title: Characterization of field and vaccine infectious bursal disease viruses from Nigeria revealing possible virulence and regional markers in the VP2 minor hydrophilic peaks.
abstract: Outbreaks of infectious bursal disease in vaccinated chicken flocks are frequent in Nigeria. For the control of infectious bursal disease, live vaccines based on foreign infectious bursal disease virus (IBDV) strains are used. The present study investigated the phylogenetic relationship between field and vaccine IBDV strains from northwestern Nigeria. Thirty field IBDV strains and three commercial vaccines strains were characterized through sequencing the VP2 hypervariable region. In addition, the complete genome segment A coding region for two vaccines and two field strains was sequenced. The deduced amino acid sequences (position 212 to 331) of IBDV strains from Nigeria and other regions of the world were aligned and possible regional and virulence markers were identified associated with VP2 minor hydrophilic peaks. Reversion to virulence of a vaccine strain with a Q to L mutation at position 253 was observed. Phylogenetic analyses revealed a unique cluster of northwest Nigerian field IBDV strains alone or related to imported characterized classical and very virulent IBDV vaccines. The results suggest that when IBDV strains spread from their region of origin to a different region they mutate alongside indigenous field strains but may retain their identity on the VP2 region.
authors.affiliation: a Department of Veterinary Microbiology, Faculty of Veterinary Medicine , Ahmadu Bello University , Zaria , Nigeria.
authors.forename: J
authors.initials: J
authors.lastname: Adamu
authors.forename: A A
authors.initials: AA
authors.lastname: Owoade
authors.forename: P A
authors.initials: PA
authors.lastname: Abdu
authors.forename: H M
authors.initials: HM
authors.lastname: Kazeem
authors.forename: M Y
authors.initials: MY
authors.lastname: Fatihu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018175:Birnaviridae Infections / Q000662:veterinary* / Q000821:virology; D002645:Chickens / Q000821:virology*; D017931:DNA Primers / Q000235:genetics; D004196:Disease Outbreaks / Q000662:veterinary; D007243:Infectious bursal disease virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D008969:Molecular Sequence Data; D009154:Mutation; D009549:Nigeria; D010802:Phylogeny; D011201:Poultry Diseases / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA / Q000662:veterinary; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D015678:Viral Structural Proteins / Q000235:genetics*; D014765:Viral Vaccines / Q000276:immunology*; D014774:Virulence
chemical_list: D017931:DNA Primers; D012367:RNA, Viral; C082513:VP2 protein, infectious bursal disease virus; D015678:Viral Structural Proteins; D014765:Viral Vaccines