title: Recombinant nucleocapsid protein is potentially an inexpensive, effective serodiagnostic reagent for infectious bronchitis virus.
abstract: The nucleocapsid protein of the Gray strain of infectious bronchitis virus (IBV) is highly immunogenic and cross-reactive among various distinct serotypes. Recombinant nucleocapsid polypeptide expressed in bacteria with a histidine tag at the amino terminus has been used as antigen for developing an assay to detect IBV-specific antibody. This fusion protein was produced readily in bacteria and easily purified with a nickel column which bound to the histidine tag. Conditions were optimized for using these preparations for an IBV-specific ELISA. Although differences in optical densities could be detected between pre-immune and positive sera for the Ark, Mass, and Gray strains with antigen concentrations between 50 and 0.1 microg per well, the greatest differences could be detected with 3 and 1.5 microg of protein per well. Maximum differences in optical densities between pre-immune and positive sera were obtained using 2.4 microg per well of protein and sera diluted between 1:80 and 1:160. In addition, as little as 30 ng/dot of recombinant nucleocapsid consistently detected IBV-specific sera in immunoblot assays which have convenient field applications.
authors.affiliation: Animal Health Research Center, Kampala, Uganda.
authors.forename: A
authors.initials: A
authors.lastname: Ndifuna
authors.forename: A K
authors.initials: AK
authors.lastname: Waters
authors.forename: M
authors.initials: M
authors.lastname: Zhou
authors.forename: E W
authors.initials: EW
authors.lastname: Collisson
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D015153:Blotting, Western / Q000662:veterinary; D002645:Chickens; D018352:Coronavirus Infections / Q000175:diagnosis / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D004926:Escherichia coli / Q000235:genetics; D015151:Immunoblotting / Q000662:veterinary*; D001351:Infectious bronchitis virus / Q000276:immunology*; D019251:Nucleocapsid / Q000235:genetics / Q000276:immunology*; D011201:Poultry Diseases / Q000175:diagnosis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D011993:Recombinant Fusion Proteins