title: Infectious bronchitis vaccine virus detection and part-S1 genetic variation following single or dual inoculation in broiler chicks.
abstract: An investigation was undertaken of the extent of genetic variation occurring within infectious bronchitis virus (IBV) vaccine strains following vaccination of day-old broiler chicks. Chicks were divided into seven groups, with two groups receiving single Massachusetts (Mass) vaccinations while the other four were inoculated with combinations of different IBV serotypes; Mass, 793B, D274 and Arkansas (Ark). The remaining group was maintained as an unvaccinated control. Following vaccination, swabs and tissues collected at intervals were pooled and RNA was extracted for detection of IBV by reverse transcription polymerase chain reaction. Positive amplicons were sequenced for the part-S1 gene and compared to the original vaccine strain sequences. Single nucleotide polymorphisms, amino acid variations and hydrophobicity changes were identified and recorded for each sampling point. A total of 106 single nucleotide polymorphisms were detected within 28 isolates. The average single nucleotide polymorphism counts of swab isolates were greater than those found in tissue samples. This translated into 64 amino acid changes; however only six resulted in a change to the hydrophobicity properties. All hydrophobic alterations occurred within swab isolates and the majority were recovered at 3 days post vaccination suggesting such changes to be detrimental to early virus survival. Nucleotide deletions were seen only in the group given the combination of Mass and Ark. Of the 16 sequenced samples in this group, 13 contained the same AAT deletion at position 1033 1035 in the Ark strains. Findings presented in this study demonstrate alteration in the S1 nucleotide sequence following co-administration of live IBV vaccines.
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Ball
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.|b Faculty of Veterinary Medicine , University of Omar Al-Mukhtar , Al-Bayda , Libya.
authors.forename: Faez
authors.initials: F
authors.lastname: Awad
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Hutton
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Forrester
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.|c NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool , Liverpool , UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Baylis
authors.affiliation: a Institute of Infection and Global Health, University of Liverpool, Leahurst Campus , Cheshire , UK.
authors.forename: Kannan
authors.initials: K
authors.lastname: Ganapathy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001991:Bronchitis / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D002645:Chickens / Q000276:immunology* / Q000821:virology; D018352:Coronavirus Infections / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D014644:Genetic Variation; D001351:Infectious bronchitis virus / Q000235:genetics / Q000276:immunology*; D020641:Polymorphism, Single Nucleotide; D011201:Poultry Diseases / Q000517:prevention & control* / Q000821:virology; D016415:Sequence Alignment / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D014613:Vaccines, Attenuated; D014765:Viral Vaccines
keywords: IBV; PCR and sequencing; SNP; broiler chicks; live vaccine