Antimicrobial Effect Of Silver Research Articles

Antimicrobial effect of silver and gold nanoparticles in combination with linezolid on Enterococcus biofilm.

In the past few years, application of new antimicrobial e.g. nanoparticles (NPs) to treat infection caused by drug-resistant bacteria has increased. This study aimed to determine antimicrobial property of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) in combination with linezolid on Enterococcus biofilm. A total of forty-eight isolates of Enterococcus spp. were collected and confirmed by PCR method. The synthesis of biocompatible AgNPs was performed, then analyzed by Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy. We carried out minimum inhibitory concentration (MIC) and biofilm forming capacity of AgNPs and AuNPs with linezolid. Twenty-two E. faecium isolates and twentysix E. faecalis investigated in this study. Strong biofilm formation was seen in 12 (25%) of isolates, and others isolates (75%) formed moderate biofilm. AgNPs and Au-NPs size were 26 nm and 20 nm respectively. The MIC of AgNPs was 23.2 μg/ml, and AuNPs were 92.1 μg/ml and the lowest MIC was obtained 2 μg/ml in linezolid. Biofilm formation inhibitory activity by AuNPs + Linezolide and AgNPs + Linezolide 70 to 80 percent increased in average. The antibiofilm activity of AgNPs and AuNPs increased when both agents were used in combination with linezolid in comparison with each agent alone.

Silver Nanoparticles Synthesized Using Eichhornia crassipes Extract from Yuriria Lagoon, and the Perspective for Application as Antimicrobial Agent

The antimicrobial effects of silver (Ag) ions and salts are well known. However, the antimicrobial effects, mechanism, and the cytotoxic activity in vitro of Ag nanoparticles (AgNP) has recently been validated. In this work, we report the green synthesis of AgNPs using the extract of Eichhornia crassipes as a reducing agent and evaluate its antimicrobial activity against Escherichia coli (ATCC-25922). The morphology, size, chemical composition, and inhibition properties of the nanoparticles as a function of the reduction time and temperature were analyzed. According to TEM imaging, nanoparticles with average diameters between 20–40 nm were synthesized. Antibacterial results suggest that AgNPs can be used as an effective growth inhibitor with higher antimicrobial activity against Escherichia coli after 120 min of reaction with a synthesis temperature of 95°. More extensive analysis is required for the appropriate selection of the synthesis parameters and adequate concentration for use in biomedical applications and antibacterial control systems.

The effectiveness of antibacterial therapeutic clothing based on silver or chitosan as compared with non-antibacterial therapeutic clothing in patients with moderate to severe atopic dermatitis (ABC trial): study protocol for a pragmatic randomized controlled trial

BackgroundAtopic dermatitis (AD) is a chronic inflammatory skin disease that affects 10 to 20% of children and between 2 and 15% of the adults in Western Europe. Since 2000, therapeutic clothing or functional textiles based on silver or chitosan as antibacterial agents were introduced for AD. These agents aim to reduce skin colonization with Staphylococcus (S.) aureus. Increased colonization with S. aureus is correlated with increased AD severity. The antimicrobial effects of silver and chitosan have been demonstrated before. At this point, there is insufficient evidence for the effectiveness of antibacterial therapeutic clothing in patients with AD.MethodsThis is a pragmatic randomized controlled double-blind multi-center trial comparing the effectiveness of antibacterial therapeutic clothing based on silver or chitosan as compared with non-antibacterial therapeutic clothing in patients with moderate to severe AD. A total of 165 participants, aged 0 to 80, diagnosed with moderate to severe AD are included. The study is performed in the Erasmus MC University Medical Center, University Medical Center Groningen, University Medical Center Utrecht, Amsterdam University Medical Centers, and St. Antonius Hospital Nieuwegein. Patients will be randomized 1:1:1 into one of the three intervention groups: group A will receive therapeutic clothing without antimicrobial agents, group B will receive microbial growth reducing therapeutic clothing based on chitosan, and group C will receive antimicrobial clothing based on silver. All therapeutic clothing is to be worn at night during the 12-month intervention period. Usual care is continued. The primary objective is to assess the effectiveness of antibacterial clothing (silver and chitosan group) as compared to non-antibacterial clothing assessed with the Eczema Area and Severity Index at 12 months compared to baseline. Secondary outcomes include between-group differences in physician- and patient-reported outcome measures, topical therapy use, S. aureus skin colonization, and safety. Data will be collected at baseline and after 1 month, 3 months, 6 months, and 12 months. A cost-effectiveness analysis will be performed.DiscussionThis trial will provide data on the effectiveness, cost-effectiveness, and safety of antibacterial therapeutic clothing for patients with AD.Trial registrationClinicalTrials.gov NCT04297215. Registered on 5 March 2020

