Toxoplasma gondii (TgGRAs) are potential antigens for the development of diagnostic tools. TgGRA7 and TgGRA14 were detected in the peritoneal fluid of T. gondii-infected mice, suggesting that TgGRAs may be highly antigenic proteins. Here, TgGRA7 and TgGRA14 were evaluated as candidates for the development of a marker for a rapid diagnostic test. The specificity and sensitivity of purified recombinant proteins of TgGRA7 and TgGRA14 were compared in an indirect enzyme-linked immunosorbent assay (iELISA) using a series of serum samples from T. gondii-experimentally infected mice and using recombinant T. gondii major surface antigen 2 (TgSAG2) as a reference control. The iELISA with TgGRA7 showed the greatest diagnostic accuracy and could detect anti-TgGRA7 antibody in acute and chronic infections. A total of 59 field samples from pigs were also examined by the iELISAs, and the results compared with those of the latex agglutination test (LAT). Among the three recombinant antigens, TgGRA7 had the highest rates of positivity, with significant concordance (88.14) and kappa value (0.76) in comparison with the results using LAT. Furthermore, an immunochromatographic test (ICT) based on recombinant TgGRA7 was developed for rapid detection of antibodies to the infection. The ICT differentiated clearly between sera from T. gondii-infected mice and uninfected or Neospora caninum-infected mice. Pig sera were examined with the ICT, and the results compared favorably with those of LAT and iELISA for TgGRA7, with kappa values of 0.66 and 0.70 to 0.79, respectively. These data suggest that the ICT based on TgGRA7 is a promising diagnostic tool for routine testing in the clinic and mass screening of samples in the field.
authors: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, Japan.
authors: Mohamad Alaa
authors: MA
authors: Terkawi
authors: Kyohko
authors: K
authors: Kameyama
authors: Nazim Hamza
authors: NH
authors: Rasul
authors: Xuean
authors: X
authors: Xuan
authors: Yoshifumi
authors: Y
authors: Nishikawa
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000235:genetics; D002846:Chromatography, Affinity / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D015800:Protozoan Proteins / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D013552:Swine; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C112573:GRA7 protein, Toxoplasma gondii; D015800:Protozoan Proteins; D011994:Recombinant Proteins