Zhongshan Center for Disease Control and Prevention, Zhongshan, Guangdong Province, PR China; Zhongshan Institute of School of Public Health, Zhongshan, Guangdong Province, PR China.
Zhongshan Center for Disease Control and Prevention, Zhongshan, Guangdong Province, PR China; Zhongshan Institute of School of Public Health, Zhongshan, Guangdong Province, PR China.
Infect Genet Evol. 2018 Jun;60:191-196. doi: 10.1016/j.meegid.2018.01.009. Epub 2018 Jan 10.
To study the molecular characteristics of H9N2-subtype avian influenza viruses (AIVs) isolated from air samples collected in live poultry markets (LPMs) and explore their sequence identities with AIVs that caused human infection.
Weekly surveillance of H9N2-subtype AIVs in the air of LPMs was conducted from 2015 to 2016. H9-positive samples were isolated from chicken embryos. Whole genome sequences of the isolated AIVs were obtained through high-throughput sequencing. Phylogenetic analysis and key loci variations of the sequences were further analyzed.
A total of 327 aerosol samples were collected from LPMs. Nine samples were positive for H9-subtype AIVs based on quantitative real-time reverse transcription polymerase chain reaction (qRRT-PCR). According to the whole genome sequence analysis and phylogenetic analysis, except for the A/Environment/Zhongshan/ZS201505/2015 (ZS201505) strain, 8 gene segments of 8 aerosol H9N2 isolates and 2 H9N2 human isolates in 2015 were located in the same clade. Among key loci variations, except for the ZS201505 strain, H9N2-subtype AIVs had no mutations in eight receptor binding sites of hemagglutinin (HA), and stalks of neuraminidase (NA) proteins exhibited a deletion site of three bases. The PA gene of ZS201503 and ZS201602 exhibited an L336M mutation. The N30D and T215A mutations in the M1 gene and amino acid residues L89V in PB2, P42S in NS1 and S31N in M2 were retained in these 9 strains of H9N2 isolates, which could enhance the virus's virulence.
Live H9N2 AIVs survived in the aerosol of LPMs in Zhongshan City. The aerosol viruses had a close evolutionary relationship with human epidemic strains, indicating that there might be a risk of AIV transmission from polluted aerosols in LPMs to humans. Mutations in H9N2-subtype AIVs isolated from air samples collected from LPMs suggested their pathogenicity was enhanced to infect humans.
研究从活禽市场（LPM）采集的空气样本中分离出的 H9N2 亚型禽流感病毒（AIV）的分子特征，并探讨其与引起人类感染的 AIV 的序列同一性。
2015 年至 2016 年期间，每周对 LPM 空气中的 H9N2 亚型 AIV 进行监测。从鸡胚中分离出 H9 阳性样本。通过高通量测序获得分离的 AIV 的全基因组序列。进一步分析序列的系统发育分析和关键基因座变异。
共采集 LPM 气溶胶样本 327 份。根据定量实时逆转录聚合酶链反应（qRRT-PCR），9 份样本检测出 H9 亚型 AIV 阳性。根据全基因组序列分析和系统发育分析，除 A/Environment/Zhongshan/ZS201505/2015（ZS201505）株外，2015 年 8 株气溶胶 H9N2 分离株和 2 株 H9N2 人类分离株的 8 个基因片段均位于同一进化枝中。在关键基因座变异方面，除 ZS201505 株外，H9N2 亚型 AIV 的血凝素（HA）8 个受体结合位点均无突变，神经氨酸酶（NA）蛋白的茎部有 3 个碱基缺失。ZS201503 和 ZS201602 的 PA 基因发生 L336M 突变。M1 基因的 N30D 和 T215A 突变以及 PB2 中的氨基酸残基 L89V、NS1 中的 P42S 和 M2 中的 S31N 在这 9 株 H9N2 分离株中得以保留，这可能增强了病毒的毒力。
中山市活禽市场空气中存在存活的 H9N2 AIV。气溶胶病毒与人类流行株具有密切的进化关系，提示 LPM 污染气溶胶中可能存在 AIV 向人类传播的风险。从 LPM 空气样本中分离出的 H9N2 亚型 AIV 的突变表明其致病性增强，能够感染人类。
