Chen Ying, Mo Yan-Ning, Zhou Hua-Bo, Wei Zu-Zhang, Wang Guo-Jun, Yu Qing-Xiong, Xiao Xiong, Yang Wen-Juan, Huang Wei-Jian
College of Animal Science and Technology, Guangxi University, No.100 Daxue Road, Nanning, 530004, People's Republic of China.
Huabo Pet Medical Center, Yufeng District, No.342 Liushi Road, Liuzhou, 545005, People's Republic of China.
Virol J. 2015 Feb 3;12:10. doi: 10.1186/s12985-015-0243-2.
After the 1968 H3N2 pandemic emerged in humans, H3N2 influenza viruses continuously circulated and evolved in nature. An H3N2 variant was circulating in humans in the 1990s and subsequently introduced into the pig population in the 2000s. This virus gradually became the main subtype of swine influenza virus worldwide. However, there were no reports of infections in dogs with this virus.
In 2013, 35 nasal swabs from pet dogs were positive for Influenza A virus by RT-PCR. Two viruses were isolated and genetically characterized. In the phylogenetic trees of all gene segments, two H3N2 canine isolates clustered with Moscow/10/99 and most H3N2 swine influenza viruses. These results indicated that two H3N2 CIVs possessed high homology with human/swine influenza viruses, which at the same time exhibited some amino acid substitutions in NA, polymerase basic protein 1 (PB1), and nucleoprotein (NP), which probably were related to the interspecies transmission.
These two viruses share the highest homology with swine H3N2, Moscow/99-like viruses, which indicated that these viruses might originate from swine viruses.
1968年H3N2流感大流行在人类中出现后，H3N2流感病毒在自然界中持续传播和进化。一种H3N2变异株在20世纪90年代在人类中传播，随后在21世纪初传入猪群。这种病毒逐渐成为全球猪流感病毒的主要亚型。然而，尚无该病毒感染犬类的报道。
2013年，通过逆转录-聚合酶链反应（RT-PCR）检测发现，35份宠物犬鼻拭子甲型流感病毒呈阳性。分离出两种病毒并进行了基因特征分析。在所有基因片段的系统发育树中，两种H3N2犬分离株与莫斯科/10/99以及大多数H3N2猪流感病毒聚类。这些结果表明，两种H3N2犬流感病毒（CIV）与人类/猪流感病毒具有高度同源性，同时在神经氨酸酶（NA）、聚合酶碱性蛋白1（PB1）和核蛋白（NP）中表现出一些氨基酸替换，这可能与种间传播有关。
这两种病毒与猪H3N2、莫斯科/99样病毒具有最高同源性，表明这些病毒可能起源于猪病毒。
