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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #411916
Research Project: Intervention Strategies to Predict, Prevent, and Control Emerging Strains of Virulent Newcastle Disease Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: Genetic analysis of low pathogenic Newcastle disease virus (loNDVs) isolated from wild birds during adaptation to chicken embryos

Author
item CHAUDHARY, DEEPA - Auburn University
item FARJANA, SAIADA - Auburn University
item PEDROZA, STEPHEN - Auburn University
item PIETRUSKA, ANDREA - Auburn University
item KYRIAKIS, CONSTANTINOS - Auburn University
item Suarez, David
item Lee, Chang
item HAUCK, RUEDIGER - Auburn University

Submitted to: Western Poultry Disease Conference
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Newcastle disease, caused by the Newcastle disease virus (NDV) is one of the most economically important diseases for poultry production worldwide. The periodic occurrence of NDV vaccine strains in wild birds in North America indicates that transmission from domestic birds to wild birds is possible. NDV may also be transmitted back from wild birds to chickens. This study investigated the adaptation of NDV strains from aquatic to the chicken as host and if that might cause an increase in virulence for chickens. Six isolates of low-pathogenic Newcastle disease virus (loNDV) isolated from wild aquatic birds were passaged in chicken embryos for ten passages. The virulence of the first and the last passage of each isolate was compared by embryo mean death time (EMDT). The whole genomes of the first and tenth passages were sequenced using Illumina. For each isolate, the genome of passage 1 was assembled de novo and the reads of passage 10 were aligned with the passage 1 genome for variant calling. Variant functional consequences were predicted using the Ensembl VEP software. Phylogenetic analysis was done to determine evolutionary relationships among isolates. The phylogenetic trees, based on complete genome sequences, were performed using the neighbor-joining method with 1000 bootstraps in MEGA software. There were only minor differences between EMDT of the first and tenth passage with no recognizable trend. Sequences covering the full genome sequences >15 kbp in length were obtained from both passages of all six isolates. The mean sequencing depths were between 95 and 480. Preliminary analysis showed that close to 300 single nucleotide polymorphisms (SNPs) and almost 20 INDELs were present in all isolates. The number of SNPs was between 34 and 71 in each isolate and the number of INDELs between 1 and 6 in each isolate. Phylogenetic analysis of the whole genomes identified isolates 5, and 8 among the Class I NDV and isolates 6, 7, 9, and 10 among the Class II NDV. This study demonstrates how loNDVs from aquatic birds adapt to chickens as host. These identified variants are likely to play a role in the adaptation to chicken embryos, however, there is no indication that the virulence for chickens increased.