Li Jiqing, Deng Guohua, Shi Jianzhong, Zhang Yaping, Zeng Xianying, Tian Guobin, Jiang Yongping, Liu Liling, Kong Huihui, Chen Hualan
State Key Laboratory of Animal Disease Control and Prevention, Harbin Veterinary Research Institute, CAAS, Harbin, China.
Transbound Emerg Dis. 2023 Jul 26;2023:8834913. doi: 10.1155/2023/8834913. eCollection 2023.
H3N2 influenza viruses not only cause seasonal epidemics in humans but also circulate widely in animals, posing a threat to both animal and human health. Our previous studies indicate that H3N2 avian influenza viruses (AIVs) are readily detected in live poultry markets (LPMs); however, the evolution and biological characteristics of the H3N2 viruses in poultry farms in China are unclear. In this study, we performed active surveillance and collected 49,135 samples from poultry farms. In total, 21 H3N2 AIVs were isolated and their genetics, receptor-binding properties, and replication in mice were evaluated. Phylogenetic analysis indicated that H3N2 AIVs harbor complicated gene constellations and have undergone extensive reassortment; the viruses derived their genes from 12 different hemagglutinin subtypes of duck viruses, including H1, H2, H4, H5, H6, H7, H8, H9, H10, H11, H12, and H14. The complicated gene constellations indicated that H3N2 viruses may have been introduced into poultry farms from different sources, but none have become dominant in poultry farms. Although the H3N2 AIVs possessed avian-type receptor-binding preference, most of the isolates could replicate without preadaptation and some of H3N2 viruses caused weight loss in mice. Notably, two H3N2 viruses acquired the PB2 627K mutation after a single round of replication in mice, suggesting similar mutations could occur if they replicated in humans. Overall, our study demonstrates that the H3N2 AIVs pose a potential threat to the public health and emphasizes the need for continued surveillance of H3N2 viruses in the both LPMs and poultry farms.
H3N2流感病毒不仅会引发人类季节性流行病，还会在动物中广泛传播，对动物和人类健康均构成威胁。我们之前的研究表明，H3N2禽流感病毒（AIV）很容易在活禽市场（LPM）中被检测到；然而，中国家禽养殖场中H3N2病毒的进化和生物学特性尚不清楚。在本研究中，我们进行了主动监测，并从家禽养殖场收集了49135份样本。总共分离出21株H3N2 AIV，并对其遗传学、受体结合特性及在小鼠体内的复制情况进行了评估。系统发育分析表明，H3N2 AIV具有复杂的基因组合，并经历了广泛的重配；这些病毒的基因来源于鸭病毒的12种不同血凝素亚型，包括H1、H2、H4、H5、H6、H7、H8、H9、H10、H11、H12和H14。复杂的基因组合表明，H3N2病毒可能从不同来源引入家禽养殖场，但在养殖场中均未占据主导地位。尽管H3N2 AIV具有禽源型受体结合偏好，但大多数分离株无需预先适应就能复制，且部分H3N2病毒会导致小鼠体重减轻。值得注意的是，两株H3N2病毒在小鼠体内经过一轮复制后获得了PB2 627K突变，这表明如果它们在人体内复制，可能会发生类似的突变。总体而言，我们的研究表明H3N2 AIV对公众健康构成潜在威胁，并强调需要继续对活禽市场和家禽养殖场中的H3N2病毒进行监测。
