ORIGINAL RESEARCH article
Front. Cell. Infect. Microbiol.
Sec. Veterinary and Zoonotic Infection
Volume 15 - 2025 | doi: 10.3389/fcimb.2025.1640152
This article is part of the Research TopicUnveiling Host-Pathogen Interactions: Insights into Animal Cellular Immunity and Novel Diagnostics - Volume IIView all 14 articles
Dominance of the GI-19 genotype and genomic characterization of the S1 gene in avian infectious bronchitis virus from 2020 to 2024
Provisionally accepted
Xiaozhen Guo
Cunxia LiuFeng Hu
Liping LiuTong ZhuYuehua GaoZhongyin LinHuaiying Xu
Bing HuangZhuoming QinXiuli Ma*- Shandong Academy of Agricultural Sciences, Jinan, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
The continuous emergence of avian infectious bronchitis virus (IBV) variants poses a critical threat to poultry health and productivity in China. In this study, we conducted comprehensive genetic and antigenic analyses of IBV strains isolated in our laboratory between 2020 and 2024. A total of 94 IBV isolates were sequenced for the S1 gene, revealing widespread nucleotide insertions, deletions, and mutations.Phylogenetic analysis indicated that GI-19 was the predominant genotype (70.21%), followed by GI-13 (21.28%). Recombination analysis using RDP 5.42 identified 14 recombinant strains, primarily GI-13/GI-22 (50%), GI-19/GI-7 (28.6%), and GI-19/GI-22 (21.4%), which were further confirmed using Simplot. Glycosylation analysis revealed that all isolates possessed 14 to18 N-glycosylation sites, whereas only the SDJN3/23 strain contained an O-glycosylation site (position 416). Novel cleavage site motifs (HRRKR, HRHRR, RRFRR) were identified in GI-19 strains, diverging from the canonical HRRRR. The evolutionary rate calculated via BEAST software, was 1.98 × 10⁻⁴ substitutions/site/year. Serum neutralization assays demonstrated that GI-19 recombinants exhibited partial one-way cross-protection against GI-1, GI-13, and GI-22 genotypes (titer ≥ 1:32), but reciprocal neutralization was limited. Overall, we systematically characterized the genetic diversity and antigenic evolution of the currently circulating IBV strains in China, emphasizing the critical demand for genotype-specific vaccine development and dynamic surveillance systems to counteract viral immune escape.
Keywords: Avian infectious bronchitis virus, S1 gene, recombination, Evolutionary rate, cross-protection
Received: 13 Jun 2025; Accepted: 09 Jul 2025.
Copyright: © 2025 Guo, Liu, Hu, Liu, Zhu, Gao, Lin, Xu, Huang, Qin and Ma. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Xiuli Ma, Shandong Academy of Agricultural Sciences, Jinan, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.