作 者：
;
;
;
;
;
机构地区：
暨南大学生命科学技术学院化学系
出 处：
《现代仪器》
2010年第3期34-38,共5页
摘 要：
目的:探测阿莫西林作用于沙门氏菌(G)和单核增生性李斯特菌(G^+)后2种菌体的形貌和生物力学特性的变化,探讨阿莫西林的抗菌活性和抗菌机理。方法:通过平板菌落计数法测细菌的失活率,利用原子力显微镜(AFM)对药物作用后细菌的表面形貌及细胞的硬度、粘附力做定性和定量分析。结果:平板菌落计数得,25μg/mL的阿莫西林作用1h后,沙门氏菌的失活率较李斯特菌的失活率大。AFM测量显示,与低浓度阿莫西林作用后,沙门细菌表面出现孔洞,而李斯特菌表面出现裂缝,力曲线测量显示,药物作用后针尖和细胞壁之间的粘附力明显增加,而杨氏模量(E)显著降低。结论:结合AFM图像可知形貌与生物力学特性的变化反映细胞壁的变化,细胞壁的成分由均一性变为异质性从而导致细菌的粘附力增加即F_(native)E_(amoxicillin)通过以上分析进一步探讨阿莫西林的杀菌机理和不同的细菌对阿莫西林的敏感程度。这些AFM数据为阿莫西林的临床应用提供可视化的数据支持。
In this paper, atomic force microscope （AFM） was used to study the alterations of morphologi- cal and nanomechanical properties about Gram-negative bacteria Salmonella（Sal.） and Gram-positive bacteria Listeria monocytogenes （Lm） which Were treated with amoxicillin. The results provided available information about the antimicrobial activity and clinical application of amoxicillin. The morphological and biomechanical properties of bacteria before and after treated with different concentrations of amoxicillin were detected by AFM. Simultaneously, the inactivation efficiency of bacteria were investigated by panel colony counting method. AFM images showed that amoxicillin induced pore-like damage to the envelope of Sal.. Comparing to there were cracks on the surface of Lm. The force spectroscopy indicated the adhesion force Fnative〈Famoxicillin and the Young＇s modulus Enative〉E icillin for Sal. and Lm. From the results, Sal. was more sensitive to amoxicillin than that of Lm. The changes in the ultrastructure are correlated to the corresponding changes in the nanomechanical properties of the bacteria cell envelope. The crosslinking peptidoglycan layer was damaged seriously with the increasing concentra- tions of amoxicillin, which lead to the significantly decrease of cell rigidity. However, the tip-cell-surface adhesion force of dead bacteria increased significantly compared to that of native bacteria, it might be caused by the wrecked envelope and the changes in the chemical composition of bacterial outer membrane.
关 键 词：
阿莫西林
沙门氏菌
单核增生性李斯特菌
生物力学特性原子力显微镜
领 域：
[机械工程]
[机械工程]
[机械工程]
