Molecular and biological characterization of some circulating strains of Newcastle disease virus in broiler chickens from Eastern Saudi Arabia in 2012-2014

Abstract

Background and Aim: Newcastle disease (ND) is a worldwide poultry disease that is historically known to cause severe losses in the poultry industry. In the present study, attempts were made to characterize ND virus (NDV) recovered from broiler chickens in the Eastern Region of Saudi Arabia from January 2012 to March 2014. Materials and Methods: Reverse transcription-polymerase chain reaction was used for the detection of NDV followed by partial sequencing of the fusion (F) gene. The intracerebral pathogenicity index (ICPI), mean death time (MDT), and complete sequencing of the hemagglutinin-neuraminidase (HN) gene were also used for further biological and molecular characterization. Results: NDV was detected at a rate of 9.6% (11/115) of the tested flocks, most of which were vaccinated against ND. F gene-based phylogeny and motifs of the fusion protein cleavage site (FPCS) showed segregation of Saudi isolates into two groups. The first group contained 10 isolates and was located in genotype II with the lentogenic motif 112GRQGRL117 at the FPCS. The second group contained one isolate and was located in genotype VII with velogenic motif 112RRQKRF117. Further characterization using the ICPI and MDT of two representative isolates showed virulence of both tested isolates. Phylogenetic analysis of the HN gene showed close nucleotide identity between the two isolates. A BLAST search for sequences similar to HN gene sequences showed high identity with isolates from the surrounding region. Conclusion: The present findings showed a low detection rate of NDV, possibly due to the wide application of vaccines, and the circulation of at least two NDV genotypes, II and VII, in the Eastern Region of Saudi Arabia. The present Saudi isolates may share common ancestors with isolates from the surrounding region.

Novel variant infectious bursal disease virus suppresses Newcastle disease vaccination in broiler and layer chickens

“…It is well known that vaccination plays a significant role in the control of ND, especially in large-scale intensive chicken farms. However, it has been observed that ND sometimes occurred in some vaccinated poultry farms in recent years ( Mariappan et al., 2018 ; Almubarak, 2019 ). On the one hand, a few NDV strains were reported as novel subgroups and genotype mismatches ( Le et al., 2018 ; Gowthaman et al., 2019 ; Liu et al., 2019 ).…”

A Review of Current Knowledge on Avian Newcastle Infection in Commercial Poultry in the Kingdome of Saudi Arabia

“…Newcastle disease has significantly affected Saudi Arabia’s commercial chicken production. Poultry producers have experienced significant financial losses due to outbreaks, decreased egg production and higher death rates ( Almubarak, 2019 ). These ramifications influence food security and the accessibility of poultry goods on the local market in addition to the poultry industry’s financial viability.…”

“…An investigation into the function of NDV in this context was conducted in the Eastern Region of Saudi Arabia between 2012 and 2014. In order to provide light on the dynamics of the disease in the area, this survey attempted to describe the circulating NDV strains ( Almubarak, 2019 ).…”

“…This spectrum allows the strains to be identified from one another. The potential for velogenic strains to generate catastrophic outbreaks with significant mortality rates in poultry populations makes them particularly concerning among these pathogens ( Almubarak, 2019 )…”

“…ND has continued to pose a concern to Saudi Arabia, with isolated outbreaks happening in various parts of the country ( El-Zein, 1986 ; Al-Ali et al , 2018 ; Almubarak, 2019 ). These outbreaks, which can be moderate to severe, can wipe out whole poultry flocks, including turkeys and chickens.…”