Nationwide Survey of Infectious Bronchitis Virus on Layer Farms in Japan During 2015

Seventeen isolates of infectious bronchitis virus (IBV) were obtained from various prefectures of Japan during 2008–2019 and genetically analyzed. The IBV isolates were classified into six genetic groups, based on phylogenetic analysis of the S1 gene. The S1 genotypes were distinguishable by a newly developed restriction fragment length polymorphism (RFLP) method using three endonucleases, Hae II, Hpa I, and Fok I. Moreover, the isolates were classified into four genetic groups, based on phylogenetic analysis of the S2 gene. However, novel genetic groups based on a combination of S1 and S2 genotypes, which were undetected previously, were confirmed in this study, indicating that various recombinant IBV strains were prevalent in poultry in Japan.

supporting

confidence: 84%

mentioning

confidence: 69%

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Genotyping of infectious bronchitis viruses isolated in Japan during 2008−2019

Mase

Gotou

Inoue

et al. 2021

“…established RT-PCR for genotyping Japanese IBV strains based on S1 gene analysis, which enabled identification of seven genotypes (JP-I, JP-II, JP-III, JP-IV, Mass, Gray, and 4/91) [ 15 , 17 , 18 ]. The method developed by Mase et al has been used for molecular surveys of IBV in Japan by several groups [ 7 , 9 , 10 ], and the utility of the method for selection of appropriate vaccines against IB in Japan has been demonstrated. Kaneda et al .…”

mentioning

confidence: 99%

“…Kaneda et al . recently reported the results of a nationwide survey for IBV in Japan by using Mase’s method [ 9 ]; however, there was a lack of information on the prevalence of IBV in Gifu Prefecture, which is part of the Chubu area of Japan. So far, there has been little information of the prevalence of IBV in Chubu and Kinki areas in Japan.…”

mentioning

confidence: 99%

Molecular survey of infectious bronchitis virus on poultry farms in Gifu Prefecture, Japan from 2021 to 2022 by RT-PCR with an enhanced level of detection sensitivity for the S1 gene

Saito¹,

Nakagawa

Kitamura³

et al. 2022

Infectious bronchitis virus (IBV) is the causative agent of infectious bronchitis (IB) in chickens. There is a correlation between cross-protection and percentage of similarity between nucleotide sequences encoding the S1 subunit, which is responsible for generating neutralizing and serotype-specific antibodies. Therefore, RT-PCR is commonly used to amplify the IBV-S1 gene following DNA sequencing in order to predict the efficacy of vaccines against IBV strains. We successfully enhanced the sensitivity for detection of the IBV-S1 gene by second PCR after purification of the 1st RT-PCR product. Using that method, we obtained detailed information on the prevalence of IBV on poultry farms in Gifu Prefecture, Japan. The IBV-S1 gene detection method used in the current study will enable accurate information on the prevalence of IBV in Japan to be obtained.

Detection and isolation of QX-like infectious bronchitis virus in Japan

Nakanishi

Soma

Takahashi

et al. 2022

Self Cite

The antigenic variant QX-like infectious bronchitis virus (IBV) is endemic in several countries. In Japan, the QX-like genotype is classified as the JP-III genotype based on the partial S1 gene and as the GI-19 genotype based on the complete S1 gene. This study showed that QX-like IBVs and JP-III IBVs can be identified based on the amino acid polymorphism of the S1 glycoprotein. Furthermore, genetic analysis of several IBV field strains detected in commercial broiler farms across the Kyushu area in 2020 revealed Japanese QX-like IBVs, which are highly homologous to the QX-like IBVs recently detected in China and South Korea. Herein, QX-like IBV field strains were isolated for evaluating commercial vaccine efficacy in our future studies.