Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Laboratory Medicine, National University Hospital, National University Health System, Singapore, Singapore.
Clinical Microbiology, Leicester Royal Infirmary, Leicester, United Kingdom.
PLoS One. 2015 Jan 30;10(1):e0117822. doi: 10.1371/journal.pone.0117822. eCollection 2015.
Adamantanes and neuraminidase inhibitors (NAIs) are two classes of antiviral drugs available for the chemoprophylaxis and treatment of influenza infections. To determine the frequency of drug resistance in influenza A/H3N2 viruses in Singapore, large-scale sequencing of neuraminidase (NA) and matrix protein (MP) genes was performed directly without initial culture amplification. 241 laboratory-confirmed influenza A/H3N2 clinical samples, collected between May 2009 and November 2013 were included. In total, 229 NA (95%) and 241 MP (100%) complete sequences were obtained. Drug resistance mutations in the NA and MP genes were interpreted according to published studies. For the NAIs, a visual inspection of the aligned NA sequences revealed no known drug resistant genotypes (DRGs). For the adamantanes, the well-recognised S31N DRG was identified in all 241 MP genes. In addition, there was an increasing number of viruses carrying the combination of D93G+Y155F+D251V (since May 2013) or D93G (since March 2011) mutations in the NA gene. However, in-vitro NAI testing indicated that neither D93G+Y155F+D251V nor D93G alone conferred any changes in NAI susceptibility. Lastly, an I222T mutation in the NA gene that has previously been reported to cause oseltamivir-resistance in influenza A/H1N1/2009, B, and A/H5N1, was detected from a treatment-naïve patient. Further in-vitro NAI testing is required to confirm the effect of this mutation in A/H3N2 virus.
金刚烷胺和神经氨酸酶抑制剂（NAIs）是两类可用于流感感染的化学预防和治疗的抗病毒药物。为了确定新加坡甲型 H3N2 流感病毒的耐药频率，直接进行了大规模的神经氨酸酶（NA）和基质蛋白（MP）基因测序，而无需初始培养扩增。共纳入了 2009 年 5 月至 2013 年 11 月期间采集的 241 份实验室确诊的甲型 H3N2 临床样本。总共获得了 229 个 NA（95%）和 241 个 MP（100%）完整序列。根据已发表的研究对 NA 和 MP 基因中的耐药突变进行了解释。对于 NAI，对对齐的 NA 序列进行目视检查并未发现已知的耐药基因型（DRGs）。对于金刚烷胺，在所有 241 个 MP 基因中都发现了公认的 S31N DRG。此外，自 2013 年 5 月以来，越来越多的病毒在 NA 基因中携带 D93G+Y155F+D251V 或 D93G（自 2011 年 3 月以来）组合突变。然而，体外 NAI 测试表明，D93G+Y155F+D251V 或 D93G 单独突变均未导致 NAI 敏感性发生变化。最后，从一位未接受过治疗的患者中检测到了 NA 基因中的 I222T 突变，该突变先前已被报道可导致甲型 H1N1/2009、B 和 A/H5N1 流感病毒对奥司他韦产生耐药性。需要进一步进行体外 NAI 测试以确认该突变对 A/H3N2 病毒的影响。
