Detection of E119V and E119I Mutations in Influenza A (H3N2) Viruses Isolated from an Immunocompromised Patient: Challenges in Diagnosis of Oseltamivir Resistance
Detection of E119V and E119I Mutations in Influenza A (H3N2) Viruses Isolated from an Immunocompromised Patient: Challenges in Diagnosis of Oseltamivir Resistance
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DOI：
10.1128/aac.01608-09
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发表时间：
2010-05-01
影响因子：
4.9
通讯作者：
Gubareva, Larisa V.
中科院分区：
文献类型：
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作者：
Okomo-Adhiambo, Margaret;Demmler-Harrison, Gail J.;Gubareva, Larisa V.
神经氨酸酶抑制剂（NAI）奥司他韦的临床使用与亚型特异性神经氨酸酶（NA）突变引起的耐药性的出现有关。在化学发光神经氨酸酶抑制（NI）试验中，从接受奥司他韦治疗的免疫功能低下患者中分离出的甲型流感病毒/Texas/12/2007 （H3N2）病毒对奥司他韦的敏感性降低（与对照病毒相比，其50%的抑制浓度[IC50]增加了60倍）。当在细胞培养中进一步繁殖时，该分离物在化学发光和荧光NI检测中对奥司他韦的敏感性均降低（IC50分别增加50倍和350倍）。对该分离物进行测序分析，发现NA第119位氨基酸的核苷酸编码组合[E119(V/I)]。分离物的空斑纯化产生E119V和E119I变体，两者都表现出对奥司他韦的敏感性降低。E119I变异也显示对扎那米韦和研究中的nai - peramivir和A-315675的敏感性降低。此前曾有奥司他韦治疗患者中出现E119V变异的报道；然而，这里检测到的E119I突变是一种新的突变，它降低了对几种nai的易感性。在未繁殖的原始临床标本中，使用常规测序或焦磷酸测序均未检测到这两种突变，这表明这些变异的比例非常低(
The clinical use of the neuraminidase inhibitor (NAI) oseltamivir is associated with the emergence of drug resistance resulting from subtype-specific neuraminidase (NA) mutations. The influenza A/Texas/12/2007 (H3N2) virus isolated from an oseltamivir-treated immunocompromised patient exhibited reduced susceptibility to oseltamivir in the chemiluminescent neuraminidase inhibition (NI) assay (similar to 60-fold increase in its 50% inhibitory concentration [IC50] compared to that for a control virus). When further propagated in cell culture, the isolate maintained reduced susceptibility to oseltamivir in both chemiluminescent and fluorescent NI assays (similar to 50-and 350-fold increases in IC50, respectively). Sequencing analysis of the isolate revealed a mix of nucleotides coding for amino acids at position 119 of the NA [E119(V/I)]. Plaque purification of the isolate yielded E119V and E119I variants, both exhibiting reduced susceptibility to oseltamivir. The E119I variant also showed decreased susceptibility to zanamivir and the investigational NAIs peramivir and A-315675. The emergence of E119V variants in oseltamivir-treated patients has been previously reported; however, the E119I mutation detected here is a novel one which reduces susceptibility to several NAIs. Both mutations were not detected in unpropagated original clinical specimens using either conventional sequencing or pyrosequencing, suggesting that these variants were present in very low proportions (