The study of antimicrobial activity and preservative effects of nanosilver ingredient

Strain specificity in antimicrobial activity of silver and copper nanoparticles

“…Siva Kumar et al [13] proposed that oxygen associates with silver and reacts with the sulfhydryl (-S-H) groups on cell wall to form R-S-S-R bonds thus, blocking respiration and causing death of cells. Cho et al [15] reported that the surface of the cell walls of E. coli treated with silver nanoparticles were severely damaged compared to untreated E. coli. Cell wall rupture due to silver ions and silver nanoparticles was reported by Lok et al [33].…”

“…The antimicrobial properties of silver nanoparticles are well-established [12][13][14][15] and several mechanisms for their bactericidal effects have been proposed. Although only a few studies have reported the antibacterial properties of copper nanoparticles, they show copper nanoparticles have a significant promise as bactericidal agent [16].…”

“…Although only a few studies have reported the antibacterial properties of copper nanoparticles, they show copper nanoparticles have a significant promise as bactericidal agent [16]. However, other nanoparticles, such as platinum, gold, iron oxide, silica and its oxides, and nickel have not shown bactericidal effects in studies with Escherichia coli [15,17,18]. Yoon et al [19] reported the antibacterial effects of silver and copper nanoparticles using single representative strains of E. coli and Bacillus subtilis, where the copper nanoparticles demonstrated superior antibacterial activity compared to the silver nanoparticles.…”

“…Silver and copper nanoparticles supported on various suitable materials, such as carbon, polyurethane foam, polymers and sepiolite have also been effectively used for bactericidal applications [13,14,[20][21][22]. While various hypotheses have been proposed to explain the mechanism of antimicrobial activity of silver nanoparticles, it is widely believed that silver nanoparticles are incorporated in the cell membrane, which causes leakage of intracellular substances and eventually causes cell death [12,15]. Some of the silver nanoparticles also penetrate into the cells.…”

“…In studies with gram negative, E. coli, and gram positive, Staphylococcus aureus, Kim et al [2] reported greater biocidal efficiency of silver nanoparticles for E. coli, and attributed it to difference in cell wall structure between gram negative and gram positive microorganisms. However, currently there is insufficient evidence to support such conclusions since most research on bactericidal effect of nanoparticles has been conducted with one or a very limited number of microbial strains [12][13][14][15].…”