title: Single dilution Avidity-Blocking ELISA as an alternative to the Bovine Viral Diarrhea Virus neutralization test.
abstract: This study describes the development and validation of a blocking ELISA that measures avidity of BVDV-specific immunoglobulins (Igs) as an alternative to the classic virus neutralization test. The assay comprises a recombinant soluble E2 glycoprotein as target antigen, a neutralizing serum as detector antibody and a washing-step with a chaotropic agent to determine BVDV-specific Igs avidity. Avidity-Blocking ELISA was validated with 100 negative and 87 positive BVDV-neutralization serum samples from either infected or vaccinated bovines (inactivated commercial vaccines). Specificity and sensitivity of the Avidity-Blocking ELISA were 100% and 98.8%, respectively. The assay was standardized to use a single dilution, so that 90 samples can be tested per plate. Results expressed as Avidity Index (AI) correlated with BVDV neutralizing titers (r=0.94). Unlike the virus neutralization test, the Avidity-Blocking ELISA could discriminate between infected and vaccinated animals (DIVA), suggesting that avidity measurement can be a valuable tool to achieve DIVA compliances. The data show that the avidity of anti BVDV antibodies is related to their capacity to block viral infection in vitro.
authors.affiliation: Instituto de Ciencia y Tecnología Dr. César Milstein, Saladillo 2468, 1440, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: O L
authors.initials: OL
authors.lastname: Franco Mahecha
authors.forename: M L
authors.initials: ML
authors.lastname: Ogas Castells
authors.forename: G
authors.initials: G
authors.lastname: Combessies
authors.forename: M A
authors.initials: MA
authors.lastname: Lavoria
authors.forename: M
authors.initials: M
authors.lastname: Wilda
authors.forename: F C
authors.initials: FC
authors.lastname: Mansilla
authors.forename: C
authors.initials: C
authors.lastname: Seki
authors.forename: P R
authors.initials: PR
authors.lastname: Grigera
authors.forename: A V
authors.initials: AV
authors.lastname: Capozzo
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D002417:Cattle; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003967:Diarrhea / Q000821:virology*; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D009500:Neutralization Tests / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral