Development of a bead-agglutination assay for rapid detection of Tritrichomonas foetus

Tritrichomonas foetus is a flagellated protozoan parasite that causes inflammation of the reproductive tract leading to early embryonic death and abortion in cattle, thereby resulting in significant economic losses. Testing and culling infected bulls is an important strategy for parasite control. Routine testing is mainly limited to bulls that are traveling across state lines or within states that have specific control programs. Both culture and PCR detection methods are available, but they are not typically conducted as part of a yearly breeding soundness program and are not easily conducted in the field. In the present study, we developed a bead agglutination assay for detection of T. foetus antigens. Our experiments revealed that latex beads conjugated to T. foetus lipophosphoglycan-binding antibodies visibly clump in the presence of T. foetus. The detection limit of the assay, determined using both field and laboratory isolates of the parasite, was 0.25 μg/mL and 1.0 μg/mL total T. foetus antigen, respectively. Our results indicate that an antigen detection test could offer a tool for screening bulls under field conditions.