Abstract:
Membrane potential is a useful marker for antimicrobial susceptibility testing (AST) due to its fundamental roles in cell function. However, the difficulties associated with measuring the membrane potential in microbes restrict its broad application. In this study, we present bioelectrical AST (BeAST) using the model fungus Saccharomyces cerevisiae. Using fluorescent indicators [DiBAC4(3), ThT, and TMRM], we measured plasma and mitochondrial membrane-potential dynamics upon electric stimulation. We find that a 2.5 second electric stimulation induces hyperpolarization of plasma membrane lasting 20 minutes in vital S. cerevisiae, but depolarization in inhibited cells. The numerical simulation of FitzHugh-Nagumo model successfully recapitulates vitality-dependent dynamics. The model also suggests that the magnitude of plasma-membrane potential dynamics (PMD) correlates with the degree of inhibition. To test this prediction and to examine if BeAST can be used for assessing novel anti-fungal compounds, we treat cells with biogenic silver nanoparticles (bioAgNPs) synthesized using orange fruit flavonoids and Fusarium oxysporum. Comparing BeAST with optical density assay alongside various stressors, we show that PMD correlates with the magnitude of growth inhibitions. These results suggest that BeAST holds promise for screening anti-fungal compounds, offering a valuable approach to tackling antimicrobial resistance.
OBJECTIVE: Rapid assessment of the efficacy of antimicrobials is important for optimizing treatments, avoiding misuse and facilitating the screening of new antimicrobials. The need for rapid antimicrobial susceptibility testing (AST) is growing with the rise of antimicrobial resistance. Here, we present bioelectrical AST (BeAST). Combining time-lapse microscopy and mathematical modeling, we show that electrically induced membrane potential dynamics of yeast cells correspond to the strength of growth inhibition. Furthermore, we demonstrate the utility of BeAST for assessing antimicrobial activities of novel compounds using biogenic silver nanoparticles.
摘要:
由于其在细胞功能中的基本作用,膜电位是抗微生物敏感性测试(AST)的有用标记。然而,与测量微生物膜电位相关的困难限制了其广泛应用。在这项研究中,我们使用模型真菌酿酒酵母介绍了生物电AST(BeAST)。使用荧光指示剂[DiBAC4(3),ThT,和TMRM],我们测量了电刺激后的血浆和线粒体膜电位动力学。我们发现,2.5秒的电刺激在重要的酿酒酵母中诱导质膜超极化持续20分钟,但抑制细胞的去极化。FitzHugh-Nagumo模型的数值模拟成功地概括了依赖于活力的动力学。该模型还表明,血浆膜电位动力学(PMD)的大小与抑制程度相关。为了测试这一预测并检查BeAST是否可用于评估新型抗真菌化合物,我们用橙色水果类黄酮和尖孢镰刀菌合成的生物银纳米颗粒(bioAgNPs)处理细胞。将BeAST与光密度测定以及各种应激源进行比较,我们表明PMD与生长抑制的程度相关。这些结果表明,BeAST有望筛选抗真菌化合物,提供了一种有价值的方法来解决抗菌素耐药性。
目的:快速评估抗菌药物的疗效对于优化治疗方案非常重要,避免滥用和促进新抗菌药物的筛选。随着抗生素耐药性的增加,对快速抗生素敏感性测试(AST)的需求也在增长。这里,我们提出了生物电AST(野兽)。结合延时显微镜和数学建模,我们表明,电诱导的膜电位动力学的酵母细胞对应的生长抑制强度。此外,我们证明了BeAST用于使用生物银纳米颗粒评估新型化合物的抗菌活性的实用性。