Antibacterial and Cytotoxic Effects of Silver Nanoparticles on Staphylococcus aureus and Normal Vero Cells (original) (raw)
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Annals of Tropical Medicine and Public Health, 2020
Silver (nanoparticles) (AgNPs) are of special concern as a result of their unique chemical, physical and biological characteristics. It has become an attractive alternative to antibiotics due to their broad-spectrum antimicrobial activity. The study aimed to determine the antibacterial activity of AgNPs against S. aurous bacteria and the effect of AgNPs on the-viability of normal cell line (Vero cell). A1total of 70 clinical 1samples (-wound and vagina swab, stool and urine) were used in this study. Bacterial isolates were subjected to the microscopically, cultural and biochemical evaluation, AgNPs were-prepared and checked for their antimicrobial activity by the use of 1various concentrations employing agar dilution method. In addition, the effect of different concentrations of AgNPs on a viability of Vero cells was examined. The results showed that out of 70 clinical samples, 11 (15.7%) isolates were Staphylococcus aurous. AgNPs showed high activity against S. aurous at concentrations (100 μg/ml and 200μg/ml). It was found that there was no effect of AgNPs on the viability of the normal Vero cells at (≤ 250 μg/ml) concentration, but they have cytotoxic effect on the viability of the these cells at high concentrations. This study concluded that AgNPs possess good antimicrobial-activity and the concentrations that maintain the cell viability could be used as an alternative therapy to treat S. aurous infections.
Biological activity of synthesized silver nanoparticles on S. aureus and P. aeruginosa
Delta Journal of Science
Silver nanoparticles (AgNPs) that were biologically synthesized using Moringa oleifera leave extract showed good antibacterial activity against two tested bacterial strains namely: Pseudomonas aeruginosa as a model for Gram-negative bacteria and Staphylococcus aureus as a model for Gram-positive bacteria. Minimum inhibitory concentration (MIC) of antibacterial silver nanoparticles that were biologically synthesized using Moringa oleifera leave extract was tested to estimate the effect of nanoparticles on cell viability, cell integrity, and cell permeability of tested bacteria. The results indicated that there was a great effect of AgNPs on cell viability of bacterial strains tested as there was significance in cell viability between control and treated bacteria with silver nanoparticles. Also, cell permeability of S. aureus and P. aeruginosa were greatly affected by biologically synthesized silver nanoparticles and statistical analysis revealed that there was significant difference in cell permeability of two tested bacteria between control and treated cells with nanoparticles. However, there were slightly effect of these nanoparticles on cell integrity when the absorbance of DNA was estimated.
Biomaterial Investigations in Dentistry
Aim: To determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of silver nanoparticles against Staphylococcus aureus (S. aureus). Methodology: The antimicrobial efficacy of the silver nanoparticles was determined by the standard methods of Clinical and Laboratory Standards Institute (CLSI). Different concentrations of silver nanoparticles were prepared, and MIC was calculated by tube macro-dilution method. The MBC was determined by the lowest concentration that kills 99.9% of the initial bacterial population. The data were analyzed by ANOVA and Tukey's post hoc test using SPSS software. Results: The MIC and MBC of silver nanoparticles against S. aureus was found to be 0.625 mg/ml. Conclusion: The result obtained from this study shows that silver nanoparticles have potential bactericidal effects against S. aureus at a concentration of 0.625 mg/ml. Silver nanoparticles can be incorporated in the root canal medicaments, sealers and irrigants as it possess potent antimicrobial efficacy against S. aureus.
EVALUATION OF ANTIBACTERIAL BEHAVIOUR OF SILVER NANOPARTICLES.
It is well known that Silver nanoparticles has great affinity against many pathogenic microbes i.e silver nanoparticles possess good antimicrobial properties against many bacteria and fungi. Staphylococcus aureus is one of the most pathogenic bacteria causing infections on skin, respiratory tract, not only this it also cause life threatening diseases such as pneumonia, meningitis etc. Inhibitory effect of silver nanoparticles against staphylococcus aureus gram positive bacteria was evaluated by in-vitro disc diffusion method.The bacterial strains were treated with silver nanoparticle discs at varying concentrations. The antibacterial activity was evaluated by measuring zone of inhibition around antimicrobial disc.
Antibacterial effect of silver nanoparticles on Staphylococcus aureus
Research in Microbiology, 2011
The purpose of this study was to investigate the antibacterial effect of silver nanoparticles in chitosan-poly(ethylene glycol) suspension. The silver nanoparticles (AgNPs) were prepared by use of an environmentally benign method from chitosan (Cts) and poly(ethylene glycol) (PEG) at moderate temperature and with stirring for different times. Silver nitrate (AgNO 3 ) was used as the metal precursor and Cts and PEG were used as solid support and polymeric stabilizer, respectively. The antibacterial activity of silver-chitosan-poly(ethylene glycol) nanocomposites (Ag-Cts-PEG NCs) against Staphylococcus aureus, Micrococcus luteum, Pseudomonas aeruginosa, and Escherichia coli was tested by use of the Mueller-Hinton agar disk-diffusion method. Formation of AgNPs was determined by UV-visible spectroscopy; surface plasmon absorption maxima were observed at 415-430 nm in the UV-visible spectrum. The peaks in the XRD pattern confirmed that the AgNPs had a face-centered cubic structure; peaks of contaminated crystalline phases were not observed. Transmission electron microscopy (TEM) revealed that the AgNPs synthesized were spherical. The optimum stirring time for synthesis of the smallest particle size (mean diameter 5.50 nm) was 12 h. The AgNPs in Cts-PEG were effective against all the bacteria tested. Higher antibacterial activity was observed for AgNPs with smaller size. These results suggest that AgNPs can be used as an effective inhibitor of bacteria and can be used in medical applications. These results also suggest that AgNPs were successfully synthesized in Cts-PEG suspension at moderate temperature with different stirring times.
