Environmental Levels of the Antiviral Oseltamivir Induce Development of Resistance Mutation H274Y in Influenza A/H1N1 Virus in Mallards
Environmental Levels of the Antiviral Oseltamivir Induce Development of Resistance Mutation H274Y in Influenza A/H1N1 Virus in Mallards
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DOI：
10.1371/journal.pone.0024742
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发表时间：
2011-09-12
期刊：
影响因子：
3.7
通讯作者：
Olsen, Bjorn
中科院分区：
文献类型：
--
作者：
Jarhult, Josef D.;Muradrasoli, Shaman;Olsen, Bjorn
奥司他韦（达菲（R））是最广泛使用的抗流感感染药物，作为大流行防备计划的一部分，在世界各地广泛储存。然而，耐药性是一个日益严重的问题，2008 - 2009年，世界大部分地区的季节性人流感A/H1N1病毒株在神经氨酸酶基因中携带H274 Y突变，导致对该药物产生耐药性。奥司他韦的活性代谢产物奥司他韦羧酸盐（OC）在污水处理厂和地表水中降解不良，并已在水生环境中检测到，在水生环境中，天然的流感水库，鸭子，可以暴露于该物质。为了评估在这些情况下是否会产生耐药性，我们用甲型H1N1流感病毒感染野鸭，并通过其唯一的水源将鸟类暴露于80 ng/L，1 μ g/L和80 μ g/L的OC。通过对粪便样本中的神经氨酸酶基因进行测序，我们发现H274Y在1 μ g/L OC时出现，并在80 μ g/L时迅速控制病毒种群。通过神经氨酸酶抑制试验测定，OC的IC50从野生型病毒的2 - 4 nM增加至H274Y突变体的400 - 700 nM。这与在携带H274 Y的人类临床分离株中观察到的对OC敏感性下降一致。在季节性疫情期间，环境中的有机碳水平被测量为58 - 293纳克/升，预计在大流行期间将达到微克/升的水平。因此，可以诱导野鸭中流行的流感病毒产生抗性。由于流感病毒可以跨越物种障碍，奥司他韦耐药性可能会传播到具有大流行潜力的人类适应型毒株，从而使奥司他韦失效，而奥司他韦是大流行防备规划的基石。我们建议在野鸟中进行监测，作为了解自然界中耐药性情况的一项措施，并随着时间的推移进行监测。降低环境中OC水平的策略包括改善污水处理，更重要的是，谨慎使用抗病毒药物。
Oseltamivir (Tamiflu (R)) is the most widely used drug against influenza infections and is extensively stockpiled worldwide as part of pandemic preparedness plans. However, resistance is a growing problem and in 2008-2009, seasonal human influenza A/H1N1 virus strains in most parts of the world carried the mutation H274Y in the neuraminidase gene which causes resistance to the drug. The active metabolite of oseltamivir, oseltamivir carboxylate (OC), is poorly degraded in sewage treatment plants and surface water and has been detected in aquatic environments where the natural influenza reservoir, dabbling ducks, can be exposed to the substance. To assess if resistance can develop under these circumstances, we infected mallards with influenza A/H1N1 virus and exposed the birds to 80 ng/L, 1 mu g/L and 80 mu g/L of OC through their sole water source. By sequencing the neuraminidase gene from fecal samples, we found that H274Y occurred at 1 mu g/L of OC and rapidly dominated the viral population at 80 mu g/L. IC50 for OC was increased from 2-4 nM in wild-type viruses to 400-700 nM in H274Y mutants as measured by a neuraminidase inhibition assay. This is consistent with the decrease in sensitivity to OC that has been noted among human clinical isolates carrying H274Y. Environmental OC levels have been measured to 58-293 ng/L during seasonal outbreaks and are expected to reach mu g/L-levels during pandemics. Thus, resistance could be induced in influenza viruses circulating among wild ducks. As influenza viruses can cross species barriers, oseltamivir resistance could spread to human-adapted strains with pandemic potential disabling oseltamivir, a cornerstone in pandemic preparedness planning. We propose surveillance in wild birds as a measure to understand the resistance situation in nature and to monitor it over time. Strategies to lower environmental levels of OC include improved sewage treatment and, more importantly, a prudent use of antivirals.