Photoinactivation effects of hematoporphyrin monomethyl ether on Gram-positive and -negative bacteria detected by atomic force microscopy
Photoinactivation effects of hematoporphyrin monomethyl ether on Gram-positive and -negative bacteria detected by atomic force microscopy
复制标题
原子力显微镜检测血卟啉单甲醚对革兰氏阳性菌和阴性菌的光灭活作用
DOI：
10.1007/s00253-010-2747-4
复制
发表时间：
2010-10-01
影响因子：
5
通讯作者：
Cai, Jiye
中科院分区：
文献类型：
--
作者：
Jin, Hua;Huang, Xun;Cai, Jiye
光动力学抗菌化学疗法作为一种有效杀灭病原微生物的方法，正引起人们越来越多的关注。本文研究了血卟啉单甲醚（HMME）对革兰氏阳性菌和革兰氏阴性菌的细胞毒和光毒作用。采用集落形成单位法测定细胞活力，结果表明，在检测浓度范围内，细胞无明显的细胞毒性，但有较高的光毒性。革兰氏阳性菌对HMME的光毒性反应更敏感。同时，利用原子力显微镜（AFM）检测HMME处理前后细菌的形态和纳米力学性质的变化。AFM图像表明，光灭活后，细菌表面从一个光滑，均匀的建筑改变为一个异质的，裂纹形态。力谱测量表明，细胞壁变得不那么刚性和杨氏模量下降约50%，而尖端细胞表面粘附力显着增加相比，那些原生细胞。推测HMME的光动力效应引起外膜化学组成的变化和包膜内某些蛋白质的暴露。原子力显微镜可以作为研究细菌与药物相互作用的一种强大而灵敏的方法。
The photodynamic antimicrobial chemotherapy as a promising approach for efficiently killing pathogenic microbes is attracting increasing interest. In this study, the cytotoxic and phototoxic effects of hematoporphyrin monomethyl ether (HMME) on the Gram-positive and Gram-negative bacteria were investigated. The cell viability was assessed by colony-forming unit method, and the results indicated that there was no significant cytotoxicity but high phototoxicity in the examined concentrations. Notably, the Gram-positive bacteria were more sensitive to HMME in phototoxicity. Simultaneously, an atomic force microscope (AFM) was used to detect the changes in morphological and nanomechanical properties of bacteria before and after HMME treatment. AFM images indicate that upon photoinactivation, the bacterial surface changed from a smooth, homogeneous architecture to a heterogenous, crackled morphology. The force spectroscopy measurements reveal that the cell wall became less rigid and the Young’s modulus decreased about 50%, whereas the tip-cell-surface adhesion forces increased significantly compared to those of native cells. It was speculated that the photodynamic effects of HMME induced the changes in the chemical composition of the outer membrane and exposure of some proteins inside the envelope. AFM can be utilized as a powerful and sensitive method for studying the interaction between bacteria and drugs.