Plasmids persist in a microbial community by providing fitness benefit to multiple phylotypes
Plasmids persist in a microbial community by providing fitness benefit to multiple phylotypes
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DOI：
10.1038/s41396-020-0596-4
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发表时间：
2020-02-04
期刊：
影响因子：
11
通讯作者：
Smets, Barth F.
中科院分区：
文献类型：
--
作者：
Li, Liguan;Dechesne, Arnaud;Smets, Barth F.
抗生素耐药基因（ARG）在微生物群落中广泛而快速的水平传播促进了当前抗生素耐药性的流行。事实上，ARG通常位于质粒上，可以有效地将基因穿梭于不同的类群。虽然质粒的存在条件已经在一些模式细菌种群中得到了广泛的研究，但它们在复杂细菌群落中的命运却知之甚少。在这里，我们耦合质粒转移试验与一系列的生长实验，调查持久性的广泛的主机范围IncP-1质粒pKJK 5在微生物群落来自污水处理厂。培养条件结合不同的营养和氧气水平，是非选择性的，不利于液相接合转移。初始转移后，质粒在10天的连续生长实验（相当于60代）中几乎在所有条件下都能持续存在，瞬时接合转移发生率高达30%。通过将细胞计数和分选与扩增子测序相结合，我们绘制了跨微生物群落类群的质粒适应性效应。在气单胞菌属、肠杆菌科和假单胞菌属的多种细菌类型中观察到了意想不到的质粒适应性益处，这导致了社区水平的质粒持久性。我们证明，第一次，可以在高通量估计，无需事先隔离的质粒健身社区成员的影响。通过在携带质粒时获得适应性益处，复杂微生物群落中的成员可能具有迄今未被认识到的维持质粒以供长期社区范围访问的潜力。
The current epidemic of antibiotic resistance has been facilitated by the wide and rapid horizontal dissemination of antibiotic resistance genes (ARGs) in microbial communities. Indeed, ARGs are often located on plasmids, which can efficiently shuttle genes across diverse taxa. While the existence conditions of plasmids have been extensively studied in a few model bacterial populations, their fate in complex bacterial communities is poorly understood. Here, we coupled plasmid transfer assays with serial growth experiments to investigate the persistence of the broad-host-range IncP-1 plasmid pKJK5 in microbial communities derived from a sewage treatment plant. The cultivation conditions combined different nutrient and oxygen levels, and were non-selective and non-conducive for liquid-phase conjugal transfer. Following initial transfer, the plasmid persisted in almost all conditions during a 10-day serial growth experiment (equivalent to 60 generations), with a transient transconjugant incidence up to 30%. By combining cell enumeration and sorting with amplicon sequencing, we mapped plasmid fitness effects across taxa of the microbial community. Unexpected plasmid fitness benefits were observed in multiple phylotypes of Aeromonas, Enterobacteriaceae, and Pseudomonas, which resulted in community-level plasmid persistence. We demonstrate, for the first time, that plasmid fitness effects across community members can be estimated in high-throughput without prior isolation. By gaining a fitness benefit when carrying plasmids, members within complex microbial communities might have a hitherto unrecognised potential to maintain plasmids for long-term community-wide access.