Antimicrobial Effect of Silver Ionised Water Prepared with the Sintering Coating Method—Effect on Acid Production in Plaque

Purpose: To investigate the effect of silver ionised water on acid production in plaque. Methods: After injecting 0.5 mL of silver ionised water (concentration: 5 ppm) produced with the sintering coating method in the sensor part of the pH metre, plaque collected from the oral cavity by one platinum loop was mixed in. Immediately after that, a 5% sucrose solution (1 g/20 mL) was added and the pH was continuously measured for 30 minutes at 1-minute intervals (A). Similarly, silver ionised water was mixed with 5% sucrose solution in the same way as in (A) at 3 (B), 5 (C), 10 (D) and 15 minutes (E) after plaque contamination. The pH was measured at 1-minute intervals. The pH of the purified water containing no silver ionised water mixed with plaque and sugar solution at the same time was measured and used as a control. Each experiment was conducted three times, and the pH measured every minute was compared as a percentage of the pH at the beginning of the measurement (100%). Results: Analysis of variance of the repeated measurements to determine the effect of silver ionised water on the decrease in pH revealed a main effect of silver ionised water and an interaction between time and group [F(1.302,20.826) = 39.145, p < 0.01]. Multiple comparisons using Dunnett’s method showed a significant decline in the rate of decrease in pH from B to E as compared with that in the control (p < 0.01). Conclusion: Silver ionised water was found to inhibit the acid production in plaque.

Antibacterial Effect of Silver-Titanium Bimetallic Nano-Materials

In order to study the antimicrobial effect of silver - titanium bimetallic nano-materials, in this study, through the preparation of TiO2 particles, then using the photoprecipitation method, TiO2/Ag composite materials are synthesized, and finally the core-shell structure of TiO2-Ag nano-composite materials are prepared. The prepared nano-materials are characterized and analyzed. Common Escherichia coli and Staphylococcus aureus are used to evaluate their antimicrobial properties. The results show that there is a maximum absorption peak at 335 nm for TiO2 particles, and the ultraviolet absorption spectra of TiO2/Ag composites and core-shell structure of TiO2-Ag nano-composites change unevenly. The stability of core-shell nano-composites of TiO2-Ag is good and its optical properties are better than expected. The appearance characterization of the prepared nano-materials is analyzed. It is found that the appearance of the prepared nano-materials is basically uniform, and the Ag ions in the core-shell structure of the nano-composites are well dispersed, uniform in size and ideal in effect. In X-ray diffraction analysis, it is found that there are four additional peaks in the TiO2/Ag composite and core-shell structure of the TiO2-Ag nano-composites compared with the TiO2. This is due to the fusion of Ag particles and the fact that Ag particles are not oxidized in the process of ultraviolet irradiation. In the analysis of the antimicrobial properties of the prepared nano-materials, it is found that the antimicrobial effect is most obvious when the reaction time is 45 min, the reaction temperature is 20 °C and the pH of the system is 6. Therefore, through this study, it is found that the antibacterial properties of nano-materials prepared by silver-titanium bimetallic fusion have obvious effect, which reaches the expectation of this study. Although there are some shortcomings in the research process, it still provides experimental basis for the later period of nano-materials with antimicrobial properties, and has important research significance.

