Laskowski Dariusz, Strzelecki Janusz, Pawlak Konrad, Dahm Hanna, Balter Aleksander
Department of Microbiology, Faculty of Biology and Environmental Protection, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
Department of Biophysics and Medical Physics, Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100 Toruń, Poland.
Micron. 2018 Sep;112:84-90. doi: 10.1016/j.micron.2018.05.005. Epub 2018 May 5.
Discovery of new antibacterial agents requires the development of novel techniques for bacteria surface characterization after treatment with antibiotics. In this study, we investigate the effect of ampicillin at MICs levels on adhesive properties of Gram-positive and Gram-negative bacteria, using atomic force microscopy (AFM). Our results revealed that the treatment leads to changes of bacterial surface properties, especially cell surface roughness. A nanomechanical alteration of the cells led to an increase of adhesive forces and rupture lengths. Changes in adhesive properties are determined not only by the modification of physicochemical cell properties but also by an increase in roughness, leading to an increase of the contact area with a cantilever tip. We discovered that the contribution of non-specific physicochemical interactions in the bacteria attachment to a substrate is not negligible and was significantly influenced by the presence of antibiotic. Ampicillin caused much greater change in the adhesion properties of Bacillus subtilis than Escherichia coli due to the mode of action of β-lactam antibiotic. Adhesion measurements may by a new way to investigate subtle changes of the bacterial surface properties caused by antibiotic, especially those targeting the bacterial cell wall. In contrast to nanoindentation assays, they provide information on adhesive properties of the bacteria surface.
发现新型抗菌剂需要开发用于表征抗生素处理后细菌表面特征的新技术。在本研究中，我们使用原子力显微镜（AFM）研究了最低抑菌浓度（MIC）水平的氨苄青霉素对革兰氏阳性菌和革兰氏阴性菌粘附特性的影响。我们的结果表明，该处理导致细菌表面特性发生变化，尤其是细胞表面粗糙度。细胞的纳米力学改变导致粘附力和破裂长度增加。粘附特性的变化不仅由细胞物理化学性质的改变决定，还由粗糙度的增加导致与悬臂尖端接触面积的增加所决定。我们发现，细菌附着于底物时非特异性物理化学相互作用的贡献不可忽略，并且受到抗生素存在的显著影响。由于β-内酰胺抗生素的作用方式，氨苄青霉素对枯草芽孢杆菌粘附特性的影响比对大肠杆菌的影响大得多。粘附测量可能是一种研究抗生素引起的细菌表面特性细微变化的新方法，尤其是那些针对细菌细胞壁的变化。与纳米压痕测定法不同，它们提供了有关细菌表面粘附特性的信息。
