Chimeric protein designed by genome scale immunoinformatic enhances serodiagnosis of bovine neosporosis.

Neosporosis has become a concern since it is associated with abortion in cattle. Nowadays, in situ diagnosis is given through anamnesis, evaluation of the history and perception of the clinical signs of the herd. There is no practical and non-invasive test adapted to a large number of samples, which represents a gap for the use of new approaches that provide information about infections and risks of herds. Here, we performed a search in Neospora caninum genome by linear B-cell epitopes using immunoinformatic tools aiming to develop a chimeric protein with high potential to bind specifically to antibodies from infected cattle samples. An ELISA assay with the new chimeric antigen was developed and tested with sera from natural field N. caninum infected bovines. The cross reactivity of the new antigen was also evaluated using sera from bovines infected by others abortive pathogens including Trypanosoma vivax, Leptospira sp., Mycobacterium bovis, Brucella abortus and enzootic bovine leucosis caused by bovine leukemia virus, as well as with samples of animals infected with Toxoplasma gondii. The assay using the chimeric protein showed 96.6% (±3.4) of sensitivity in comparison with healthy animal9s sera. Meanwhile, in relation to false-positive results provided by cross-reactivity with others pathogens, the specificity value was 97.0% (±2.9). In conclusion, immunoinformatic tools provide an efficient platform to build an accurate protein to diagnosis bovine neosporosis based on sera samples.