AI 中文总结
本研究利用SiNWFET传感器监测大肠杆菌对氨苄青霉素的代谢反应，发现AMP致死性与ATP动态和甲酸盐分泌相关，确定甲酸盐代谢为AMP杀菌活性关键通路，证实SiNWFET传感器可用于抗菌相关研究。
AI 中文摘要
抗生素的杀菌作用常被归因于对特定细胞靶点的抑制，但代谢过程会强烈影响药物的疗效。然而，代谢反应与抗生素致死性之间的关系仍未被完全理解。本研究使用硅纳米线场效应晶体管（SiNWFET）传感器实时监测大肠杆菌对氨苄青霉素（AMP）的代谢反应。AMP处理诱导了双相细胞外pH特征，表现为快速酸化后发生碱化。代谢组学分析显示，初始酸化源于有机酸分泌，而后续碱化与氨基酸代谢和甲酸盐通量改变相关。通过代谢和呼吸突变体研究发现，这些细胞外特征反映了通路特异性的代谢重编程，可预测细菌的杀伤效果。AMP的致死性与ATP动态变化和甲酸盐分泌密切相关：AMP诱导ATP增加幅度更大且甲酸盐分泌更多的菌株，其敏感性更强。与文献报道不同，NADH和NADPH水平的变化不支持氧化应激是细菌杀伤的主要机制。综上，本研究确定甲酸盐代谢是与AMP杀菌活性相关的ATP水平升高的关键通路。结果表明，SiNWFET传感器为探究抗生素机制、快速评估细菌敏感性及潜在指导抗菌治疗开发提供了通用的无标记工具。
英文摘要
Antibiotic killing is often attributed to inhibition of specific cellular targets, yet metabolic processes can strongly influence drug efficacy. However, the relationship between metabolic responses and antibiotic lethality remains incompletely understood. Here, we employed silicon nanowire field-effect transistor (SiNWFET) sensors to monitor real-time metabolic responses of Escherichia coli to ampicillin (AMP). AMP treatment induced a biphasic extracellular pH signature, characterized by rapid acidification followed by alkalization. Metabolomic analyses revealed that the initial acidification resulted from organic acid secretion, whereas the subsequent alkalization was associated with altered amino acid metabolism and formate flux. Using metabolic and respiratory mutants, we found that these extracellular signatures reflected pathway-specific metabolic rewiring that predicted bacterial killing. AMP lethality strongly correlated with ATP dynamics and formate secretion: strains exhibiting larger AMP-induced ATP increases and greater formate secretion showed enhanced susceptibility. In contrast to literature, changes in NADH and NADPH levels did not support redox stress as the primary bacterial-killing mechanism. Together, our findings identify formate metabolism as a key pathway underlying the elevated ATP levels associated with AMP bactericidal activity. These results demonstrate that SiNWFET sensors provide a versatile label-free tool for probing antibiotic mechanisms, rapidly assessing bacterial susceptibility, and potentially guiding antimicrobial therapy development.