Design of Novel Perovskite-Based Polymeric Poly(l-Lactide-Co-Glycolide) Nanofibers with Anti-Microbial Properties for Tissue Engineering.

There is a growing need for anti-microbial materials in several biomedical application areas, such are hernia, skin grafts as well as gynecological products, owing to the complications caused by infection due to surgical biomaterials. The anti-microbial effects of silver in the form of nanoparticles, although effective, can be toxic to surrounding cells. In this study, we report, for the first time, a novel biomedical application of Ag0.3Na1.7La2Ti3O10-layered perovskite particles, blended with poly(L-lactide-co-glycolide) (PLGA), aimed at designing anti-microbial and tissue engineering scaffolds. The perovskite was incorporated in three concentrations of 1, 5, 10 and 15 w/w% and electrospun using dimethylformamide (DMF) and chloroform. The morphology of the resultant nanofibers revealed fiber diameters in the range of 408 to 610 nm by scanning electron microscopy. Mechanical properties of perovskite-based nanofibers also matched similar mechanical properties to human skin. We observed impressive anti-microbial activity, against Gram-negative, Gram-positive bacteria and even fungi, to Ag0.3Na1.7La2Ti3O10 in powder as well as nanofiber-incorporated forms. Furthermore, cytotoxicity assay and immunocytochemistry revealed that perovskite-based nanofibers promoted the proliferation of human dermal fibroblasts whist maintaining normal cellular protein expression. Our study shows that perovskite-nanofibers have potential as scaffolds for biomedical applications with anti-microbial needs.

Characterization of Silver Nanoparticles Obtained by a Green Route and Their Evaluation in the Bacterium of Pseudomonas aeruginosa

Metal nanoparticles are widely used in different areas such as biotechnology and biomedicine, for example in drug delivery, imaging and control of bacterial growth. The antimicrobial effect of silver has been identified as an alternative approach to the increasing bacterial resistance to antibiotics. Silver nanoparticles were synthesized by the green route using the Geranium extract as a reducing agent. The characterization was carried out by the techniques of UV-Vis spectrophotometry, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray emitted photoelectron spectroscopy (XPS) and X-ray diffraction. Nanoparticle diameters between 15 and 50 nm were obtained and the interplanar spaces calculated from the electron diffraction pattern corresponding to a mixture of silver with 4H and FCC structures. To determine the minimum inhibitory concentration of silver nanoparticles (AgNPs) on the Pseudomonas aeruginosa bacteria (ATCC-27853), different concentrations of colloidal solution 0.36, 0.18, 0.09 and 0.05 μg/mL were evaluated as a function of the incubation time, measuring the inhibition halo and colony forming unit (CFU) during 0, 2 and 4 h of incubation. The minimum inhibitory AgNPs concentration (MIC) is 0.36 μg/mL at 0 h while the concentration of 0.18 μg/mL presents a total inhibition of the bacterium after 2 h. For the rest of the dilutions, gradual inhibitions as a function of time were observed. We evaluate the antibacterial effect of silver nanoparticles obtained by a green methodology in Pseudomonas aeruginosa bacteria. Finally, the colloidal nanoparticle solution can be an antibacterial alternative for different biomedical approaches.

