Niu Dan-Dan, Fang Shi-Song, Chen Zhi-Gao, Lv Qiu-Ying, Liu Ting-Ting, Chen Ni-Xuan, Li Ying-Ying, Sun Ying, Li Chao, Huang Shun-Wu, Cheng Yan-Peng, Wang Hong-Lin, Wen Ying, Chen Yi-Xiong, Zhang Xin-Dong, Lu Jian-Hua, Shi Xiao-Lu, Zhang Zhen, Zou Xuan, Feng Tie-Jian
Shenzhen Center for Disease Control and Prevention, Shenzhen, Guangdong Province, China.
Baoan Center for Disease Control and Prevention, Shenzhen, Guangdong Province, China.
Front Microbiol. 2025 Oct 13;16:1692162. doi: 10.3389/fmicb.2025.1692162. eCollection 2025.
Human adenovirus type 21 (HAdV-21) is recognized as an important pathogen responsible for acute respiratory infections (ARIs). However, it has been rarely reported and remains poorly characterized to date in China. Outpatient or inpatient children under 14 years old with suspected ARIs were enrolled from two hospitals in Shenzhen from September 2023 to April 2024. Respiratory samples were collected and tested for 22 common respiratory pathogens. A comparative analysis was conducted on the positive proportions of pathogens among different groups. Phylogenetic analysis and amino acid mutation analysis were conducted for HAdV-21 strains. A total of 498 pediatric patients with ARIs were enrolled. There were 366 (73.5%) patients infected with at least one pathogen, and 133 (26.7%) patients co-infected with other pathogens. The most frequently detected pathogens were () (30.7%, 153/498), HAdV (16.7%, 83/498), and influenza virus (IFV) (16.5%, 82/498). The positive HAdV-21 strain was sequenced and classified as subtype 21a with genome closely related to other strains found in China, and compared with HAdV-21 strains GZ09107, GZ06109 and BB/201903 in China, Shenzhen-2024-5-ILI-1109 contained only one amino acid insertion mutation in the penton base (GTT, Valine). Phylogenetic analysis for whole genome and major antigen proteins showed that global HAdV-21 strains could be classified into two branches, branch 1 including genotype 21p, branch 2 including subtype 21a and 21b. There were three highly variable regions (HVR3, HVR4, and HVR7) in the hexon protein that varied between two branches. This study initially reported a case of HAdV-21a infection in children in Shenzhen, and the genome showed one amino acid insertion mutation in the penton base compared with reported HAdV-21 strains in China. Our findings may contribute to a better understanding of the molecular epidemiological characteristics of HAdV-21 strains, as well as aid in the development of vaccines.
人21型腺病毒（HAdV - 21）被认为是引起急性呼吸道感染（ARI）的重要病原体。然而，在中国，其报道较少，至今特征仍不明确。2023年9月至2024年4月，从深圳两家医院招募了14岁以下疑似ARI的门诊或住院儿童。采集呼吸道样本并检测22种常见呼吸道病原体。对不同组病原体的阳性比例进行了比较分析。对HAdV - 21毒株进行了系统发育分析和氨基酸突变分析。共纳入498例ARI儿科患者。366例（73.5%）患者感染了至少一种病原体，133例（26.7%）患者合并感染了其他病原体。最常检测到的病原体是（）（30.7%，153/498）、HAdV（16.7%，83/498）和流感病毒（IFV）（16.5%，82/498）。对阳性HAdV - 21毒株进行测序，分类为21a亚型，其基因组与在中国发现的其他毒株密切相关，与中国的HAdV - 21毒株GZ09107、GZ06109和BB/201903相比，深圳 - 2024 - 5 - ILI - 1109在五邻体基座中仅含有一个氨基酸插入突变（GTT，缬氨酸）。对全基因组和主要抗原蛋白的系统发育分析表明，全球HAdV - 21毒株可分为两个分支，分支1包括21p基因型，分支2包括21a和21b亚型。六邻体蛋白中有三个高变区（HVR3、HVR4和HVR7）在两个分支之间存在差异。本研究首次报道了深圳儿童感染HAdV - 21a的病例，与中国报道的HAdV - 21毒株相比，该基因组在五邻体基座中显示一个氨基酸插入突变。我们的研究结果可能有助于更好地了解HAdV - 21毒株的分子流行病学特征，并有助于疫苗的研发。
