Comparative diagnostic performance of recombinant Tams1 protein based dot-ELISA in detecting tropical theileriosis in naturally infected cattle.

This study is the first to conduct a sero-surveillance of Bovine Tropical Theileriosis (BTT) caused by the protozoan parasite Theileria annulata (T. annulata) using a recombinant Tams1 protein-based dot-ELISA in cattle, and to compare its efficacy with plate-ELISA, single PCR, nested PCR, and blood microscopy. The goal was to identify the most effective method for the early and accurate detection of theileriosis, which significantly impacts livestock through reduced milk yield and increased mortality. A total of 101 field blood samples were examined using blood smear analysis, single PCR, nested PCR, and dot-ELISA. The recombinant Tams1 protein was successfully cloned and expressed using a pET-30b (+) expression vector in a prokaryotic system. The protein was purified with Ni-NTA chromatography, confirmed for immunoreactivity with T. annulata positive serum via Western blot analysis, and used to optimize both dot-ELISA and plate-ELISA. Both dot-ELISA and plate-ELISA using recombinant Tams1 protein exhibited comparable diagnostic performance, with a kappa value of 0.826 and similar analytical productivity (P = 0.6165). Dot-ELISA revealed a BTT seroprevalence of 58.4% in the cattle population, demonstrating good sensitivity (93.33%) and specificity (90%). The diagnostic performance of dot-ELISA was found to be superior to other molecular techniques, including microscopy, single PCR, and nested PCR. Dot-ELISA is also a sustainable solution in comparison to other laboratory diagnostic techniques with benefits of early diagnosis, reduced waste generation, resource efficiency, cost-effective point of care disease surveillance. With its minimal antigen requirement, Tams1 molecule based dot-ELISA is recommended as an effective tool for epidemiological studies and field surveys of BTT.