Wang Xin, Ma Wenru, Shan Jiangfan, Chen Kexu, Xu Weihao, Lu Zixuan, Ju Zhuofei, Dong Zhouyan, Li Boqing, Zhang Yumei
Department of Pathogenic Biology, Binzhou Medical University, Yantai, China.
The Second School of Clinical Medicine, Binzhou Medical University, Yantai, China.
Int J Antimicrob Agents. 2023 Oct;62(4):106925. doi: 10.1016/j.ijantimicag.2023.106925. Epub 2023 Jul 12.
Klebsiella pneumoniae is one of the most common opportunistic pathogens causing hospital- and community-acquired infections. Antibiotic resistance in K. pneumoniae has emerged as a major clinical and public health threat. Persisters are specific antibiotic-tolerant bacterial cells. Studies on the mechanism underlying their formation mechanism and growth status are scarce. Therefore, it is urgent to explore the key genes and signalling pathways involved in the formation and recovery process of K. pneumoniae persisters to enhance the understanding and develop relevant treatment strategies. In this study, we treated K. pneumoniae with a lethal concentration of levofloxacin. It resulted in a distinct plateau of surviving levofloxacin-tolerant persisters. Subsequently, we obtained bacterial samples at five different time points during the formation and recovery of K. pneumoniae persisters to perform transcriptome analysis. ptsH gene was observed to be upregulated during the formation of persisters, and down-regulated during the recovery of the persisters. Further, we used CRISPR-Cas9 to construct ΔptsH, the ptsH-knockout K. pneumoniae strain, and to investigate the effect of ptsH on the persister formation. We observed that ptsH can promote the formation of persisters, reduce accumulation of reactive oxygen species, and enhance antioxidant capacity by reducing cyclic adenosine monophosphate (cAMP) levels. To the best of our knowledge, this is the first study to report that ptsH plays a vital role in forming K. pneumoniae persisters. This study provided important insights to further explore the mechanism underlying the formation of K. pneumoniae persisters and provided a potential target for treating infection with K. pneumoniae persisters.
肺炎克雷伯菌是引起医院获得性感染和社区获得性感染的最常见机会性病原体之一。肺炎克雷伯菌的抗生素耐药性已成为主要的临床和公共卫生威胁。持留菌是一类特殊的耐受抗生素的细菌细胞。关于其形成机制和生长状态的研究较少。因此，迫切需要探索参与肺炎克雷伯菌持留菌形成和复苏过程的关键基因和信号通路，以加深理解并制定相关治疗策略。在本研究中，我们用致死浓度的左氧氟沙星处理肺炎克雷伯菌。这导致了耐左氧氟沙星持留菌存活数量出现明显的平稳期。随后，我们在肺炎克雷伯菌持留菌形成和复苏的五个不同时间点获取细菌样本进行转录组分析。观察到ptsH基因在持留菌形成过程中上调，而在持留菌复苏过程中下调。此外，我们使用CRISPR-Cas9构建了ΔptsH，即ptsH基因敲除的肺炎克雷伯菌菌株，并研究ptsH对持留菌形成的影响。我们观察到ptsH可促进持留菌的形成，减少活性氧的积累，并通过降低环磷酸腺苷（cAMP）水平增强抗氧化能力。据我们所知，这是首次报道ptsH在肺炎克雷伯菌持留菌形成中起关键作用的研究。本研究为进一步探索肺炎克雷伯菌持留菌形成机制提供了重要见解，并为治疗肺炎克雷伯菌持留菌感染提供了潜在靶点。
