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

Abstract

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.

Spike Glycoprotein 1 Partial Gene Analysis of GI-19 (QX-like) Infectious Bronchitis Virus Isolated and Propagated from Breeder, Broiler, and Layer Chickens in Java Region

“…Interestingly, QX strain infection is not always related to reprodutive symptoms; in fact, we found respiratory symptoms in breeder caused by QX-like (MHW/IBV/BF3/2021). then QX strains by Nakanishi et al (2022) and in this study. The variation in amplified strains was due to the fact that the primer design has been adjusted to the nucleotide composition in the annealing site of the primer and has been predicted previously with BLAST (Figure 1).…”

“…In this research, we examined the partial S1 in the N-terminus region, where receptor binding sites (RBS) and antigenic sites (HVR-I and II) could be found. The same region has also been studied by previous researchers (Shimazaki et al 2008;Parvin et al 2021;Nakanishi et al 2022). Interstingly, Parvin et al (2021) proved that the same isolates (Mass-like, 4/91-like, and QX-like from Bangladesh) were in a consistent group when examined with 2 different primers: the first was HVR-I and II primer (Adhzar et al 1997), and the second was HVR-III primer (Naguib et al 2017).…”

Key Aspects of Coronavirus Avian Infectious Bronchitis Virus

“…The GI-13 (793B-type) was detected most frequently in Europe, followed by GI-19 (QX-type) and GI-1 (Mass-type). In Asia, including Japan, Korea, India, Indonesia, Thailand, and China, QX-type (GI-19) strains are the most prevalent and exist in all six countries; 793B-type (GI-13) is the second popular lineage that exists in five countries except Korea; Mass-type (GI-1) strains are also isolated in India, Indonesia, Thailand, and China [ 22 , 23 , 24 , 34 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 48 ]. In addition, many other strains (lineages) are found in several countries, such as lineage GⅥ-1 (TC07-2) in Korea and China, Variant IBV (GI-24) in India, D85/06 (GI-15) in Korea, Taiwan-I (GI-7) in China, CU-92 (Novel variant) in Thailand, and Gray (GI-3), JP- I (GI-18) and JP-Ⅱ (GI-7) in Japan [ 8 , 22 , 34 , 44 , 46 , 48 , 53 ].…”

Evaluation of the efficacy of commercial live vaccines against the local Thai QX field strain for the protection of specific pathogen-free chicks

“…Among the 1652 IBV strains used for IBV nomenclature, the QX virus with the most significant number (33.0%) was collected and classified under the new nomenclature as the GI-19 lineage [ 7 ]. Numerous reports have described the prominent QX-like strain in avian IB globally, including China [ 8 ], Japan [ 9 ], South Korea [ 10 ], Europe [ 11 ], the Middle East [ 12 ], and various African countries [ 13 , 14 ]. The QX-like IBV outbreak in Thai broiler flocks was first documented in 2009 [ 15 ].…”