title: Diagnostic application of recombinant equine merozoite surface antigen-1 in elisa for detection of Theileria equi specific antibodies.
abstract: Theileria equi merozoite surface antigens have been an important candidate for development of diagnostics. We developed ELISA based on EMA-1 recombinant antigen, so as to widen our diagnostic confidence in detection of antibodies against T. equi in sero-surveillance studies. The 547 bp EMA-1 gene fragment encoding high hydrophilic antigenic region was expressed with glutathione-S-transferase tag in prokaryotic system and purified protein (43 kDa) was used for development of ELISA (EMA-1t/ELISA). The EMA-1t/ELISA clearly differentiated T. equi-infected from Babesia caballi-infected horse sera or normal horse sera. The results of the study were validated with previously developed (EMA-2)ELISA on serum samples of known T. equi infection status and a very high correlation (0.93) was recorded between the relative percent positivity (RPP) values. Further diagnostic sensitivity of EMA-1t/ELISA was 0.92 while specificity was 1.0, indicating its suitability for sero-epidemiological studies. This assay was applied on serum samples (n = 240) collected from field horses in northern part of India. High sero-prevalence of T. equi antibodies were diagnosed in serum samples collected from Haryana state (74%) and Uttarakhand state (36.31%). Results of this study suggested that the 43 kDa EMA-1 expressed protein could be a reliable immunodiagnostic antigen in ELISA for T. equi sero-prevalence studies.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.forename: Naresh K
authors.initials: NK
authors.lastname: Rakha
authors.forename: Liza
authors.initials: L
authors.lastname: Goyal
authors.forename: Parveen
authors.initials: P
authors.lastname: Goel
authors.forename: Rajender
authors.initials: R
authors.lastname: Kumar
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kumar
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis* / Q000469:parasitology; D006736:Horses; D020066:Merozoite Surface Protein 1 / Q000276:immunology*; D016794:Theileria / Q000276:immunology* / Q000302:isolation & purification; D013801:Theileriasis / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D000953:Antigens, Protozoan; D020066:Merozoite Surface Protein 1