title: Development of a multi-epitope antigen of S protein-based ELISA for antibodies detection against infectious bronchitis virus.
abstract: An indirect enzyme-linked immunosorbent assay (ELISA) method based on a novel multi-epitope antigen of S protein (SE) was developed for antibodies detection against infectious bronchitis virus (IBV). The multi-epitope antigen SE protein was designed by arranging three S gene fragments (166-247 aa, S1 gene; 501-515 aa, S1 gene; 8-30 aa, S2 gene) in tandem. It was identified to be approximately 32 kDa as a His-tagged fusion protein and can bind IBV positive serum by western blot analysis. The conditions of the SE-ELISA method were optimized. The optimal concentration of the coating antigen SE was 3.689 μg/mL and the dilution of the primary antibodies was identified as 1:1000 using a checkerboard titration. The cut-off OD450 value was established at 0.332. The relative sensitivity and specificity between the SE-ELISA and IDEXX ELISA kit were 92.38 and 89.83%, respectively, with an accuracy of 91.46%. This assay is sensitive and specific for detection of antibodies against IBV.
authors.affiliation: a School of Life Science , Sichuan University, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, "985 Project" Science Innovative Platform for Resource and Environment Protection of Southwestern China , Chengdu , China.
authors.forename: Meng-Die
authors.initials: MD
authors.lastname: Ding
authors.forename: Hong-Ning
authors.initials: HN
authors.lastname: Wang
authors.forename: Hai-Peng
authors.initials: HP
authors.lastname: Cao
authors.forename: Wen-Qiao
authors.initials: WQ
authors.lastname: Fan
authors.forename: Bing-Cun
authors.initials: BC
authors.lastname: Ma
authors.forename: Peng-Wei
authors.initials: PW
authors.lastname: Xu
authors.forename: An-Yun
authors.initials: AY
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000956:Antigens, Viral / Q000276:immunology; D002645:Chickens / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D001351:Infectious bronchitis virus / Q000276:immunology / Q000302:isolation & purification*; D064370:Spike Glycoprotein, Coronavirus / Q000276:immunology*
chemical_list: D000906:Antibodies; D000956:Antigens, Viral; D000939:Epitopes; D064370:Spike Glycoprotein, Coronavirus; C578554:spike protein, avian infectious bronchitis virus
keywords: ELISA; antibodies; infectious bronchitis virus (IBV); multi-epitope antigen