Dudin Gani Asa, Aziz Ibrahim M, Alzayed Rasha M, Ahmed Anwar, Hussain Tajamul, Somily Ali M, Alsaadi Muslim M, Almajhdi Fahad N
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
Biology Department, College of Science, Jouf University, Sakaka 41412, Saudi Arabia.
Vaccines (Basel). 2023 Mar 20;11(3):702. doi: 10.3390/vaccines11030702.
Presence of a large foreign workforce and the annual gathering of people for pilgrimage from around the globe have significantly contributed to the emergence and diversity of respiratory viruses in Saudi Arabia. Here, we report the sequence and phylogenetic analysis of the H3N2 subtype of influenza A virus (IAV) in clinical samples collected from Riyadh, Saudi Arabia. Based on RT-PCR, IAV was found in 88 (28.3%) of the 311 samples screened. Of the 88-IAV positive samples, 43 (48.8%) were H1N1 subtype while the remaining 45 (51.2%) were found to be of the H3N2 subtype. Complete sequencing of HA and NA genes of H3N2 revealed, twelve and nine amino acid (AA) substitutions respectively, and importantly, these variations are absent in the current vaccine strains. Based on the phylogenetic analysis, the majority of H3N2 strains were grouped in the same clades as the vaccine strains. Importantly, the N-glycosylation sites at AA 135(NSS) were found to be unique to 6 strains in the investigated HA1 protein and were absent in the current vaccine strains. These data may have significant clinical implications in designing novel and population-based vaccines for IAV and underscore the need for regular monitoring of efficacy of vaccines due to emerging variants.
大量外国劳动力的存在以及每年来自全球各地的朝圣者聚集，极大地促成了沙特阿拉伯呼吸道病毒的出现和多样性。在此，我们报告从沙特阿拉伯利雅得收集的临床样本中甲型流感病毒（IAV）H3N2亚型的序列和系统发育分析。基于逆转录聚合酶链反应（RT-PCR），在311份筛查样本中的88份（28.3%）中发现了IAV。在这88份IAV阳性样本中，43份（48.8%）为H1N1亚型，其余45份（51.2%）为H3N2亚型。对H3N2的血凝素（HA）和神经氨酸酶（NA）基因进行全序列分析发现，分别有12个和9个氨基酸（AA）替换，重要的是，这些变异在当前疫苗株中不存在。基于系统发育分析，大多数H3N2毒株与疫苗株归为同一进化枝。重要的是，在所研究的HA1蛋白中，6个毒株在氨基酸位置135（NSS）处的N-糖基化位点是独特的，且在当前疫苗株中不存在。这些数据可能对设计针对IAV的新型群体疫苗具有重要临床意义，并强调由于出现变异体而需要定期监测疫苗的效力。
