Abed Yacine, Schibler Manuel, Checkmahomed Liva, Carbonneau Julie, Venable Marie-Christine, Fage Clément, Giannotti Federica, Goncalves Ana Rita, Kaiser Laurent, Boivin Guy
Research Center in Infectious Diseases of the CHUQ-CHUL and Laval University, Québec City, QC, Canada.
Laboratory of Virology, Geneva University Hospitals, Geneva, Switzerland.
Antivir Ther. 2019;24(8):581-587. doi: 10.3851/IMP3344.
Neuraminidase (NA) inhibitors (NAIs), including oseltamivir and zanamivir, play an important therapeutic role against influenza infections in immunocompromised patients. In such settings, however, NAI therapy may lead to the emergence of resistance involving mutations within the influenza surface genes. The aim of this study was to investigate the evolution of NA and haemagglutinin (HA) genes of influenza A(H1N1)pdm09 virus in an immunocompromised patient receiving oseltamivir then zanamivir therapies.
Nasopharyngeal swab (NPS) samples were collected between 27 January 2018 and 11 April 2018 from a haematopoietic stem cell transplant recipient. These include 10 samples collected either pre-therapy, during oseltamivir and zanamivir treatment as well as after therapy. The A(H1N1)pdm09 HA/NA genes were sequenced. The H275Y NA substitution was quantified by droplet digital RT-PCR assay. A(H1N1)pdm09 recombinant viruses containing HA mutations were tested by HA elution experiments to investigate in vitro binding properties.
Oseltamivir rapidly induced the H275Y NA mutation which constituted 98.33% of the viral population after 15 days of oseltamivir treatment. The related HA gene contained S135A and P183S substitutions within the receptor-binding site. After a switch to zanamivir, 275H/Y and 119E/G/D mixed populations were detected. In the last samples, the double H275Y-E119G NA variant dominated with S135A and P183S HA substitutions.
This report confirms that oseltamivir can rapidly induce the emergence of the H275Y substitution in A(H1N1)pdm09 viruses and subsequent switch to zanamivir can lead to additional substitutions at codon E119 resulting in multi-drug resistance. Such data additionally suggest a potential compensatory role for HA substitutions near the receptor binding site.
神经氨酸酶（NA）抑制剂，包括奥司他韦和扎那米韦，在免疫功能低下患者的流感感染治疗中发挥着重要作用。然而，在这种情况下，NAI治疗可能导致流感表面基因内发生涉及突变的耐药性出现。本研究的目的是调查在一名接受奥司他韦然后扎那米韦治疗的免疫功能低下患者中，甲型H1N1pdm09流感病毒的NA和血凝素（HA）基因的演变情况。
于2018年1月27日至2018年4月11日期间，从一名造血干细胞移植受者处采集鼻咽拭子（NPS）样本。这些样本包括在治疗前、奥司他韦和扎那米韦治疗期间以及治疗后采集的10个样本。对甲型H1N1pdm09 HA/NA基因进行测序。通过液滴数字RT-PCR测定法对H275Y NA替代进行定量。通过HA洗脱实验对含有HA突变的甲型H1N1pdm09重组病毒进行测试，以研究其体外结合特性。
奥司他韦迅速诱导了H275Y NA突变，在奥司他韦治疗15天后，该突变占病毒群体的98.33%。相关的HA基因在受体结合位点内含有S135A和P183S替代。在改用扎那米韦后，检测到275H/Y和119E/G/D混合群体。在最后一批样本中，双重H275Y-E119G NA变体占主导地位，同时伴有S135A和P183S HA替代。
本报告证实，奥司他韦可迅速诱导甲型H1N1pdm09病毒中出现H275Y替代，随后改用扎那米韦可导致E119密码子处出现额外替代，从而产生多药耐药性。这些数据还表明受体结合位点附近的HA替代可能具有潜在的补偿作用。