Silver-coated magnetic nanocomposites induce growth inhibition and protein changes in foodborne bacteria

Cytotoxicity concerns of nanoparticles on animal or human bodies have led to the design of iron oxide core nanocomposites, coated with elemental silver to allow their magnetic removal from bio-mixtures. Although the antimicrobial effect of silver is well-described, the effects of nanoparticles derived from silver on microorganisms remain unfolded. Here, we characterized a customized magnetic silver nanocomposite (Ag-MNP) and evaluated its effects on bacterial growth and protein changes. The Ag-MNP displayed both longitudinal and round shapes under High-Resolution Transmission Electron Microscopy imaging, while the Energy Dispersive X-ray Spectroscopy and X-ray diffraction analysis confirmed the presence of Ag, Fe3O4 (Magnetite) and FeO2 (Goethite). Optical density, bioluminescence imaging, and Colony Forming Unit assessments revealed that the presence of Ag-MNP induced strong dose-dependent bacteria (Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium and S. Anatum) growth inhibition. The TEM imaging showed penetration and infiltration of bacteria by Ag-MNP, leading to membrane degeneration and vacuole formation. The presence of Ag-MNP led to fifteen up-regulated and nine down-regulated proteins (P < 0.05) that are involved in cell membrane synthesis, inhibition of protein synthesis, interference with DNA synthesis, and energy metabolism inhibition. This study provides insights to develop alternative antimicrobials to treat foodborne pathogens with antibiotic resistance avoidance.

Antimicrobial Effects of Silver(I) and Bismuth(III) Complexes with Secnidazole‑Derived Schiff Base Ligands: the Role of the Nitro Group Reduction

[Ag(HL)NO3] complexes (1-4) were obtained with (E)-N’-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)acetohydrazide (HL1); (E)-N’-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)benzohydrazide (HL2); (E)-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL3) and (E)-N-methyl-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL4) secnidazole-derived Schiff bases. In addition, complexes [Bi(HL3)Cl3] (5) and [Bi(HL4)Cl3] (6) were also prepared. The silver(I) complexes (1-4) showed antifungal activity against Candida fungal strains while the uncomplexed ligands and the bismuth(III) complexes (5-6) were inactive, suggesting that the antifungal effects are probably due to the presence of silver. Although the Schiff base ligands and complexes (1-6) revealed to be inactive against Gram-positive and Gram-negative aerobic bacteria, all compounds exhibited potent antimicrobial effects against several anaerobic bacterial strains, indicating that their mode of action probably involves anaerobic bio reduction of the nitro group, with formation of metabolites which are toxic to the microorganisms. Electrochemistry studies showed that bio reduction of the nitro group is favored in complexes (1-6) in comparison to the free ligands, which might, at least in part, explain their increased antimicrobial effects.

Microbicidal Power of Silver Nano Particles and Its Benefit in Soft Liner Obturator Prosthesis

Background : Indeed growth of some microorganisms, such as Candida and bacteria like Staphylococcus, Streptococcus, and Klebsiella on the soft liner obturator prosthesis has been demonstrated. Microbial colonisation on acrylic appliances represents a challenge for the scientific community to develop new bioactive compounds. Objectives: To achieve this aim, one solution is application of silver nano particles (SNPs) and detects its antimicrobial activity. Silver release from acrylic resins containing silver nano particles is more effective than using silver in micrometer dimensions. Methodology : Purification of bacterial culture and preparation of inoculums (10 5 cfu/ml) for seven clinical human isolates: E. coli, K. pneumoniae, Staphylococcus aureus, strptococcus pyogenes, strptococcus mutans, Enterococcus fecalis and finally candida albicans. Solutions of SNPs and five antimicrobials ( penicillin G, Tetracyclin, Cefoperazone, Ofloxacin and amphotricin B) were prepared in eleven different ppms concentrations as the following; 30 ppm, 15 ppm, 10 ppm, 7.5 ppm, 5 ppm, 3.75 ppm, 2.5 ppm, 1.875 ppm, 1.25 ppm, 0.625 and 0.313. The MICs and the MBCs were detected for all the antimicrobials and compared with those of SNPs. Also antimicrobial susceptibility testing was performed by the disk diffusion method using impregnated disks with 10ppm of SNPs solution which were placed on inoculated agar with E. coli and S. aureus and the inhibition zones were measured and reported. Antimicrobial effect of silver inside the soft relining acrylic was tested by preparing acrostone soft relining acrylic with silver (12ppm) and another silver free preparation was used as a control. Results : The MIC and MBC of the silver were less than those of most antibiotics except those for Ofloxacin which showed less MIC and MBC for both gram positive and gram negative. Gram positive organisms were more resistant to silver than gram negative. The growth inhibition zones by the disk diffusion method were 8 and 6 mm for S. aureus and E. coli, respectively. The free silver preparation showed microbial growth after 24 hours of incubation unlike the silver preparation. The silver protected the soft relining acrylic from bacterial and fungal growths tell the 10th week and produced a safety zone of inhibition around it. Conclusions : SNPs showed a respectable antimicrobial effect with low MIC and MBC and it seems that using SNPs in acrylic resins protects the preparation from bacterial and fungal growth inside, adhesion to its surface, and made a safety zone around it and If we put in consider the mechanical hygiene of the mouth we expect a better results.

