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Journal ArticleDOI

A mechanistic study of the antibacterial effect of silver ions on Escherichia coli and Staphylococcus aureus.

Qing Ling Feng1, J. Wu1, Guo-Qiang Chen1, Fuzhai Cui1, T. N. Kim, J. O. Kim 
15 Dec 2000-Journal of Biomedical Materials Research (J Biomed Mater Res)-Vol. 52, Iss: 4, pp 662-668
TL;DR: 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.
Abstract: 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.
Citations
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Journal ArticleDOI
TL;DR: The results indicate that the bactericidal properties of the nanoparticles are size dependent, since the only nanoparticles that present a direct interaction with the bacteria preferentially have a diameter of approximately 1-10 nm.
Abstract: Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring of materials. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which exhibit increased chemical activity due to their large surface to volume ratios and crystallographic surface structure. The study of bactericidal nanomaterials is particularly timely considering the recent increase of new resistant strains of bacteria to the most potent antibiotics. This has promoted research in the well known activity of silver ions and silver-based compounds, including silver nanoparticles. The present work studies the effect of silver nanoparticles in the range of 1-100 nm on Gram-negative bacteria using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). Our results indicate that the bactericidal properties of the nanoparticles are size dependent, since the only nanoparticles that present a direct interaction with the bacteria preferentially have a diameter of approximately 1-10 nm.

5,609 citations

Journal ArticleDOI
TL;DR: These nontoxic nanomaterials, which can be prepared in a simple and cost-effective manner, may be suitable for the formulation of new types of bactericidal materials.

5,309 citations

Journal ArticleDOI
TL;DR: Silver nanoparticles have emerged up with diverse medical applications ranging from silver based dressings, silver coated medicinal devices, such as nanogels, nanolotions, etc, due to its capability of modulating metals into their nanosize.

5,014 citations


Cites background from "A mechanistic study of the antibact..."

  • ...Also, it has been reported that heavy metals react with proteins by getting attached with the thiol group and the proteins get inactivated (Liau et al., 1997; Feng et al., 2000)....

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  • ...The nanoparticles release silver ions in the bacterial cells, which enhance their bactericidal activity (Feng et al., 2000; Sondi and Salopek-Sondi, 2004; Morones et al., 2005; Song et al., 2006)....

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  • ...Feng et al. (2000) reported mechanistic study of inhibition of silver ions against two strains of bacteria, S. aureus and E. coli....

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  • ...• Treatment of burns and various infections (Feng et al., 2000)....

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Journal ArticleDOI
TL;DR: This is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and the results demonstrate thatsilver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.
Abstract: In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag+ (in the form of AgNO3). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.

3,697 citations


Cites background from "A mechanistic study of the antibact..."

  • ...Reports on the mechanism of inhibitory action of silver ions on microorganisms show that upon Ag treatment, DNA loses its replication ability (10) and expression of ribosomal subunit proteins as well as some other cellular proteins and enzymes FIG....

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Journal ArticleDOI
TL;DR: This review presents an overview of silver nanoparticles (Ag NPs) preparation by green synthesis approaches that have advantages over conventional methods involving chemical agents associated with environmental toxicity.

3,290 citations

References
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Book
01 Jan 1937
TL;DR: The third edition, coming ten years after the first, emphasizes both the flowering of biochemical research and the prodigious effort by busy teachers and scientists to keep up to date this popular text and reference.
Abstract: Principles of biochemistry , Principles of biochemistry , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

5,830 citations

Journal ArticleDOI
S.Y. Liau1, D.C. Read1, W.J. Pugh1, J. R. Furr1, A. D. Russell1 
TL;DR: The results imply that interaction of Ag+ with thiol groups plays an essential role in bacterial inactivation.
Abstract: Microbiologically it was demonstrated that amino acids, e.g. cysteine (CySH), and other compounds, e.g. sodium thioglycollate, containing thiol groups neutralized the activity of silver nitrate against Pseudomonas aeruginosa PAO1. Amino acids with disulphide bonds were inactive, with the exception of L-cystine dimethyl ester, as were all amino acids with no sulphur groups. Iodoacetamide reacted with CySH to produce a CyS-acetamide complex that was unable to quench the activity of Ag+. Chemical analyses using cyclic voltammetry demonstrated that high coordination numbers (3.1) were obtained with thiol-containing amino acids and low numbers (0.28-0.4) with other amino acids. Both microbiologically and chemically, the results imply that interaction of Ag+ with thiol groups plays an essential role in bacterial inactivation.

800 citations

Journal ArticleDOI
TL;DR: There is now a renaissance of topical antibacterial therapy with the introduction of dilute silver nitrate solutions and mafenide-containing ointments, which are effective in burn wound sepsis, especially that caused byP aeruginosa, but both also produce characteristic fluid and electrolyte alterations.
Abstract: AFTER thermal burns local and systemic infection, especially withPseudomonas aeruginosa, is a major cause of death. The use of soluble sodium sulfonamides in wounds and burns was investigated during World War II,1and in studies of extensive burns,2topical antibacterial therapy was combined with treatment for the burn wound by using a neutralized mixture of tannic acid and sodium sulfadiazine. Although the results were good, emphasis shifted to the role of sodium salts in systemic therapy in an era of disbelief in the efficacy of local antibacterial therapy. As predicted in 1952 by Meleney,3there is now a renaissance of topical antibacterial therapy with the introduction of dilute silver nitrate solutions4and mafenide-containing ointments.5Both agents are effective in burn wound sepsis, especially that caused byP aeruginosa, but both also produce characteristic fluid and electrolyte alterations. The hypotonic (29.4 millimol/liter) silver nitrate solution

445 citations