title: Development of a highly sensitive and specific enzyme-linked immunosorbent assay based on recombinant matrix protein for detection of avian pneumovirus antibodies.
abstract: The matrix (M) protein of avian pneumovirus (APV) was evaluated for its antigenicity and reliability in an enzyme-linked immunosorbent assay (ELISA) for diagnosis of APV infection, a newly emergent disease of turkeys in United States. Sera from APV-infected turkeys consistently contained antibodies to a 30-kDa protein (M protein). An ELISA based on recombinant M protein generated in Escherichia coli was compared with the routine APV ELISA that utilizes inactivated virus as antigen. Of 34 experimentally infected turkeys, 33 (97.1%) were positive by M protein ELISA whereas only 18 (52.9%) were positive by routine APV ELISA 28 days after infection. None of the serum samples from 41 uninfected experimental turkeys were positive by M protein ELISA. Of 184 field sera from turkey flocks suspected of having APV infection, 133 (72.3%) were positive by M protein ELISA whereas only 99 (53.8%) were positive by routine APV ELISA. Twelve serum samples, which were negative by M protein ELISA but positive by routine APV ELISA, were not reactive with either recombinant M protein or denatured purified APV proteins by Western analysis. This indicates that the samples had given false-positive results by routine APV ELISA. The M protein ELISA was over six times more sensitive than virus isolation (11.5%) in detecting infections from samples obtained from birds showing clinical signs of APV infection. Taken together, these results show that ELISA based on recombinant M protein is a highly sensitive and specific test for detecting antibodies to APV.
authors.affiliation: Departments of Veterinary Diagnostic Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55108, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Gulati
authors.forename: K T
authors.initials: KT
authors.lastname: Cameron
authors.forename: B S
authors.initials: BS
authors.lastname: Seal
authors.forename: S M
authors.initials: SM
authors.lastname: Goyal
authors.forename: D A
authors.initials: DA
authors.lastname: Halvorson
authors.forename: M K
authors.initials: MK
authors.lastname: Njenga
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018111:Pneumovirus / Q000276:immunology* / Q000302:isolation & purification; D018186:Pneumovirus Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D011201:Poultry Diseases / Q000175:diagnosis / Q000821:virology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014422:Turkeys; D014763:Viral Matrix Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D011994:Recombinant Proteins; D014763:Viral Matrix Proteins