In Silico discovery and preliminary serological evaluation of an NcSRS2-derived synthetic peptide for the diagnosis of Neospora caninum in dogs and cattle.

Neospora caninum is an Apicomplexa parasite with a broad host range. It causes neurological disorders in dogs and is a major cause of abortion and stillbirths in cattle, leading to a significant economic impact on livestock production. An effective control of infection and transmission remains challenging, underscoring the need for more specific and reliable diagnostic tools. In this study, a novel peptide derived from the NcSAG1-related sequence 2 (NcSRS2) protein was identified through in silico analysis using multiple bioinformatics approaches. The selected peptide (SRS2p) was synthesized, purified, and characterized, and then evaluated by an enzyme-linked immunosorbent assay (ELISA) using sera from experimentally infected cattle and IFAT-characterized canine sera. The results demonstrated that SRS2p was recognized by N. caninum-positive sera, supporting its preliminary evaluation as a candidate peptide for serological diagnosis.