title: Development of an indirect ELISA-NcSRS2 for detection of Neospora caninum antibodies in cattle.
abstract: Neosporosis is of alarming economic concern in the cattle industry. The effectiveness of diagnostic tests for detecting specific antibodies against Neospora caninum is hampered by potential cross-reaction with other coccidia. Use of a single specific antigen might improve test specificity. An indirect enzyme-linked immunosorbent assay (ELISA) was developed using the truncated protein NcSRS2 expressed in Escherichia coli. The ELISA results were compared with those of the indirect fluorescence antibody test (IFAT). Receiver Operating Characteristic (ROC) and Tests in the Absence of a Gold Standard (TAGS) analysis revealed an assay having 96% specificity and 95% sensitivity when applied to 145 positive and 352 negative sera from two distinct cattle populations. Using OD ≤ 0.095 as the cut-off point, the assay's negative and positive predictive values ranged from 98.8% to 50.8% and from 58.8% to 99.1%, respectively, depending on neosporosis prevalence in a given area. The novel ELISA-NcSRS2 format described in the present report constitutes a specific and sensitive method for detecting N. caninum in cattle.
authors.affiliation: Departamento de Microbiologia e Parasitologia, Instituto de Biologia, UFPel, Pelotas, RS, Brazil.
authors.forename: Sibele
authors.initials: S
authors.lastname: Borsuk
authors.forename: Renato
authors.initials: R
authors.lastname: Andreotti
authors.forename: Fábio Pereira Leivas
authors.initials: FP
authors.lastname: Leite
authors.forename: Luciano da Silva
authors.initials: Lda S
authors.lastname: Pinto
authors.forename: Simone
authors.initials: S
authors.lastname: Simionatto
authors.forename: Claudia Pinho
authors.initials: CP
authors.lastname: Hartleben
authors.forename: Marcelo
authors.initials: M
authors.lastname: Goetze
authors.forename: Leandra Marla
authors.initials: LM
authors.lastname: Oshiro
authors.forename: Maria de Fátima Cepa
authors.initials: Mde F
authors.lastname: Matos
authors.forename: Maria Elisabeth Aires
authors.initials: ME
authors.lastname: Berne
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis / Q000469:parasitology*; D003048:Coccidiosis / Q000097:blood / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D018688:Neospora / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan