Neuraminidase sequence analysis and susceptibilities of influenza virus clinical isolates to zanamivir and oseltamivir
Neuraminidase sequence analysis and susceptibilities of influenza virus clinical isolates to zanamivir and oseltamivir
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DOI：
10.1128/aac.47.7.2264-2272.2003
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发表时间：
2003-07-01
影响因子：
4.9
通讯作者：
Zambon, A
中科院分区：
文献类型：
--
作者：
McKimm-Breschkin, J;Trivedi, T;Zambon, A
流感病毒神经氨酸酶（NA）抑制剂扎那米韦和奥司他韦在1999年至2002年期间被引入世界各地的临床实践。为了监测耐药性的潜在发展，建立了神经氨酸酶抑制剂敏感性网络，以协调通过世界卫生组织流感监测网络从世界不同地区收集的临床分离株的检测（M. Zambon和F. G. Hayden, Antivir）。Res. 49:147-156, 2001)。本研究建立了在引入NA抑制剂之前和之后不久的基线敏感性。在1996年至1999年期间，对回收的1 000多个临床流感分离株进行了检测。以已知NA抑制剂抗性病毒为对照，用化学发光或荧光底物进行酶抑制试验来确定其敏感性。50%的抑制浓度（IC(50)s）取决于检测方法、测试药物和流感病毒亚型。两种检测结果显示，对H1N1 （N1）、H3N2 （N2）和B亚型NAs，扎那米韦的平均IC50S分别为0.76、1.82和2.28 nM；对N1、N2和B亚型NAs，奥司他韦的IC50S分别为1.2、0.5和8.8 nM。已知NA突变为E119V、R292K、H274Y和R152K的扎那米韦和奥司他韦耐药病毒的药物敏感性远远超出了所有天然分离株的IC(50)s的95%置信限。对IC(50)s高于95%置信限的病毒和IC(50)s在正常范围内的几个对照分离物的序列分析显示，一些先前保守的残基发生了变化，包括D151、A203、T225和E375 （N2编号）。已知的耐药突变是流感病毒亚型和药物特异性突变，但没有证据表明在任何分离株中对这两种药物自然产生耐药性。
The influenza virus neuraminidase (NA) inhibitors zanamivir and oseltamivir were introduced into clinical practice in various parts of the world between 1999 and 2002. In order to monitor the potential development of resistance, the Neuraminidase Inhibitor Susceptibility Network was established to coordinate testing of clinical isolates collected through the World Health Organization influenza surveillance network from different regions of the world (M. Zambon and F. G. Hayden, Antivir. Res. 49:147-156, 2001). The present study establishes the baseline susceptibilities prior to and shortly after the introduction of the NA inhibitors. Over 1,000 clinical influenza isolates recovered from 1996 to 1999 were tested. Susceptibilities were determined by enzyme inhibition assays with chemiluminescent or fluorescent substrates with known NA inhibitor-resistant viruses as controls. The 50% inhibitory concentrations (IC(50)s) depended upon the assay method, the drug tested, and the influenza virus subtype. By both assays, the mean zanamivir IC50S were 0.76, 1.82, and 2.28 nM for the subtype H1N1 (N1), H3N2 (N2), and B NAs, respectively, and the oseltamivir IC(50)s were 1.2, 0.5, and 8.8 nM for the N1, N2, and B NAs, respectively. The drug susceptibilities of known zanamivir- and oseltamivir-resistant viruses with the NA mutations E119V, R292K, H274Y, and R152K fell well outside the 95% confidence limits of the IC(50)s for all natural isolates. Sequence analysis of the NAs of viruses for which the IC(50)s were above the 95% confidence limits and several control isolates for which the IC(50)s were in the normal range revealed variations in some previously conserved residues, including D151, A203, T225, and E375 (N2 numbering). Known resistance mutations are both influenza virus subtype and drug specific, but there was no evidence of naturally occurring resistance to either drug in any of the isolates.