Re‐emergence of a genotypeVIIIvirulent Newcastle disease virus isolated from Chinese game fowl after 13 years

Abstract

Circulation of dominant genotypes VI and VII of Newcastle disease virus (NDV) is causing significant economic losses to the poultry industry in China. However, reports of Newcastle disease (ND) outbreaks caused by genotype VIII strains of NDV are rare. In this study, a virulent genotype VIII strain of NDV, designated GXGB2011, was isolated from a vaccinated game fowl flock showing clinic signs of infection in Pinxiang county, Guangxi, China. The whole genome of the isolate was completely sequenced and was found to be comprised of 15,192 nucleotides (nt), encoding the six structural proteins in the order of 3′‐NP‐P‐M‐F‐HN‐L‐5′. The pattern of cleavage site 112RRQKR↓F117 in the fusion (F) protein and the intracerebral pathogenicity index (ICPI) value of 1.5 showed that the strain GXGB2011 was a velogenic NDV. The results of the challenge experiment with the 5‐week‐old SPF chickens showed that the strain was highly pathogenic with 100% morbidity and mortality of the challenged birds. Based on the detection of virus in different organs of the infected birds, the highest viral load in caecal tonsils was observed and viral levels in immune organs were higher than those in the respiratory organs. Bayesian reconstruction of complete genomes based on the sequences of 66 NDV reference strains showed that the strain belonged to the genotype VIII of NDV. Phylogenetic analysis showed that the strain was more closely related to the foreign strains gamefowl/U.S.(CA)/24225/98, 1ITTY94060 and IT‐147/94 rather than to the first domestic strains of the emergence genotype VIII in Qinghai, China during 1979–1985. In summary, the results of the study demonstrated the re‐emergence of a highly pathogenic virulent isolate of genotype VIII of NDV. These results indicate the risk that this genotype VIII of NDV may spread to commercial chickens from game fowl.

Genetic Analysis of Avian Coronavirus Infectious Bronchitis Virus in Yellow Chickens in Southern China over the Past Decade: Revealing the Changes of Genetic Diversity, Dominant Genotypes, and Selection Pressure

“…Statistical uncertainty (reflected calculating 95% high probability density (HPD) values) and convergence (reflected calculating effective sample size) in parameter estimates were evaluated in Tracer version 1.5 program. The posterior sets of trees were summarized as a maximum clade credibility (MCC) tree using Tree Annotator version 1.8.2 with 10% burn-in and then displayed the created MCC tree using FigTree version l.4.3 [40]. The mutation rates and the most recent common ancestor (tMRCA) of the aligned sequences were estimated.…”

A novel recombinant avian leukosis virus isolated from gamecocks induced pathogenicity in Three-Yellow chickens: a potential infection source of avian leukosis virus to the commercial chickens

“…The Guangxi gamecock is a rare bird known for its good fighting ability, competition, and entertainment value. About 80,000 gamecocks per year were sold to other parts of Guangxi and other provinces in China like Guizhou, Henan, Anhui, Xinjiang (Wei et al, 2019).…”

Insights into Genomic Epidemiology, Evolution, and Transmission Dynamics of Genotype VII of Class II Newcastle Disease Virus in China

“…Since the isolation of the first genotype VII NDV strain in China in 1995, this genotype has gradually become the predominant NDV genotype in China [ 10 , 36 , 37 , 38 ]. Meanwhile, some virulent NDV in genotype III, VIII, IX, and XII were also sporadically identified in China [ 12 , 13 , 17 ]. The genotype VI virulent viruses mainly circulated in pigeons [ 39 , 40 , 41 ].…”

“…In China, the genotype VII NDVs were dominant circulating genotype, contributing to most ND outbreaks in poultry, while VIII, IX, and XII virulent NDVs were also occasionally reported [ 12 , 13 , 14 ]. Of note, the genotype VI virulent NDVs, referred to pigeon paramyxovirus type 1, also identified in China, inducing disease in pigeons, but show nonvirulence to chicken [ 15 , 16 ].…”