Effect of citrate coated silver nanoparticles on biofilm degradation in drinking water PVC pipelines

Citrate ion is a commonly used reductant in metal colloid synthesis, undergoes strong surface interaction with silver nanocrystallites. The slow crystal growth observed as a result of the interaction between the silver surface and the citrate ion makes this reduction process unique compared to other chemical and radiolytic synthetic methods. The antimicrobial effects of silver (Ag) ion or salts are well known, but the effects of citrate coated Ag nanoparticles (CAgNPs) are scant. Herein, we have isolated biofilm causative bacteria and fungi from drinking water PVC pipe lines. Stable CAgNPs were prepared and the formation of CAgNPs was confirmed by UV-visible spectroscopic analysis and recorded the localized surface plasmon resonance of CAgNPs at 430 nm. Fourier transform infrared spectroscopic analysis revealed C=O and O-H bending vibrations due to organic capping of silver responsible for the reduction and stabilization of the CAgNPs. X-ray diffraction micrograph indicated the face centered cubic structure of the formed CAgNPs, and morphological studies including size (average size 50 nm) were carried out using transmission electron microscopy. The hydrodynamic diameter (60.7 nm) and zeta potential (-27.6 mV) were measured using the dynamic light scattering technique. The antimicrobial activity of CAgNPs was evaluated (in vitro) against the isolated fungi, Gram-negative and Gram-positive bacteria using disc diffusion method and results revealed that CAgNPs with 170ppm concentration are having significant antimicrobial effects against an array of microbes tested.

Correction: Antimicrobial effects of silver deposited on nanolayered manganese oxide

Correction for ‘Antimicrobial effects of silver deposited on nanolayered manganese oxide’ by Mohammad Mahdi Najafpour et al., RSC Adv., 2014, 4, 64688–64691.

Silver in medicine: A brief history BC 335 to present

Silver is a naturally occurring element. Similar to other metals, the ionized form of silver (Ag+1) has known antimicrobial properties. A number of wound dressings incorporating silver ion or silver compounds have recently been developed and marketed. In addition, the antimicrobial effects of silver are currently being promoted in consumer products such as clothing and household appliances.The present use of silver in medical and consumer products has prompted concerns for potential toxicity and ecological effects, including induction of microbial resistance to antibiotics. These concerns ignore the fact that silver has been used for medicinal purposes for several thousand years. A historical review of the uses of silver in medicine is presented.

Antimicrobial effects of silver deposited on nanolayered manganese oxide

The antimicrobial effects of silver deposited on nanolayered manganese oxide forEscherichia coliandStaphylococcus aureuswere considered.

