万古霉素与血卟啉单甲醚对金葡菌作用的AFM观察

AFM-based characterization of morphological changes of Staphylococcus aureus induced by vancomycin and hematoporphvrin monomethyl ether

目的探讨万古霉素(VM)和血卟啉单甲醚(HMME)对金葡菌形态结构的影响及其抗菌作用机制。方法分别用不同浓度的VM和HMME作用于金葡菌,平板菌落计数细菌失活率,并用原子力显微镜(AFM)观察抗菌药作用前后细菌形态结构的变化。结果随着VM浓度的增加,金葡菌失活率增加,细胞高度和表面粗糙度(Ra)增加。当浓度增至20μg/ml,失活率达90%以上,高度和Ra下降,表面出现贯穿整个菌体的裂纹。而金葡萄与HMME孵育光照,随着HMME浓度增大,细菌失活率增大,HMME增至50μg/ml时,失活率达到99%以上,AFM成像显示细胞壁完全破裂。结论两种抗菌药对金葡菌的杀伤位点都是破坏细菌的表面结构。AFM为药物对细菌的敏感性及作用机制的探究提供了形貌上的依据。

Objective To investigate antibacterial effects and cell morphological changes in S. aureus reacted with vancomycin and hematoporphvrin monomethyl ether （HMME）. Methods S. aureus incubated with different concentrations of vancomycin and HMME respectively, and bacterial inactivation efficiency was detected with panel colony counting method and morphological changes were observed with atomic force microscope （AFM）. Results When S. aureus was reacted with vancomycin, with the increased concentrations of vancomycin, the damage extent of S. aureus was also increased. There were cracks on the surface and roughness of the cell were increased as well. While S. aureus was cultured with 50 μg/ml HMME and then irradiated by visible light for 30 minutes, the bacterial inactivation efficiency was over 99% and AFM images showed there were many splits on ihe surface of the cell. Conclusion The results indicated that the mechanisms of S. aureus in cell membrane damages, and AFM provides a visual technique reacted with antimicrobial agents. reacted with vancomycin and HMME were resulted to study the mechnism and sensitivity of bacterial