Gh Mohammad Sharifian, Wilhelm Michael J, Dai Hai-Lung
Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States.
ACS Med Chem Lett. 2018 Mar 9;9(6):569-574. doi: 10.1021/acsmedchemlett.7b00499. eCollection 2018 Jun 14.
We present a nonlinear light scattering method for monitoring, with real-time resolution and membrane specificity, changes in molecular adsorption, and transport at bacterial membranes induced by an antimicrobial compound. Specifically, time-resolved second-harmonic light scattering (SHS) is used to quantify azithromycin-induced changes to bacterial membrane permeability in colloidal suspensions of living . Variations in membrane properties are monitored through changes in the adsorption and transport rates of malachite green, a hydrophobic cation that gives SHS signal. Regardless of concentration, instantaneous treatment with azithromycin showed no significant changes in membrane permeability. However, 1 h pretreatment with subminimum inhibitory concentrations of azithromycin induced an order-of-magnitude enhancement in the permeability of both the outer membrane and, through facilitation of a new transport mechanism, the cytoplasmic membrane of the bacteria as well. This study illustrates SHS as a novel tool for monitoring antimicrobial-induced changes to membrane properties in living bacteria.
我们提出了一种非线性光散射方法，可实时监测抗菌化合物诱导的细菌膜分子吸附和转运变化，并具有膜特异性。具体而言，时间分辨二次谐波光散射（SHS）用于量化阿奇霉素对活细菌胶体悬浮液中细菌膜通透性的影响。通过监测孔雀石绿（一种能产生SHS信号的疏水性阳离子）吸附和转运速率的变化来监测膜性质的变化。无论浓度如何，阿奇霉素的瞬时处理均未显示膜通透性有显著变化。然而，用亚最小抑菌浓度的阿奇霉素预处理1小时，可使细菌外膜以及通过促进一种新的转运机制使细胞质膜的通透性提高一个数量级。这项研究表明SHS是一种监测抗菌药物诱导的活细菌膜性质变化的新型工具。
