The use of ELISA and immunohistochemistry techniques for detection of Toxoplasma gondii antigen in tissues of experimentally infected mice.

The capability of double antibody sandwich enzyme-linked immunosorbent assay (ELISA) for detecting antigens of Toxoplasma gondii (T. gondii) in different mice tissue specimens was evaluated in comparison to the immunohistochemistry (IHC) technique. Results proved that tissue antigens were detectable in liver, kidney and mesenteric lymph node (LN) specimens by both methods from the second day of infection, with statistically significant increase in its amount in all organs throughout the period of the study. Using ELISA technique, the highest antigen level was recorded on the second day (0.120+/-0.0015) and the fourth day (0.147+/-0.0034) of infection in LN specimens, while, the liver showed the highest antigen level at the sixth day post infection (PI)(0.165+/-0.0066). On the other hand, using the IHC technique, the highest number of tachyzoites was recorded in LN sections in all studied durations, the second, the fourth and the sixth days PI (1.1+/-0.875, 1.6+/-1.173 & 3.1+/-1.370 respectively). Thus, sandwich ELISA technique might offer a valuable aid for rapid diagnosis of acute toxoplasmosis in human tissues, and it has proved to be more accurate than IHC technique, since its results was coincided with the pathogenesis of the disease.