Low biological cost of carbapenemase-encoding plasmids following transfer from Klebsiella pneumoniae to Escherichia coli
Low biological cost of carbapenemase-encoding plasmids following transfer from Klebsiella pneumoniae to Escherichia coli
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DOI：
10.1093/jac/dkw350
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发表时间：
2017-01-01
影响因子：
5.2
通讯作者：
Samuelsen, Orjan
中科院分区：
文献类型：
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作者：
Di Luca, Maria Chiara;Sorum, Vidar;Samuelsen, Orjan
目的：本研究的目的是确定从肺炎克雷伯菌中分离的两个含bla（KPC-2）（pG 12-KPC-2）和bla（Vim-1）（pG 06-Vim-1）的碳青霉烯酶编码质粒在不同遗传背景的尿路致病性大肠杆菌临床分离株中的生物学成本、稳定性和序列。大肠杆菌临床分离株转化。新获得的质粒对宿主细胞的适应性效应在与相应的同基因菌株的头对头竞争中进行评估。通过将单一培养物繁殖类似312代来估计质粒稳定性。使用下一代测序技术测定质粒核苷酸序列。结果：两种质粒在4株E.大肠杆菌背景，并导致低至中度的主机健身从1.1%至3.6%的减少。pG 12-KPC-2在两种不同遗传背景下的适合度成本存在差异，而pG 06-Vim-1在三种不同遗传背景下的适合度成本没有差异。此外，在相同的遗传背景下，在pG 12-KPC-2和pG 06-Vim-1之间观察到差异。一般来说，质粒携带的生物学成本的大小是宿主和质粒依赖的。这两个质粒的序列与先前在克雷伯氏菌中循环的质粒显示出高度的骨架相似性。结论：在大肠杆菌中新获得并稳定维持的碳青霉烯酶编码质粒的适应性成本低至中等。大肠杆菌表明，建立和进一步传播到其他肠杆菌科物种的潜力。我们还表明，健身成本是质粒和主机特定的。
Objectives: The objective of this study was to determine the biological cost, stability and sequence of two carbapenemase-encoding plasmids containing bla(KPC-2) (pG12-KPC-2) and bla(VIM-1) (pG06-VIM-1) isolated from Klebsiella pneumoniae when newly acquired by uropathogenic Escherichia coli clinical isolates of different genetic backgrounds.Methods: The two plasmids were transferred into plasmid-free E. coli clinical isolates by transformation. The fitness effect of newly acquired plasmids on the host cell was assessed in head-to-head competitions with the corresponding isogenic strain. Plasmid stability was estimated by propagating monocultures for similar to 312 generations. Plasmid nucleotide sequences were determined using next-generation sequencing technology. Assembly, gap closure, annotation and comparative analyses were performed.Results: Both plasmids were stably maintained in three of four E. coli backgrounds and resulted in low to moderate reductions in host fitness ranging from 1.1% to 3.6%. A difference in fitness cost was observed for pG12-KPC-2 between two different genetic backgrounds, while no difference was detected for pG06-VIM-1 between three different genetic backgrounds. In addition, a difference was observed between pG12-KPC-2 and pG06-VIM-1 in the same genetic background. In general, the magnitude of biological cost of plasmid carriage was both host and plasmid dependent. The sequences of the two plasmids showed high backbone similarity to previously circulating plasmids in K. pneumoniae.Conclusions: The low to modest fitness cost of newly acquired and stably maintained carbapenemase-encoding plasmids in E. coli indicates a potential for establishment and further dissemination into other Enterobacteriaceae species. We also show that the fitness cost is both plasmid and host specific.