Silver Nanoparticles and Their Antimicrobial Activity on a Few Bacteria

The antimicrobial effects of silver (Ag) ion or salts are well known, but the effects of silver nanoparticles on microorganisms have not been revealed clearly. Here, the antimicrobial properties of silver nanoparticles have been investigated using Bacillus subtilis and methicillin-resistant Staphylococcus aureus. Linoleic acid-protected fine and uniform silver nanoparticles have been prepared through the chemical reduction of silver ions by ethanol. X-ray diffraction study confirms the formation of silver nanoparticles. Transmission electron microscopic image shows a good size distribution of the particles in the range of 4–15 nm. Further, the antimicrobial activity of silver nanoparticles shows that these nanoparticles can be used as effective growth inhibitors.

Silver nanoparticles as a safe preservative for use in cosmetics

Concern is continuously raised regarding the safety of preservatives, which are crucial in most cosmetic preparations. The antimicrobial effects of silver (Ag) are well recognized; however, Ag has some limitations as a preservative, such as its interference with salts. In this study, we investigated the effects of recently synthesized Ag nanoparticles on microorganisms, the permeability of Ag nanoparticles in human skin, and the cytotoxicity of Ag nanoparticles in human keratinocytes under ultraviolet B irradiation. Ag nanoparticles were found to be very stable, and they did not exhibit sedimentation for over 1 year. Ag nanoparticles showed sufficient preservation efficacy against mixed bacteria and mixed fungi, and did not penetrate normal human skin. At concentrations of 0.002–0.02 parts per million, Ag nanoparticles had no effect on HaCaT keratinocytes and did not enhance ultraviolet B-induced cell death. These results suggest that Ag nanoparticles may have potential for use as a preservative in cosmetics. From the Clinical Editor In this study, the effects of recently synthesized Ag nanoparticles were investigated on microorganisms, along with the skin permeability and the cytotoxicity in human keratinocytes under UVB-irradiation. Ag nanoparticles were found to be very stable, showed sufficient preservation efficacy against mixed bacteria and mixed fungi, and did not penetrate normal human skin. Ag nanoparticles appear to be suitable for use as a preservative in cosmetics.

Thermal preparation and stabilization of crystalline silver particles in SiO2-based coating solutions

Ag/SiO2 coating solutions for antimicrobial functionalisation can be prepared by a thermal reaction (reflux or solvothermal conditions) of mixtures of tetraethoxysilane, alkylamine compounds and AgNO3. These coating solutions are especially useful for antimicrobial refinement of temperature sensitive materials like textiles or wood. Moreover coating application onto substrates such as glass or metal, as well as preparation of micrometer sized bulk particles by using a spray-drying process is also feasible. The efficiencies of AgNO3 reduction in the presence of different amine compounds like triethanolamine, triethylamine or diethanolamine are compared. SiO2 nanoparticles are formed by basic hydrolysis of tetraethoxysilane and stabilize the crystalline silver particles in the solution. The antimicrobial effect of silver containing coatings on textile fabrics is investigated.

Silver as a disinfectant.

The antimicrobial effects of silver (Ag) have been recognized for thousands of years. In ancient times, it was used in water containers (Grier 1983) and to prevent putrefaction of liquids and foods. In ancient times in Mexico, water and milk were kept in silver containers (Davis and Etris 1997). Silver was also mentioned in the Roman pharmacopoeia of 69 b.c. (Davis and Etris 1997).

Chemically imaging living cells by scanning electrochemical microscopy

Scanning electrochemical microscopy (SECM) is useful in probing and characterizing interfaces at high resolution. In this paper, the general principles of this technique are described and several applications of SECM to biological systems, particularly to living cells, is discussed, along with several example systems. Thiodione was detected and monitored electrochemically during the treatment of hepatocytes with cytotoxic menadione. The antimicrobial effects of silver(I) was followed by SECM through bacterial respiration. Living HeLa cells were shown to accumulate ferrocencemethanol (FcMeOH) and generated positive feedback for FcMeOH oxidation that can be further used to monitor the cell viability. Finally, individual giant liposomes, as cell models, with encapsulated redox compounds were successfully probed by SECM. In general SECM has the advantage of very high spatial resolution and versatility, especially for the detection of electroactive substances.