Genetic and pathogenic characterization of a novel recombinant avian infectious bronchitis virus derived from GI-1, GI-13, GI-28, and GI-19 strains in Southwestern China

Poultry Science

Chun Li¹  Changwei Lei¹  Rongbin Qiu¹  Pengfei Cui¹  Kui Gu¹  Hao Li²  Lei Zuo²  Lan Zhang²  Xin Yang²  Wenjun Yan²  Yaru Zhai²  Fuyan Wang³  Hongning Wang⁴  Xue Fu⁵ 

[1] Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science Sichuan University, Chengdu 610064, China;Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province;College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China;Sichuan Animal Disease Control Center, Chengdu, 610041, China;Sichuan Sundaily Farm Ecological Food Co., Ltd., Mianyang 621010, China;

关键词: infectious bronchitis virus;    recombination;    pathogenicity;   

DOI  :  

来源: DOAJ

【 摘 要 】

ABSTRACT: Avian infectious bronchitis (IB), caused by avian infectious bronchitis virus (IBV), is an acute and highly contagious disease that is extremely harmful to the poultry industry throughout the world. The cross-using of different attenuated live vaccine strains has led to the occurrence of diverse IBV serotypes. In this study, we isolated an IBV strain from a chicken farm in southwest China and designated it CK/CH/SCMY/160315. Construction of a phylogenetic tree based on full S1 gene sequence analysis suggested that CK/CH/SCMY/160315 bears similarity to GI-28, and further comparison of S1 amino acid residues revealed that CK/CH/SCMY/160315 showed mutations and deletions in many key positions between LDT3-A and other GI-28 reference strains. Importantly, CK/CH/SCMY/160315 was identified as a novel recombinant virus derived from live attenuated vaccine strains H120 (GI-1), 4/91 (GI-13), LDT3-A (GI-28), and the field strain LJL/08-1 (GI-19), identifying at least 5 recombination sites in both structural and accessory genes. Pathogenicity analysis indicated that CK/CH/SCMY/160315 caused listlessness, sneezing, huddling, head shaking, and increased antibody levels in the inoculated chickens. To further describe pathogenicity of this novel strain, we assessed viral load in different tissues and conducted hematoxylin and eosin (HE) staining of the trachea, lungs and kidneys. Our results provide evidence for the continuing evolution of IBV field strains via genetic recombination and mutation, leading to outbreaks in the vaccinated chicken populations in China.

【 授权许可】

Unknown