Abstract:
Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.
摘要:
多药耐药(MDR)细菌引起的感染已成为全球医疗保健系统的主要挑战。在对抗MDR细菌的斗争中,从植物中寻找抗菌化合物受到越来越多的关注。作为一种药用和食用植物,LophatherumgracileBrongn.(L.gracile)具有良好的抗菌作用。然而,主要抗菌活性化合物及其抗菌机理尚不清楚。这里,我们的研究首先确定了来自L.gracile的关键活性化合物为木犀草素。同时,采用肉汤微量稀释法和时间-杀灭曲线分析法检测木犀草素的抑菌效果。木犀草素还可引起形态结构退化和内容物渗漏,细胞壁/膜损伤,ATP合成减少,多药耐药大肠杆菌(MDRE.coli)中磺胺类和喹诺酮类耐药基因的mRNA表达水平下调。此外,基于非靶向UPLC/Q-TOF-MS的细菌代谢产物代谢组学分析显示木犀草素显著改变了核黄素的能量代谢,MDR大肠杆菌的细菌趋化细胞过程和甘油磷脂代谢。这项研究表明木犀草素可能是一种潜在的新型食品添加剂或防腐剂,用于控制MDR大肠杆菌的感染和传播。