The major Gram-negative gated efflux channel TolC has been extensively characterized in Escherichia coli but there is minimal information about Klebsiella pneumoniae TolC. Using an arabinose-inducible plasmid-based expression system, we show that the K. pneumoniae TolC complements the efflux defect in an E. coli K-12 ΔtolC strain, restoring wild-type levels of resistance towards most antibiotics suggesting that it can interact with the E. coli AcrB efflux pump. We characterize the efflux properties of K. pneumoniae TolC using an orthogonal whole cell-based assay and quantify the extrusion of environment-sensitive fluorescent probes and contrast the findings with the E. coli ortholog.

中文翻译：

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肺炎克雷伯菌TolC孔蛋白在抗生素外排中的作用。

革兰氏阴性门控主要外排通道TolC在大肠杆菌中已得到广泛鉴定，但有关肺炎克雷伯菌TolC的信息很少。使用基于阿拉伯糖诱导的质粒的表达系统，我们显示肺炎克雷伯菌TolC补充了大肠杆菌K-12ΔtolC菌株的外排缺陷，恢复了对大多数抗生素的抗性水平，表明它可以与大肠杆菌AcrB外排泵。我们使用正交的基于全细胞的测定来表征肺炎克雷伯菌TolC的外排特性，并量化对环境敏感的荧光探针的挤出量，并将结果与​​大肠杆菌直系同源物进行对比。