title: Development of indirect enzyme-linked immunosorbent assay with nucleoprotein as antigen for detection and quantification of antibodies against avian influenza virus.
abstract: Avian influenza (AI) is a serious infectious disease caused by avian influenza virus (AIV) belonging to type A Orthomyxovirus. In the present study, we developed an indirect enzyme-linked immunosorbent assay (ELISA) employing E. coli-expressed full-length nucleoprotein (NP) of H9N2 avian influenza virus for the detection and quantification of antibodies against AIV nucleoprotein. The NP-ELISA was compared with the AI agar gel propagation (AGP) test, haemagglutination inhibition (HI) test, and IDEXX-FlockChek ELISA using 263 sera. The NP-ELISA was significantly more sensitive than the AGP and HI tests, and showed 96.2% agreement ratio with IDEXX-FlockChek ELISA. With results obtained using the NP-ELISA, an ELISA titre (ET) prediction equation, with which the ELISA titres of a flock or individual chickens can be determined, was derived from a positive/negative (P/N) ratio standard curve. The NP-ELISA enables an alternative rapid serological diagnosis and is suitable for influenza A antibody screening, especially in species that harbour several influenza subtypes.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China.
authors.forename: R
authors.initials: R
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: D
authors.initials: D
authors.lastname: Shi
authors.forename: D
authors.initials: D
authors.lastname: Bi
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis* / Q000276:immunology; D000956:Antigens, Viral / Q000032:analysis* / Q000276:immunology; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay / Q000191:economics / Q000379:methods / Q000662:veterinary*; D053127:Influenza A Virus, H9N2 Subtype / Q000276:immunology* / Q000302:isolation & purification; D005585:Influenza in Birds / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D009698:Nucleoproteins / Q000032:analysis* / Q000276:immunology*; D011201:Poultry Diseases / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D009698:Nucleoproteins