Abstract In recent years, skin and soft-tissue infections (SSTIs), particularly due to multidrug-resistant pathogens areincreasingly being encountered in clinical settings. Due to the development of antibiotic resistance and theoutbreak of infectious diseases caused by resistant pathogenic bacteria, the pharmaceutical companies and theresearchers are now searching for new unconventional antibacterial agents. Recently, in this fieldnanotechnology represents a modern and innovative approach to develop new formulations based on metallicnanoparticles with antimicrobial properties. The bacterial growth curve, minimum inhibitory concentration (MIC),and minimum bactericidal concentration (MBC) of silver nanoparticles (Ag-NPs) towards Staphylococcus aureusATCC25923, methicillin-sensitive S. aureus (MSSA), and methicillin-resistant S. aureus (MRSA) were examinedin this study. The experiment results showed that the lowest MIC and MBC of Ag-NPs to MRSA was 12.5 μg/mland 25 μg/ml, respectively....
2021
ABSTRACTAntibacterial activity of biosynthesized silver nanoparticles was studied using the macrobroth dilution technique. The silver nanoparticles was significantly active (p > 0.05) against the test organisms at an extract concentration of 75 µg/ml. Concentrations ≤ 50 µg/ml were not as effective as the colony forming units at this concentration, 1.61 × 106 for methicillin-resistant Staphylococcus aureus and concentrations ≤ 25 µg/ml 1.45 × 106 for Pseudomonas aeruginosa respectively, were about the same range as the colony forming units of the controls. The silver nanoparticles inhibited Methicillin-Resistant S. aureus more (MIC of 75 µg/ml and MBC of 100 µg/ml) than they inhibited P. aeruginosa (both MIC and MBC was 100 µg/ml). The LD50 of the synthesized silver nanoparticles after oral administration was seen to be greater than 5000 mg/kg body weight and is therefore thought to be safe. This study supports the use of silver nanoparticles as therapeutic agents.
Effect of a Silver Nanoparticles Solution on Staphylococcus aureus and Candida spp
Journal of Nanomaterials, 2014
An AgNPs solution was synthesized by chemical reduction, characterized, and tested against Candida glabrata, Candida tropicalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). Minimum inhibitory (MICs) and minimum fungicidal/bactericidal concentrations (MFC/MBC) were determined on planktonic cells. Also, total biofilm mass was determined by crystal violet (CV) staining and morphological changes by scanning electron microscope (SEM). MICs for C. glabrata, C. tropicalis, S. aureus, and MRSA were 15.63, 3.91, 1.95, and 1.95 g/mL, respectively. MFC for C. glabrata was 62.5 g/mL and for C. tropicalis 15.63 g/mL The same MBC (3.91 g/mL) was observed for S. aureus and MRSA. CV assay showed that the AgNPs (1000 g/mL) promoted reductions in biofilm mass of ∼60% for C. glabrata and ∼35% for C. tropicalis. A reduction of ∼20% in C. tropicalis biomass was also observed at the concentration of 3.91 g/mL. No significant effect on total biomass was found for S. aureus and MRSA. SEM images revealed that C. glabrata and C. tropicalis biofilm cells, exposed to the AgNPs (1000 g/mL), had an irregular and shriveled appearance. AgNPs solution exhibited considerable antimicrobial activity against important fungal and bacterial pathogens, associated with several oral and systemic diseases, and has potential as an antimicrobial agent.
Nanotoxicology, 2011
Silver nanoparticles (Ag-nps) are used as a natural biocide to prevent undesired bacterial growth in clothing and cosmetics. The objective of this study was to assess the antibacterial efficacy of Ag-nps of different sizes, surface conditions, and synthesis methods against Escherichia coli, Ag-resistant E. coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Salmonella sp. Ag-nps samples were synthesized by: Base reduction with unmodified surfaces and used as synthesized ('unwashed'; 20, 50 and 80 nm) or after 20 phosphate buffer washes ('washed'; 20, 50 and 80 nm), or synthesized by laser ablation with carbon-stabilized surfaces ('carbon-coated'; 25 and 35 nm). Unwashed Ag-nps were toxic to all bacterial strains at concentrations between 3.0-8.0 mg/ml. The washed Ag-nps and carbon-coated Ag-nps were toxic to all bacterial strains except Ag-resistant E. coli at concentrations between 64.0-1024.0 mg/ml. Ag-resistant E. coli died only when treated with unwashed Ag-nps or its supernatant, both of which contained formaldehyde.
Antimicrobial effects of silver nanoparticles
Nanomedicine: Nanotechnology, Biology and Medicine, 2007
The antimicrobial effects of silver (Ag) ion or salts are well known, but the effects of Ag nanoparticles on microorganisms and antimicrobial mechanism have not been revealed clearly. Stable Ag nanoparticles were prepared and their shape and size distribution characterized by particle characterizer and transmission electron microscopic study. The antimicrobial activity of Ag nanoparticles was investigated against yeast, Escherichia coli, and Staphylococcus aureus. In these tests, Muller Hinton agar plates were used and Ag nanoparticles of various concentrations were supplemented in liquid systems. As results, yeast and E. coli were inhibited at the low concentration of Ag nanoparticles, whereas the growth-inhibitory effects on S. aureus were mild. The free-radical generation effect of Ag nanoparticles on microbial growth inhibition was investigated by electron spin resonance spectroscopy. These results suggest that Ag nanoparticles can be used as effective growth inhibitors in various microorganisms, making them applicable to diverse medical devices and antimicrobial control systems.