title: Monoclonal antibody based ELISA tests to detect antibodies against neuraminidase subtypes 1, 2 and 3 of avian influenza viruses in avian sera.
abstract: The objective of this study was the development and the evaluation of competitive ELISA assays based on monoclonal antibodies for the detection of antibodies specific for neuraminidase type 1 (N1), 2 (N2) and 3 (N3) in avian sera. A total of 1450 sera from different avian species (854 negative, 185 positive to N1, 136 positive to N2, 219 positive to N3 and 56 positive to other N subtypes sera) were analysed in parallel by the three ELISAs. ROC analyses were performed to enable the selection of best cut-off values and estimation of diagnostic specificity and sensitivity. In addition, the correlation between the new developed ELISAs and the neuraminidase inhibition test was evaluated on a limited number of sera. The validation process of the three ELISAs proved excellent diagnostic performances, with very high specificity and sensitivity, ranging from 99.4 to 99.8% and from 97.6 to 100%, respectively in the three assays. The discriminating potential between antibodies elicited against homologous and heterologous N validates the test for use in "DIVA" assays, to distinguish between vaccinated and infected birds.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Via Bianchi, 9, 25124 Brescia, Italy. anamaria.morenomartin@bs.izs.it
authors.forename: Ana
authors.initials: A
authors.lastname: Moreno
authors.forename: Emiliana
authors.initials: E
authors.lastname: Brocchi
authors.forename: Davide
authors.initials: D
authors.lastname: Lelli
authors.forename: Daniela
authors.initials: D
authors.lastname: Gamba
authors.forename: Massimo
authors.initials: M
authors.lastname: Tranquillo
authors.forename: Paolo
authors.initials: P
authors.lastname: Cordioli
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000914:Antibodies, Viral / Q000097:blood*; D001717:Birds; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005585:Influenza in Birds / Q000175:diagnosis*; D051379:Mice; D008807:Mice, Inbred BALB C; D009439:Neuraminidase / Q000276:immunology*; D012680:Sensitivity and Specificity; D014764:Viral Proteins / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D014764:Viral Proteins; C487630:NA protein, influenza A virus; D009439:Neuraminidase