College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Vet Microbiol. 2012 Aug 17;158(3-4):247-58. doi: 10.1016/j.vetmic.2012.02.016. Epub 2012 Feb 17.
The newly emerging canine influenza virus (CIV) causes considerable concerns for both veterinary and public health. During 2009-2010, six strains of H3N2 influenza virus were isolated from dogs in Jiangsu Province, China. Sequence and phylogenetic analysis of eight gene segments revealed that the six viruses were most similar to a recent canine-derived subtype H3N2 influenza virus isolated in cats from South Korea, which originated from avian strain. By comparing the deduced amino acid sequences of the hemagglutinin 1 (HA1) and neuraminidase (NA) genes of the six Jiangsu isolates against the most similar avian strains, we found that all isolates had several common mutations at the receptor-binding sites, potential glycosylation sites and cleavage site in HA1, and antigenic sites in both the HA1 and NA segments. Significantly, a unique two amino acid insertion in the NA stalk was found. Experimental infection of BALB/c mice revealed that viral RNA could be detected in the major rodent organs, such as brain, heart, spleen, kidney, liver and intestine, as well as the lung. All the sampled organs from infected mice showed significant lesions and viral antigen staining. This study highlights the potential of domesticated animals to become a reservoir for influenza virus and the need for surveillance programs to detect cross-species transmission.
新兴的犬流感病毒 (CIV) 引起了兽医和公共卫生界的极大关注。2009-2010 年，从中国江苏省的犬只中分离到了六株 H3N2 流感病毒。对八个基因片段的序列和系统进化分析表明，这六种病毒与最近从韩国猫中分离到的犬源 H3N2 亚型流感病毒最为相似，该病毒来源于禽源株。通过比较这六种江苏分离株的血凝素 1 (HA1) 和神经氨酸酶 (NA) 基因的推导氨基酸序列与最相似的禽株，我们发现所有分离株在 HA1 的受体结合位点、潜在糖基化位点和裂解位点以及 HA1 和 NA 片段中的抗原位点都有几个共同的突变。值得注意的是，在 NA 茎部发现了一个独特的两个氨基酸插入。BALB/c 小鼠的实验感染表明，病毒 RNA 可在主要啮齿动物器官如脑、心、脾、肾、肝和肠中检测到，以及肺。从感染小鼠中采样的所有器官均显示出明显的病变和病毒抗原染色。本研究强调了家养动物成为流感病毒储存库的可能性，以及需要监测计划来检测跨物种传播。
