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Detection of Antibodies Against Toxoplasma gondii in Indian Cattle by Recombinant SAG2 Enzyme-Linked Immunosorbent Assay



A large number of recombinant proteins are tested over a period of time for diagnosis of toxoplasmosis throughout the world. However, such literature is very much limited from an Indian perspective.


The aim of the study was to assess the sero prevalence of Toxoplasma gondii in adult cattle from Kerala, India, using recombinant surface antigen 2 (recSAG2) protein.


An antibody detection recombinant ELISA specific for T gondii was laboratory-standardized using recSAG2 protein. The optimum antigen concentration, serum concentration, and conjugate dilutions were determined by the initial checkerboard titrations. Subsequently, the diagnostic potential of the recombinant protein was assessed with 258 field sera samples cattle and compared with indirect fluorescent antibody test (IFAT).


Among the cattle sera tested, 61.5% showed sero positivity of T. gondii-speciic IgG. When compared to IFAT, the sensitivity of the recSAG2 ELISA was found to be 80.00% with 88.57% specificity at 95% confidence interval with substantial agreement between the tests.


The results of present study have revealed the presence of high seroprevalence of the parasite and, hence, immense public health significance.

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The authors acknowledge Dr J P Dubey, USDA, Beltsville, USA, for providing the reference sera. The authors are also thankful to the Director, Indian Veterinary Research Institute for providing the facilities as well as to the ICAR for the fellowship awarded to the first author during the perusal of his master’s programme.

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Correspondence to Vikrant Sudan.

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Sudan, V., Tewari, A.K. & Singh, H. Detection of Antibodies Against Toxoplasma gondii in Indian Cattle by Recombinant SAG2 Enzyme-Linked Immunosorbent Assay. Acta Parasit. 64, 148–151 (2019).

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  • Cattle
  • IFAT
  • India
  • rec-SAG2-ELISA
  • Toxoplasma gondii