Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution
Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution
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DOI：
10.1098/rstb.2016.0040
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发表时间：
2017-01-19
影响因子：
6.3
通讯作者：
Hiltunen, Teppo
中科院分区：
文献类型：
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作者：
Cairns, Johannes;Becks, Lutz;Hiltunen, Teppo
在自然环境中，由于人类活动导致抗生素广泛泄漏，抗生素的次最低抑菌浓度（sub-MIC）经常出现。尽管浓度非常低，但最近已显示这些亚MIC通过选择抗生素抗性和增加适应性进化的速率来改变细菌种群。然而，缺乏关于这些影响如何影响关键生态相互作用的研究，例如细菌-噬菌体相互作用。以前，由于与耐药突变相关的适应性成本，已经假设细菌的共同选择和超过MIC的抗生素浓度会降低耐药进化的速率。相比之下，在这里，我们表明抗生素链霉素（Sm）的亚MIC增加了噬菌体耐药性进化的速率，以及导致噬菌体的灭绝。值得注意的是，Sm和噬菌体组合也增强了Sm抗性的演变相比，单独的Sm。这些观察结果表明，抗生素的亚MIC可能会影响微生物群落中的关键生态相互作用，其进化结果可能与高浓度相关的结果完全不同。我们的研究结果也有助于理解生态和进化因素对抗生素耐药性问题的管理至关重要。本文是主题问题“人类对进化的影响，以及生态和社会后果”的一部分。
Sub-minimum inhibiting concentrations (sub-MICs) of antibiotics frequently occur in natural environments owing to wide-spread antibiotic leakage by human action. Even though the concentrations are very low, these sub-MICs have recently been shown to alter bacterial populations by selecting for antibiotic resistance and increasing the rate of adaptive evolution. However, studies are lacking on how these effects reverberate into key ecological interactions, such as bacteria-phage interactions. Previously, co-selection of bacteria by phages and antibiotic concentrations exceeding MICs has been hypothesized to decrease the rate of resistance evolution because of fitness costs associated with resistance mutations. By contrast, here we show that sub-MICs of the antibiotic streptomycin (Sm) increased the rate of phage resistance evolution, as well as causing extinction of the phage. Notably, Sm and the phage in combination also enhanced the evolution of Sm resistance compared with Sm alone. These observations demonstrate the potential of sub-MICs of antibiotics to impact key ecological interactions in microbial communities with evolutionary outcomes that can radically differ from those associated with high concentrations. Our findings also contribute to the understanding of ecological and evolutionary factors essential for the management of the antibiotic resistance problem.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.