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Abstract：
H9N2 avian influenza viruses (AIVs) affect both poultry and humans on a global level, and they are especially prevalent in Egypt. In this study, we sequenced the entire genome of AIV H9N2 isolated from chickens in Egypt in 2021, using next-generation sequencing (NGS) technology. Phylogenetic analysis of the resulting sequences showed that the studied strain was generally monophyletic and grouped within the G1 sublineage of the Eurasian lineage. Four segments (polymerase basic 2 [PB2], polymerase basic 1 [PB1], polymerase acidic [PA], and non-structural [NS]) were related to Egyptian genotype II, while the nucleoprotein (NP), neuraminidase (NA), matrix (M), and haemagglutinin (HA) segments were related to Egyptian genotype I. Molecular analysis revealed that HA protein contained amino acid residues (191H and 234L) that suggested a predilection for attaching to human-like receptors. The antigenic sites of HA had two nonsynonymous mutations: V194I at antigenic site A and M40K at antigenic site B. Furthermore, the R403W and S372A mutations, which have been observed in H3N2 and H2N2 strains that caused human pandemics, were found in the NA protein of the detected strain. The internal proteins contained virulence markers: 504V in the PB2 protein, 622G, 436Y, 207K, and 677T in the PB1 protein, 127V, 550L, and 672L in PA protein, and 64F and 69P in the M protein. These results show that the detected strain had undergone intrasubtype reassortment. Furthermore, it contains changes in the viral proteins that make it more likely to be virulent, raising a question about the tendency of AIV H9N2 to become highly pathogenic in the future for both poultry and humans.
摘要：
H9N2禽流感病毒（AIV）在全球范围内影响家禽和人类，它们在埃及尤其普遍。在这项研究中,我们于2021年使用下一代测序（NGS）技术对从埃及鸡分离的AIVH9N2的整个基因组进行了测序。对所得序列的系统发育分析表明，所研究的菌株通常是单系的，并归入欧亚谱系的G1亚谱系。四个片段(聚合酶碱性2[PB2]，聚合酶碱性1[PB1]，聚合酶酸性[PA]，和非结构[NS]）与埃及基因型II有关，而核蛋白（NP），神经氨酸酶（NA），矩阵(M)，和血凝素（HA）片段与埃及基因型I有关。分子分析表明，HA蛋白含有氨基酸残基（191H和234L），这表明倾向于附着于类似人的受体。HA的抗原位点具有两个非同义突变:在抗原位点A处的V194I和在抗原位点B处的M40K。R403W和S372A突变，在引起人类大流行的H3N2和H2N2菌株中观察到，在检测到的菌株的NA蛋白中发现。内部蛋白含有毒力标记：PB2蛋白中的504V，622G,436Y,207K,和677T在PB1蛋白中，127V,550L,和672L的PA蛋白，和M蛋白中的64F和69P。这些结果表明检测到的菌株经历了B型内重排。此外，它包含病毒蛋白质的变化，使其更有可能具有毒性，提出了一个关于AIVH9N2将来对家禽和人类都具有高致病性的趋势的问题。
