title: Pathotypic and Sequence Characterization of Newcastle Disease Viruses from Vaccinated Chickens Reveals Circulation of Genotype II, IV and XIII and in India.
abstract: Newcastle disease virus (NDV) causes a highly contagious disease which continuously haunts the global poultry industry. The nature and molecular epidemiology of NDVs prevalent in recent outbreaks in India is poorly understood. This study aimed to characterize NDVs prevalent in vaccinated flocks in India using whole-genome sequencing and biological pathotyping. Twelve field isolates were collected from outbreaks which occurred in different parts of India and characterized as velogenic based on their intracerebral pathogenicity index (ICPI) and amino acid sequence at the F protein cleavage site. All 12 of the field isolates and five commonly used vaccine strains were selected for whole-genome sequencing using Ion Torrent PGM technology, yielding complete genome sequences for ten field isolates and all vaccine strains. The genome of all isolates was found to be 15 192 nt long with a high level of conservation across multiple genomic features with APMV-I viruses. Phylogenetic analysis and evolutionary distance calculations placed the isolates in genotypes II, IV and XIII. Revisiting other recently reported strains provided preliminary evidence of genotypes VI, VII and XVIII circulating in India. Comparison between the field and vaccine virus sequences revealed unique genomic and amino acid differences in important antigenic regions of the F and hemagglutinin-neuraminidase (HN) genes which can be targeted for site directed mutagenesis to evaluate the impact of these substitutions on virus pathogenicity. This study highlights the requirement to evaluate current vaccines through systematic protection assays to determine protection efficacy against field isolates.
authors.affiliation: Department of Animal Biotechnology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, India.
authors.forename: S J
authors.initials: SJ
authors.lastname: Jakhesara
authors.affiliation: Hester Biosciences Limited, Mehsana, Gujarat, India.
authors.forename: V V S P
authors.initials: VV
authors.lastname: Prasad
authors.affiliation: Hester Biosciences Limited, Mehsana, Gujarat, India.
authors.forename: J K
authors.initials: JK
authors.lastname: Pal
authors.affiliation: Department of Veterinary Microbiology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Jhala
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Prajapati
authors.affiliation: Department of Animal Biotechnology, College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand, Gujarat, India.
authors.forename: C G
authors.initials: CG
authors.lastname: Joshi
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D014644:Genetic Variation; D005838:Genotype; D007194:India; D009521:Newcastle Disease / Q000821:virology; D009522:Newcastle disease virus / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014765:Viral Vaccines
chemical_list: D014765:Viral Vaccines
keywords: ion torrent PGM; newcastle disease; phylogeny; vaccine; whole-genome sequencing