Research Group for Emerging and Re-emerging Infectious Diseases in Animals and Zoonotic Diseases, Khon Kaen University, Khon Kaen 40002, Thailand; Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Research Group for Emerging and Re-emerging Infectious Diseases in Animals and Zoonotic Diseases, Khon Kaen University, Khon Kaen 40002, Thailand; Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Infect Genet Evol. 2022 Jan;97:105157. doi: 10.1016/j.meegid.2021.105157. Epub 2021 Nov 23.
The QX-like infectious bronchitis virus (IBV) and variant genotype have been discovered worldwide including Thailand. In order to know the origin of QX-like and variant genotype IBV in Thailand, the genetic analysis on multiple genes was investigated. Seven IBVs including four QX-like and three variant genotype were randomly selected from IBVs isolated in Thailand during 2008 and 2010. Phylogenetic analysis of the S2-3a/3b-E-M-4b/4c-5a/5b-N gene showed that Thai QX-like and variant genotype IBV were grouped together in a separate branch from other IBV strains. The isolated IBVs shared nucleotide identities of 96-99.9% with each other. They exhibited a high level of similarity (93.8%) with KM91 strain in South Korea. Phylogenetic analysis of the S2 and 3a/3b gene showed a relationship to KM91 strain. The E gene was distinct from other IBV strains. The M, 4a/4b and 5a/5b gene were closely related to Massachusetts type. The N gene was classified into two groups which were a group of unique to Thailand (variant genotype) and a relationship with Massachusetts type (QX-like). Recombination analysis identified the occurrence of recombination events in the genome of viruses. These findings demonstrated that the QX-like IBV and variant genotype isolates in Thailand were the recombinant viruses. Thai QX-like IBV had a genetic relationship with KM91 strain, Massachusetts type and unknown IBV whereas variant genotype had a genetic relationship with Thai QX-like IBV and Connecticut strain.
QX 样传染性支气管炎病毒（IBV）和变异基因型已在包括泰国在内的世界各地被发现。为了了解泰国 QX 样和变异基因型 IBV 的起源，对多个基因进行了遗传分析。从 2008 年和 2010 年在泰国分离的 IBV 中随机选择了 7 株 IBV，包括 4 株 QX 样和 3 株变异基因型。S2-3a/3b-E-M-4b/4c-5a/5b-N 基因的系统进化分析表明，泰国的 QX 样和变异基因型 IBV 与其他 IBV 株聚集在一个单独的分支中。分离的 IBV 彼此之间的核苷酸同一性为 96-99.9%。它们与韩国的 KM91 株具有高度相似性（93.8%）。S2 和 3a/3b 基因的系统进化分析表明与 KM91 株有关。E 基因与其他 IBV 株不同。M、4a/4b 和 5a/5b 基因与马萨诸塞型密切相关。N 基因分为两组，一组是泰国特有的（变异基因型），另一组与马萨诸塞型（QX 样）有关。重组分析确定了病毒基因组中重组事件的发生。这些发现表明，泰国的 QX 样 IBV 和变异基因型分离株是重组病毒。泰国的 QX 样 IBV 与 KM91 株、马萨诸塞型和未知的 IBV 具有遗传关系，而变异基因型与泰国的 QX 样 IBV 和康涅狄格株具有遗传关系。
