氨基糖苷类抗生素靶向核糖体并且对多种细菌有效。这里,我们证明,与大肠杆菌能量代谢相关的敲除菌株在指数生长中期对氨基糖苷类药物的耐受性增加。与预期相反,这些突变并没有降低质子动力或氨基糖苷的摄取,因为野生型和突变株之间的代谢指标或胞内庆大霉素水平没有显著变化。我们全面的蛋白质组学分析揭示了在中期指数生长阶段,突变菌株中与三羧酸(TCA)循环相关的蛋白质的显著上调。表明这些菌株通过增加TCA循环活性以维持其膜电位和ATP水平来补偿其能量代谢的扰动。此外,我们的途径富集分析揭示了在所有突变菌株中显示下调的本地网络簇,它们与大的和小的核糖体结合蛋白有关,核糖体生物发生,翻译因子活动,以及核糖核苷一磷酸的生物合成。这些发现为突变菌株中观察到的氨基糖苷的耐受性提供了合理的解释。总之,这项研究为氨基糖苷耐受的机制提供了有价值的见解,为打击此类细胞的新策略铺平了道路。
对抗生素药物耐药的细菌对全球人类健康构成重大挑战。它们获得了基因突变,使它们能够在一种或多种抗生素的存在下生存和生长,这使得临床医生更难从危及生命的感染患者中消除这种细菌。一些细菌可能能够通过改变它们的生长和行为来暂时发展对抗生素的耐受性,没有获得任何新的基因突变。这种耐药细菌更有可能存活足够长的时间以获得可能促进耐药性的突变。最近的研究表明,参与过程的基因统称为能量代谢,将食物来源转化为细胞生存和生长所需的化学能量,可能在耐受性和抗性方面都起作用。例如,当暴露于称为氨基糖苷类的抗生素家族成员时,大肠杆菌细菌会在能量代谢基因中发生突变。然而,目前尚不清楚能量代谢在抗生素耐受中的确切作用。为了解决这个问题,Shiraliyev和Orman研究了一系列影响能量代谢的具有不同基因突变的大肠杆菌菌株如何在氨基糖苷类药物存在下存活。实验发现,大多数突变菌株对药物的耐受性高于正常大肠杆菌。出乎意料的是,这种增加的耐受性似乎不是由于进入突变细菌细胞的药物比进入正常细胞的药物少(一种常见的耐药性和耐受性策略).使用一种技术进行进一步的实验,被称为蛋白质组学,揭示了许多参与能量代谢的基因在突变细菌中上调,表明这些细胞正在补偿它们的遗传异常。此外,突变细菌的抗生素靶向分子水平低于正常细菌。Shiraliyev和Orman的发现为细菌如何耐受氨基糖苷类抗生素提供了重要见解。在未来,这可能会指导开发新的策略来对抗细菌性疾病。
Aminoglycoside antibiotics target ribosomes and are effective against a wide range of bacteria. Here, we demonstrated that knockout strains related to energy metabolism in Escherichia coli showed increased tolerance to aminoglycosides during the mid-exponential growth phase. Contrary to expectations, these mutations did not reduce the proton motive force or aminoglycoside uptake, as there were no significant changes in metabolic indicators or intracellular gentamicin levels between wild-type and mutant strains. Our comprehensive proteomics analysis unveiled a noteworthy upregulation of proteins linked to the tricarboxylic acid (TCA) cycle in the mutant strains during the mid-exponential growth phase, suggesting that these strains compensate for the perturbation in their energy metabolism by increasing TCA cycle activity to maintain their membrane potential and ATP levels. Furthermore, our pathway enrichment analysis shed light on local network clusters displaying downregulation across all mutant strains, which were associated with both large and small ribosomal binding proteins, ribosome biogenesis, translation factor activity, and the biosynthesis of ribonucleoside monophosphates. These findings offer a plausible explanation for the observed tolerance of aminoglycosides in the mutant strains. Altogether, this research provides valuable insights into the mechanisms of aminoglycoside tolerance, paving the way for novel strategies to combat such cells.
Bacteria that are resistant to antibiotic drugs pose a significant challenge to human health around the globe. They have acquired genetic mutations that allow them to survive and grow in the presence of one or more antibiotics, making it harder for clinicians to eliminate such bacteria from human patients with life-threatening infections. Some bacteria may be able to temporarily develop tolerance to an antibiotic by altering how they grow and behave, without acquiring any new genetic mutations. Such drug-tolerant bacteria are more likely to survive long enough to gain mutations that may promote drug resistance. Recent studies suggest that genes involved in processes collectively known as energy metabolism, which convert food sources into the chemical energy cells need to survive and grow, may play a role in both tolerance and resistance. For example, Escherichia coli bacteria develop mutations in energy metabolism genes when exposed to members of a family of antibiotics known as the aminoglycosides. However, it remains unclear what exact role energy metabolism plays in antibiotic tolerance. To address this question, Shiraliyev and Orman studied how a range of E. coli strains with different genetic mutations affecting energy metabolism could survive in the presence of aminoglycosides. The experiments found that most of the mutant strains had a higher tolerance to the drugs than normal E. coli. Unexpectedly, this increased tolerance did not appear to be due to the drugs entering the mutant bacterium cells less than they enter normal cells (a common strategy of drug resistance and tolerance). Further experiments using a technique, known as proteomics, revealed that many genes involved in energy metabolism were upregulated in the mutant bacteria, suggesting these cells were compensating for the genetic abnormalities they have. Furthermore, the mutant bacteria had lower levels of the molecules the antibiotics target than normal bacteria. The findings of Shiraliyev and Orman offer critical insights into how bacteria become tolerant of aminoglycoside antibiotics. In the future, this may guide the development of new strategies to combat bacterial diseases.