Development of an Immunochromatographic Test with Recombinant MIC2-MIC3 Fusion Protein for Serological Detection of Toxoplasma gondii

<i>Toxoplasma gondii</i> is a globally significant zoonotic pathogen responsible for severe parasitic diseases in humans and animals. This study aimed to design, develop, and evaluate a novel immunochromatographic test (ICT) using a recombinant MIC2-MIC3 fusion protein (rMIC2-MIC3) for detecting specific antibodies against <i>T. gondii</i>. The ICT demonstrated exceptional sensitivity, capable of detecting <i>T. gondii</i>-specific antibodies in sera diluted up to 1:8. Specificity evaluation confirmed no cross-reactivity with antibodies against other parasites, such as <i>Neospora caninum, Cryptosporidium suis, Eimeria tenella</i>, and <i>Sarcocystis tenella</i>. Stability tests revealed the test strips maintained full functionality after 12 weeks of storage at 24 °C. The coincidence rate of the colloidal gold test strips prepared in this study with a commercial ELISA kit was 94.59%. Comparisons with advanced serodiagnostic tools, such as chimeric antigen-based ELISAs and recombinant protein diagnostics, further highlighted its robustness and applicability. These findings underscore the potential of the rMIC2-MIC3-based ICT as a reliable, economical, and accessible diagnostic tool for toxoplasmosis in veterinary and human medicine.