Phylogenetic analysis of the S1 glycoprotein gene of infectious bronchitis viruses isolated in China during 2009–2010

Abstract

As part of our ongoing surveillance program, 40 field strains of avian infectious bronchitis virus (IBV) were isolated from dead or diseased chicken flocks in different areas of China between 2009 and 2010. S1 glycoprotein genes of these strains were sequenced and analyzed with 38 strains published in GenBank. S1 genes of these isolated strains and the vaccine strains showed nucleotide homologies ranging from 65.2 to 82% and amino acid homologies ranging from 58.4 to 81.9%. Meanwhile, Chinese IBV strains isolated in this study, which were mainly nephropathogenic, could be separated into six variant lineages (CH I-CH VI), and current vaccine strains used in China formed Mass variant lineage that is evolutionarily distant from Chinese isolates. Moreover, CK/CH/GD/NC10, CK/CH/GD/KP10, and our previous isolates TC07-2 formed the CH VI lineage, showing larger evolutionary distances from other strains. Taken together, these findings suggested that various variant lineages were co-circulating in China now, and appeared to be continuously evolving, alternative indigenous vaccines indeed need for effective control of IB in China.

Identification of a novel recombinant virulent avian infectious bronchitis virus

“…This study identified an IBV, CK/CH/2010/JT-1, and 31 other isolates grouped into a novel genotypic cluster different from previously identified genotypes. Although 23 of the 31 isolates were reported in other five papers, we found that among the 23 isolates, 13 isolates were clustered into a genotype with reference strains A2 and QXIBV (Luo et al, 2012), 9 isolates were grouped with reference strains 4/91 and UK 7/93 (Feng et al, 2014;Ji et al, 2011;Li et al, 2010), and one isolate showed far evolutionary distances with reference tl/CH/LDT3/03 strains, but grouped into tl/CH/LDT3/03-type . In our study, the CK/CH/2010/JT-1 and 31 strains showed a low S1 nucleic acid identity with reference strains.…”

Identification and molecular characterization of a novel serotype infectious bronchitis virus (GI-28) in China

“…The closest relative genotype was IBV LX4, the most predominant variant in China , which shared approximately 87% nucleotide and amino acid identities with isolate ck/CH/LGX/ 111119. There are several publications of the IBV genotype that included ck/CH/LGX/111119, but unfortunately these reports do not agree on genotype designations, such as A2 by Ji et al (2011) and CH III by Luo et al (2012) and Feng et al (2014). Also, the virus genotype designations were inconsistent even in reports by the same research group (Ji et al, 2011;Feng et al, 2014).…”

Altered pathogenicity of a tl/CH/LDT3/03 genotype infectious bronchitis coronavirus due to natural recombination in the 5′- 17 kb region of the genome

“…The tl/CH/LDT3/03 strain was first isolated in 2003 in Guangdong province, China (Liu et al, 2005), which was close to Guangxi province where ck/CH/LGX/130530 was isolated. The tl/CH/LDT3/03-like viruses were also isolated and shown to be one of the major types of viruses circulating in H120-vaccinated chicken flocks in southern China, including Guangxi province, in recent years (Luo et al, 2012;Feng et al, 2014). The company at which ck/CH/LGX/130530 was isolated had more than a 20-year history of chicken breeding, and it had used the H120 vaccine against IBV for more than 15 years.…”