State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Department of laboratory medicine, 5th medical center of PLA general hospital, Beijing, 100071, China.
J Antibiot (Tokyo). 2021 Aug;74(8):528-537. doi: 10.1038/s41429-021-00427-0. Epub 2021 May 28.
Trans-translation is a unique bacterial ribosome rescue system that plays important roles in the tolerance to environmental stresses. It is composed of an ssrA-encoded tmRNA and a protein SmpB. In this study, we examined the role of trans-translation in antibiotic tolerance in Klebsiella pneumoniae and explored whether the inhibition of this mechanism could enhance the bactericidal activities of antibiotics. We found that deletion of the ssrA gene reduced the survival of K. pneumoniae after treatment with kanamycin, tobramycin, azithromycin, and ciprofloxacin, indicating an important role of the trans-translation in bacterial antibiotic tolerance. By using a modified ssrA gene with a 6×His tag we demonstrated that tobramycin suppressed the azithromycin and ciprofloxacin-elicited activation of trans-translation. The results were further confirmed with a trans-translation reporter system that is composed of a normal mCherry gene and a gfp gene without the stop codon. Compared to each individual antibiotic, combination of tobramycin with azithromycin or ciprofloxacin synergistically enhanced the killing activities against planktonic K. pneumoniae cells and improved bacterial clearance in a murine cutaneous abscess infection model. In addition, the combination of tobramycin and ciprofloxacin increased the bactericidal activities against biofilm-associated cells. Overall, our results suggest that the combination of tobramycin with azithromycin or ciprofloxacin is a promising strategy in combating K. pneumoniae infections.
反翻译是一种独特的细菌核糖体救援系统，在耐受环境压力方面发挥着重要作用。它由一个 ssrA 编码的 tmRNA 和一个蛋白质 SmpB 组成。在这项研究中，我们研究了反翻译在肺炎克雷伯氏菌抗生素耐药性中的作用，并探讨了抑制这种机制是否能增强抗生素的杀菌活性。我们发现，ssrA 基因缺失会降低肺炎克雷伯氏菌在用卡那霉素、妥布霉素、阿奇霉素和环丙沙星治疗后的存活率，表明反翻译在细菌抗生素耐药性中起着重要作用。通过使用带有 6×His 标签的修饰后的 ssrA 基因，我们证明妥布霉素抑制了阿奇霉素和环丙沙星诱导的反翻译激活。通过由正常 mCherry 基因和没有终止密码子的 gfp 基因组成的反翻译报告系统进一步证实了这一结果。与每种单独的抗生素相比，妥布霉素与阿奇霉素或环丙沙星联合使用可协同增强对浮游肺炎克雷伯氏菌细胞的杀伤活性，并改善小鼠皮肤脓肿感染模型中的细菌清除率。此外，妥布霉素和环丙沙星的联合使用增加了对生物膜相关细胞的杀菌活性。总的来说，我们的研究结果表明，妥布霉素与阿奇霉素或环丙沙星联合使用是治疗肺炎克雷伯氏菌感染的一种有前途的策略。
