Molecular characterization of full genome sequences of Newcastle disease viruses circulating among vaccinated chickens in Egypt during 2011–2013
| Autor: | Kunitoshi Imai, Hieu Van Dong, Mohamed Ismail Hassan, Haruko Ogawa, Giang Thi Huong Tran, Yukie Katayama, Serageldeen Sultan, Tsutomu Omatsu, Tung Duy Dao, Nabila Osman, Tetsuya Mizutani, Yohei Takeda |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
vaccinated chicken
animal structures Genotype VII.1.1 Newcastle Disease animal diseases Newcastle disease virus Virulence Genome Viral Newcastle disease Virus Epitopes Virology Animals Genotyping Phylogeny Poultry Diseases Full Paper General Veterinary biology Vaccination High-Throughput Nucleotide Sequencing Outbreak Viral Vaccines biology.organism_classification genotyping Egypt Flock Chickens |
| Zdroj: | The Journal of Veterinary Medical Science |
| ISSN: | 1347-7439 0916-7250 |
| DOI: | 10.1292/jvms.19-0623 |
| Popis: | Although intensive vaccination programs have been implemented, Newcastle disease (ND) outbreaks, accompanied by severe economic losses, are still reported in Egypt. The genetic characterization of ND virus (NDV) strains isolated from ND-vaccinated chicken flocks provides essential information for improving ND control strategies. Therefore, here, 38 NDV strains were isolated and identified from outbreaks among vaccinated flocks of broiler chickens located in the provinces of Qena, Luxor, and Aswan of Upper Egypt during 2011-2013. The investigated broiler chicken flocks (aged 28 to 40 days) had high mortality rates of up to 80%. All NDV isolates were genetically analyzed using next-generation DNA sequencing. From these isolates, 10 representative NDV strains were selected for further genetic analyses. Phylogenetic analysis of full-length coding genes revealed that the Egyptian NDV isolates belonged to a single sub-genotype, VII.1.1. These isolates were phylogenetically distant from the vaccine strains, including La Sota or Clone 30 (genotype II), which have been commonly used to vaccinate chicken flocks. Amino acid substitution K78R was observed in the neutralizing epitopes of the F proteins; whereas several mutations were found in the neutralizing epitopes of the hemagglutinin-neuraminidase proteins, notably, E347K. Overall, our results suggested that the occurrence of neutralizing epitope variants may be one of potential reasons for ND outbreaks. Further studies are needed to determine the protective effect of current vaccines against circulating virulent NDV strains. |
| Databáze: | OpenAIRE |
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