这项研究旨在研究抗菌活性,细胞毒性,和非离子的作用机制,环状脂肽,serrawettinW2-FL10抗金黄色葡萄球菌。W2-FL10对革兰氏阳性细菌金黄色葡萄球菌表现出有效的活性,粪肠球菌,屎肠球菌,单核细胞增生李斯特菌,和枯草芽孢杆菌,最小抑制浓度(MIC)值在6.3至31.3μg/mL范围内,而没有观察到针对革兰氏阴性细菌的活性。肉汤微量稀释试验表明W2-FL10与细胞膜关键成分相互作用,例如金黄色葡萄球菌的脂质磷脂酰甘油和脂磷壁酸。在膜相互作用时,W2-FL10在12分钟内耗散膜电位,在28-40分钟内增加金黄色葡萄球菌膜通透性,尽管速度较慢,浓度高于裂解肽蜂毒素。观察到的膜通透性,用碘化丙啶(PI)检测,可能归因于跨膜孔/病变,可能依赖于膜中二聚体驱动的脂肽寡聚化。扫描电子显微镜(SEM)成像还在视觉上证实了金黄色葡萄球菌菌株之一的细胞壁中病变的形成,暴露于W2-FL10后1小时内的细胞损伤,证实了金黄色葡萄球菌菌株的快速时间杀伤动力学。这种对金黄色葡萄球菌菌株的杀菌作用对应于W2-FL10的膜透化作用,表明自我促进摄取到细胞质中可能是作用模式的一部分。最后,与对照(依米汀)相比,这种脂肽对中国仓鼠卵巢(CHO)细胞系表现出低至中等的细胞毒性,具有最佳的亲脂性范围(logD值为2.5),表明其作为抗生素候选的潜力。
目的:抗菌素耐药性是一个主要的公共卫生问题,迫切需要抗菌化合物表现出低的不良健康影响。在这项研究中,描述了一种新的抗菌脂肽类似物,serrawettinW2-FL10(源自粘质沙雷氏菌),具有针对金黄色葡萄球菌的有效活性。机制研究表明W2-FL10靶向金黄色葡萄球菌的细胞膜,由于跨膜病变/毛孔而导致去极化和透化,导致细胞内成分的泄漏,W2-FL10的可能的细胞溶质摄取,并最终导致细胞死亡。这项研究提供了对非离子脂肽的作用模式的首次了解。W2-FL10的低至中等细胞毒性也突出了其作为治疗细菌感染的有希望的治疗剂的应用。
The study aimed to investigate the antibacterial activity, cytotoxicity, and mechanism of action of the non-ionic, cyclic lipopeptide, serrawettin W2-FL10 against Staphylococcus aureus. W2-FL10 exhibited potent activity against the Gram-positive bacteria S. aureus, Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, and Bacillus subtilis, with minimum inhibitory concentration (MIC) values ranging from 6.3 to 31.3 μg/mL, while no activity was observed against Gram-negative bacteria. Broth microdilution assays showed that W2-FL10 interacted with key cell membrane components, such as lipid phosphatidyl glycerol and lipoteichoic acid of S. aureus. Upon membrane interaction, W2-FL10 dissipated membrane potential within 12 min and increased S. aureus membrane permeability within 28-40 min, albeit at slower rates and higher concentrations than the lytic peptide melittin. The observed membrane permeability, as detected with propidium iodide (PI), may be attributed to transmembrane pores/lesions, possibly dependent on dimer-driven lipopeptide oligomerization in the membrane. Scanning electron microscopy (SEM) imaging also visually confirmed the formation of lesions in the cell wall of one of the S. aureus strains, and cell damage within 1 h of exposure to W2-FL10, corroborating the rapid time-kill kinetics of the S. aureus strains. This bactericidal action against the S. aureus strains corresponded to membrane permeabilization by W2-FL10, indicating that self-promoted uptake into the cytosol may be part of the mode of action. Finally, this lipopeptide exhibited low to moderate cytotoxicity to the Chinese hamster ovarian (CHO) cell line in comparison to the control (emetine) with an optimal lipophilicity range (log D value of 2.5), signifying its potential as an antibiotic candidate.
OBJECTIVE: Antimicrobial resistance is a major public health concern, urgently requiring antibacterial compounds exhibiting low adverse health effects. In this study, a novel antibacterial lipopeptide analog is described, serrawettin W2-FL10 (derived from Serratia marcescens), with potent activity displayed against Staphylococcus aureus. Mechanistic studies revealed that W2-FL10 targets the cell membrane of S. aureus, causing depolarization and permeabilization because of transmembrane lesions/pores, resulting in the leakage of intracellular components, possible cytosolic uptake of W2-FL10, and ultimately cell death. This study provides the first insight into the mode of action of a non-ionic lipopeptide. The low to moderate cytotoxicity of W2-FL10 also highlights its application as a promising therapeutic agent for the treatment of bacterial infections.