A time-resolved fluorescence immunoassay for the detection of anti-Neospora caninum antibodies in sheep

Publication date: Available online 19 November 2019Source: Veterinary ParasitologyAuthor(s): Ana Huertas-López, Carlos Martínez-Carrasco, José Joaquín Cerón, Roberto Sánchez-Sánchez, Ángela Vázquez-Calvo, Gema Álvarez-García, Silvia Martínez-SubielaAbstractNeospora caninum is a protozoan parasite (Phylum Apicomplexa) that has been recently suggested as a relevant cause of reproductive disorders in small ruminants. The aim of the present study is to develop and validate a new serological test based on time resolved fluorescency using N. caninum GRA7 recombinant antigen (GRA7-TRFIA) for the detection of N. caninum antibodies in sheep. A total of 346 serum samples (208 from experimentally infected sheep, 117 from a dairy farm with a previous history of Neospora-associated abortion, and 21 negative sera) were used. The validation of the new assay was performed by the evaluation of assay precision, analytical sensitivity (Se), accuracy and cross reactivity. In the experimentally infected sheep, antibody kinetics was compared between GRA7-TRFIA and an in house N. caninum tachyzoite soluble extract-based ELISA (NcSALUVET ELISA) by Wilcoxon matched-pairs signed rank test. The cut-off and diagnostic Se and specificity (Sp) of GRA7-TRFIA was estimated by ROC analysis with field samples. In addition, concordance and correlation between GRA7-TRFIA and a commercial ELISA and NcSALUVET ELISA were assessed by kappa value and Spearman correlation coefficient, respectively.Overall...
Source: Veterinary Parasitology - Category: Veterinary Research Source Type: research