A mechanistic study of the antibacterial effect of silver ions onEscherichia coli andStaphylococcus aureus

Autor: J. O. Kim, Guo-Qiang Chen, T. N. Kim, Qing Ling Feng, J. Wu, Fuzhai Cui
Rok vydání: 2000
Předmět:
Zdroj: Journal of Biomedical Materials Research. 52:662-668
ISSN: 1097-4636
0021-9304
DOI: 10.1002/1097-4636(20001215)52:4<662::aid-jbm10>3.0.co;2-3
Popis: To investigate the mechanism of inhibition of silver ions on microorganisms, two strains of bacteria, namely Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), were treated with AgNO(3) and studied using combined electron microscopy and X-ray microanalysis. Similar morphological changes occurred in both E. coli and S. aureus cells after Ag(+) treatment. The cytoplasm membrane detached from the cell wall. A remarkable electron-light region appeared in the center of the cells, which contained condensed deoxyribonucleic acid (DNA) molecules. There are many small electron-dense granules either surrounding the cell wall or depositing inside the cells. The existence of elements of silver and sulfur in the electron-dense granules and cytoplasm detected by X-ray microanalysis suggested the antibacterial mechanism of silver: DNA lost its replication ability and the protein became inactivated after Ag(+) treatment. The slighter morphological changes of S. aureus compared with E. coli recommended a defense system of S. aureus against the inhibitory effects of Ag(+) ions.
Databáze: OpenAIRE
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