Host and invader impact of transfer of the clc genomic island into Pseudomonas aeruginosa PAO1
Host and invader impact of transfer of the clc genomic island into Pseudomonas aeruginosa PAO1
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DOI：
10.1073/pnas.0801269105
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发表时间：
2008-05-13
影响因子：
11.1
通讯作者：
van der Meer, Jan Roelof
中科院分区：
文献类型：
--
作者：
Gaillard, Muriel;Pernet, Nataskha;van der Meer, Jan Roelof
基因组岛是细菌染色体的大片潜在可移动区域，是细菌进化的主要贡献者。在这里，我们研究了铜绿假单胞菌PAO1和携带一个整合拷贝的CLC元件的衍生物，一个103 kb的基因组岛[和整合和结合元件(ICE)]起源于假单胞菌的适应成本和表型差异。菌株B13和在临床和环境分离的铜绿假单胞菌中发现的基因组岛的近亲。通过结合全基因组转录组图谱、表型阵列、竞争实验和生物膜形成研究，只有少数差异变得明显，例如在含有CLC元件的PAO1中，生物膜生长减少，参与乙酸代谢的基因受到四倍静止时相抑制。相反，携带CLC元素的PAO1获得了在3-氯苯甲酸酯和2-氨基苯酚作为唯一碳和能量底物上生长的能力。在携带CLC元件的PAO1和PAO1之间的竞争实验中没有检测到适应度损失>；1%。来自CLC元件的基因在PAO1中并不是沉默的，并且观察到了切除，尽管从PAO1到其他受体细菌的CLC转移减少了两个数量级。我们的结果表明，新获得的移动DNA不一定会在宿主上产生重要的适应成本。缺乏对宿主的直接损害可能是导致细菌基因组中像CLC这样的基因组岛广泛分布的原因之一。
Genomic islands, large potentially mobile regions of bacterial chromosomes, are a major contributor to bacteria evolution. Here, we investigated the fitness cost and phenotypic differences between the bacterium Pseudomonas aeruginosa PAO1 and a derivative carrying one integrated copy of the clc element, a 103-kb genomic island [and integrative and conjugative element (ICE)] originating in Pseudomonas sp. strain B13 and a close relative of genomic islands found in clinical and environmental isolates of A aeruginosa. By using a combination of whole genome transcriptome profiling, phenotypic arrays, competition experiments, and biofilm formation studies, only few differences became apparent, such as reduced biofilm growth and fourfold stationary phase repression of genes involved in acetoin metabolism in PAO1 containing the clc element. In contrast, PAO1 carrying the clc element acquired the capacity to grow on 3-chlorobenzoate and 2-aminophenol as sole carbon and energy substrates. No fitness loss >1% was detectable in competition experiments between PAO1 and PAO1 carrying the clc element. The genes from the clc element were not silent in PAO1, and excision was observed, although transfer of clc from PAO1 to other recipient bacteria was reduced by two orders of magnitude. Our results indicate that newly acquired mobile DNA not necessarily invoke an important fitness cost on their host. Absence of immediate detriment to the host may have contributed to the wide distribution of genomic islands like clc in bacterial genomes.