Use of the enzyme-linked immunosorbent assay for the detection of toxoplasmosis in swine

This study was conducted to evaluate the possibility of application of a micro-enzyme-linked immunosorbent assay (micro-ELISA) for the serodiagnosis of specific toxoplasma antibodies in swine sera and this test was performed as a microplate system by coating the polystyrene plates with toxoplasma soluble antigen, incubated serially diluted sera, then added horse radish peroxidase labelled goat anti-swine IgG(r) conjugate followed by o-phenylenediamine as substrate. The color development by enzyme-substrate reaction was determined by the photometric reading [ELISA reader at 490nm (OD)] and visual reading. The soluble antigen was prepared from the tachyzoites in mouse peritoneal cavity. A total of 1,200 swine sera from pig slaughter-house and a total of 116 swine sera from pig breeding station (S-C farm) were tested for the detection of antibodies to Toxoplasma gondii. The optimal reactions of indirect ELISA for the test sera were determined by the dilution of antigen 1:256 and 1:3,200 of horse radish peroxidase conjugate [anti-swine IgG (r)]. The specific toxoplasma antibody (IgG) in pigs infected with Tp artifically were detected as the serum titers of 1:64 or 1:128 at one week postinfection. Of a total of 1,200 swine sera from pig slaughter-house 505 samples of sera were detected as positive (42.1 %) and of a total of 116 swine sera from S-C pig breeding station 68 samples of sera as positive (58.6 %). The specific antibody (IgG) detection rates against a total of 1,200 test sea from pig slaughter-house were not significant between male (43.1 %) and female (40.7 %). The indirect ELISA was proved to be a sensitive and specific procedure for the serodiagnosis of swine toxoplasmosis and also evaluated as an effective screening test for the large scale of test samples in laboratory