CIPA-Chile, Faculty of Chemistry Sciences, Department of Polymers, Advanced Materials Laboratory, University of Concepcion, Concepcion, Chile.
J Appl Microbiol. 2010 Feb;108(2):633-46. doi: 10.1111/j.1365-2672.2009.04447.x. Epub 2009 Jun 30.
This article investigated the lethal effect and morphological changes on Staphylococcus aureus strains ATCC 25923 and ATCC 6538P produced by chitosan-Ag (I) films as observed by electron microscopy.
The antimicrobial activity of films against staphylococci was determined using the broth dilution method and agar diffusion test. Killing curves, transmission and scanning electron microscopy (TEM and SEM) techniques were employed to evaluate the bacterial death and morphological changes in bacterial cells after exposure to chitosan-Ag (I) films. Films affected the cell structure of Staph. aureus, causing elongation of cells, disaggregation of grape-like cluster, contraction of bacterial cytoplasm, thickening of cell wall, increase in cell wall roughness, cell disruption with loss of intracellular material, filamentation and bacteriolysis, as seen in the micrographs following 3, 6, 12 and 16 h of incubation.
Obtained images clearly show that chitosan-Ag (I) films have a notable antistaphylococcal activity.
Information from this study can be employed in guiding future strategies to improve the design of materials for the food industry packaging.
本文通过电子显微镜观察壳聚糖-银（I）薄膜对金黄色葡萄球菌 ATCC 25923 和 ATCC 6538P 菌株的致死作用和形态变化。
采用肉汤稀释法和琼脂扩散试验测定薄膜对葡萄球菌的抗菌活性。采用杀菌曲线、透射电子显微镜（TEM）和扫描电子显微镜（SEM）技术评价壳聚糖-银（I）薄膜暴露后细菌死亡和细菌细胞形态变化。薄膜影响金黄色葡萄球菌的细胞结构，导致细胞伸长、葡萄球菌簇解聚、细胞质收缩、细胞壁增厚、细胞壁粗糙度增加、细胞内容物丢失、丝状和溶菌，孵育 3、6、12 和 16 小时后的显微照片可见上述变化。
获得的图像清楚地表明壳聚糖-银（I）薄膜具有显著的抗金黄色葡萄球菌活性。
本研究的信息可用于指导未来改善食品工业包装材料设计的策略。
