Black Queen Evolution and Trophic Interactions Determine Plasmid Survival after the Disruption of the Conjugation Network.
Black Queen Evolution and Trophic Interactions Determine Plasmid Survival after the Disruption of the Conjugation Network.
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DOI：
10.1128/msystems.00104-18
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发表时间：
2018-09
期刊：
影响因子：
6.4
通讯作者：
Jalasvuori M
中科院分区：
文献类型：
--
作者：
Cairns J;Koskinen K;Penttinen R;Patinen T;Hartikainen A;Jokela R;Ruusulehto L;Viitamäki S;Mattila S;Hiltunen T;Jalasvuori M
细菌抗生素耐药性通常是移动基因元素的一部分，从一个细菌转移到另一个细菌。通过干扰水平运动和维护这些元素，可以消除人群的阻力。在这里，我们展示了所谓的质粒依赖噬菌体导致最初耐药的细菌群体变得对抗生素敏感。然而，当系统中还含有以细菌为食的捕食者时，这种影响就被有效地抵消了。此外，当环境中含有抗生素时，耐药的生存依赖于耐药机制。当细菌可以帮助它们的同代人降解抗生素时，只有一小部分细菌保持耐药性。另一方面，当细菌不能帮助其他细菌时，所有细菌都保持耐药性。抗生素的浓度所起的作用不如所使用的抗生素显著。该报告表明，细菌群落中抗生素耐药性的存活代表了一个复杂的过程，其中现实系统中存在的许多因素决定了耐药性是否实际丧失。在许多细菌病原体中，共轭质粒等可移动的遗传因子是造成抗生素抗性表型的原因。结合的能力、抗生素的存在和生态相互作用都对细菌种群中质粒的持久性起着显著的作用。在这里，我们着手研究当偶联网络被依赖质粒的噬菌体干扰时，这些因素的贡献。噬菌体单独有效地导致种群失去质粒，从而使它们对抗生素敏感。在决定质粒流行率方面，允许黑皇后进化的抗生素耐药机制的漏洞（即“竞次”）是比抗生素浓度（致命与亚致命）更重要的因素。有趣的是，原生动物捕食也能防止质粒丢失。这些结果表明，试图通过破坏偶联网络使细菌群落重致敏的结果高度依赖于生态因素和耐药机制。细菌抗生素耐药性通常是可移动遗传元素的一部分，从一个细菌转移到另一个细菌。通过干扰水平运动和维护这些元素，可以消除人群的阻力。在这里，我们展示了所谓的质粒依赖噬菌体导致最初耐药的细菌群体变得对抗生素敏感。然而，当系统中还含有以细菌为食的捕食者时，这种影响就被有效地抵消了。此外，当环境中含有抗生素时，耐药的生存依赖于耐药机制。当细菌可以帮助它们的同代人降解抗生素时，只有一小部分细菌保持耐药性。另一方面，当细菌不能帮助其他细菌时，所有细菌都保持耐药性。抗生素的浓度所起的作用不如所使用的抗生素显著。该报告表明，细菌群落中抗生素耐药性的存活代表了一个复杂的过程，其中现实系统中存在的许多因素决定了耐药性是否实际丧失。
Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost. Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a “race to the bottom”) was a more significant factor than the antibiotic concentration (lethal vs sublethal) in determining plasmid prevalence. Interestingly, plasmid loss was also prevented by protozoan predation. These results show that outcomes of attempts to resensitize bacterial communities by disrupting the conjugation network are highly dependent on ecological factors and resistance mechanisms. IMPORTANCE Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost.