scholarly journals Plasmon Resonance of Silver Nanoparticles as a Method of Increasing Their Antibacterial Action

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 80 ◽  
Author(s):  
Alexander Vasil’kov ◽  
Ruslan Dovnar ◽  
Siarhei Smotryn ◽  
Nikolai Iaskevich ◽  
Alexander Naumkin
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Plasmon Resonance ◽  
Photoelectron Spectroscopy ◽  
Antibacterial Properties ◽  
Petri Dish ◽  
Aureus Strain ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray

In this article, a series of silver-containing dressings are prepared by metal-vapor synthesis (MVS), and their antibacterial properties are investigated. The antibacterial activity of the dressings containing silver nanoparticles (AgNPs) against some Gram-positive, and Gram-negative microorganisms (Staphylococcus aureus, Staphylococcus haemolyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Moraxella spp.) has been determined. Based on the plasmon resonance frequency of these nanoparticles, the frequency of laser irradiation of the dressing was chosen. The gauze bandage examined showed pronounced antibacterial properties, especially to Staphylococcus aureus strain. When 470 nm laser radiation, with a power of 5 mW, was applied for 5 min, 4 h after inoculating the Petri dish, and placing a bandage containing silver nanoparticles on it, the antibacterial effect of the latter significantly increased—both against Gram-positive and Gram-negative microorganisms. The structure and chemical composition of the silver-containing nanocomposite were studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS). The synthesized AgNPs demonstrate narrow and monomodal particle size distribution with an average size of 1.75 nm. Atoms of metal in Ag/bandage system are mainly in Ag0 state, and the oxidized atoms are in the form of Ag-Ag-O groups.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

2021 ◽  
Vol 36 (2) ◽  
pp. 93-110
Author(s):  
Princy Philip ◽  
Tomlal Jose ◽  
Sarath KS ◽  
Sunny Kuriakose
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Antibacterial Properties ◽  
Analytical Techniques ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Poly Methyl Methacrylate ◽  
Antimicrobial Studies ◽  
Eye Problems

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

scholarly journals Studies on the antibacterial properties of some basic derivatives of cholane and norcholane

1947 ◽  
Vol 134 (877) ◽  
pp. 538-543 ◽  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Tension ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Lactobacillus Helveticus ◽  
Bacteriostatic Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Derivatives Of

A series of basic derivatives of cholane and norcholane has been examined for bacteriostatic activity against the Gram-positive Staphylococcus aureus and Lactobacillus helveticus and the Gram-negative Bacillus lactis aerogenes . The basic derivatives, in general, were more highly bacteriostatic against the Gram-positive organisms than against the Gram-negative. Of the compounds studied, the highest antibacterial activity was shown by 3:7:12-trihydroxy-23-guanido-norcholane hydrochloride. No relationship was apparent between the lowering of the surface tension of the medium induced by the compounds and their bacteriostatic activity.

scholarly journals Antibacterial Properties of Some Cyclic Organobismuth(III) Compounds

2005 ◽  
Vol 49 (7) ◽  
pp. 2729-2734 ◽  
Author(s):  
Toshiaki Kotani ◽  
Daisuke Nagai ◽  
Kensuke Asahi ◽  
Hitomi Suzuki ◽  
Fumiaki Yamao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Properties ◽  
Cell Number ◽  
Viable Cell Number ◽  
Electron Microscopic ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Ring Compounds ◽  
Medical Disorders

ABSTRACT Bismuth compounds are known for their low levels of toxicity in mammals, and various types of bismuth salts have been used to treat medical disorders. As part of our program to probe this aspect of bismuth chemistry, cyclic organobismuth compounds 1 to 8 bearing a nitrogen or sulfur atom as an additional ring member have been synthesized, and their antimicrobial activities against five standard strains of gram-negative and gram-positive bacteria were assessed. The eight-membered-ring compounds, compounds 1 to 3, exhibited MICs of less than 0.5 μg/ml against Staphylococcus aureus and were more active than the six-membered ones, compounds 5 to 8 (MICs, 4.0 to 16 μg/ml). The gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis) were more susceptible to both types of ring compounds than the gram-negative ones (Escherichia coli and Pseudomonas aeruginosa). Treatment with polymyxin B nonapeptide increased the susceptibility of E. coli to cyclic organobismuth compounds, indicating the low permeability of the outer membrane of gram-negative bacteria to the compounds. Compound 1 also had activity against methicillin-resistant S. aureus, which had an MIC for 90% of the hospital stock strains of 1.25 μg/ml. The killing curves for S. aureus treated with compound 1 or 3 revealed a static effect at a low dose (2× the MIC). However, when S. aureus was treated with 10× the MIC of compound 1 or 3, there was an approximately 3-log reduction in the viable cell number after 48 h of treatment. Electron microscopic inspection demonstrated a considerable increase in the size of S. aureus and the proportion of cells undergoing cell division after treatment with compound 1 at 0.5× the MIC.

scholarly journals Green synthesis of silver nanoparticles using aqueous extract of Citrus sinensis peels and evaluation of their antibacterial efficacy

2021 ◽  
Vol 10 (1) ◽  
pp. 851-859
Author(s):  
Lebogang Mogole ◽  
Wesley Omwoyo ◽  
Elvera Viljoen ◽  
Makwena Moloto
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Citrus Sinensis ◽  
Antimicrobial Activities ◽  
Antibacterial Efficacy ◽  
Gram Positive ◽  
Gram Negative ◽  
Average Size ◽  
Passivating Agent

Abstract The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae. Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity.

scholarly journals Antibacterial Properties of Propolis

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2047 ◽  
Author(s):  
Izabela Przybyłek ◽  
Tomasz M. Karpiński
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Complex Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The World

Researchers are continuing to discover all the properties of propolis due to its complex composition and associated broad spectrum of activities. This review aims to characterize the latest scientific reports in the field of antibacterial activity of this substance. The results of studies on the influence of propolis on more than 600 bacterial strains were analyzed. The greater activity of propolis against Gram-positive bacteria than Gram-negative was confirmed. Moreover, the antimicrobial activity of propolis from different regions of the world was compared. As a result, high activity of propolis from the Middle East was found in relation to both, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Simultaneously, the lowest activity was demonstrated for propolis samples from Germany, Ireland and Korea.

scholarly journals Bacterial Mediated Rapid and Facile Synthesis of Silver Nanoparticles and Their Antimicrobial Efficacy against Pathogenic Microorganisms

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2615
Author(s):  
Md. Amdadul Huq ◽  
Shahina Akter
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Field Emission ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Gram Positive ◽  
Tem Analysis ◽  
Gram Negative ◽  
X Ray

In the present study, silver nanoparticles (AgNPs), biosynthesized using culture supernatant of bacterial strain Paenarthrobacter nicotinovorans MAHUQ-43, were characterized and their antimicrobial activity was investigated against both Gram-positive Bacillus cereus and Gram-negative bacteria Pseudomonas aeruginosa. Bacterial-mediated synthesized AgNPs were characterized by UV-Visible (UV-Vis) spectrophotometer, field emission-transmission electron microscopy (FE-TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) analysis. The UV-Vis spectral analysis showed the absorption maxima at 466 nm which assured the synthesis of AgNPs. The FE-TEM analysis revealed the spherical shape of nanoparticles with the size range from 13 to 27 nm. The EDX and XRD analysis ensured the crystalline nature of biosynthesized AgNPs. The FTIR analysis revealed the involvement of different biomolecules for the synthesis of AgNPs as reducing and capping agents. The bacterial-mediated synthesized AgNPs inhibited the growth of pathogenic strains B. cereus and P. aeruginosa and developed a clear zone of inhibition (ZOI). The MIC and MBC for both pathogens were 12.5 µg/mL and 25 µg/mL, respectively. Moreover, field emission scanning electron microscopy analysis revealed that the synthesized AgNPs can destroy the outer membrane and alter the cell morphology of treated pathogens, leading to the death of cells. This study concludes the eco-friendly, facile and rapid synthesis of AgNPs using P. nicotinovorans MAHUQ-43 and synthesized AgNPs showed excellent antimicrobial activity against both Gram-positive and Gram-negative pathogens.

scholarly journals Phyllanthus reticulatus mediated synthesis and characterization of silver nanoparticles and its antibacterial activity against gram positive and gram negative pathogens

2019 ◽  
Vol 10 (4) ◽  
pp. 3099-3106 ◽  
Author(s):  
Gomathi M ◽  
Prakasam A ◽  
Rajkumar P.V ◽  
Rajeshkumar S ◽  
Chandrasekaran R ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Leaf Extract ◽  
Antibacterial Properties ◽  
Spherical Shape ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Sem Image ◽  
Structural Surface

In this study, silver nanoparticles were successfully synthesized by using Phyllanthus reticulatus leaf extract at different concentration (5, 10, 15 mL). The prepared samples were analyzed their optical, structural, surface morphological properties, and along with these properties, the antibacterial properties were analyzed. The UV-vis absorption spectra show SPR band around 450 nm, shift to lower wavelength due to increasing extract concentration. This shift can be ascribing to a decrease in particle size. The crystallinity nature of the prepared samples is observed by the XRD profile; the calculated particles size by Scherrer’s formula displays a decrease in size with respect to leaf extract volume. From the SEM image, it can be seen that irregular and large size particles prepared at 5-10 mL and the smooth spherical shape and tiny particles were observed in the sample prepared at 15 mL. The small and spherical shape nanoparticles show good antibacterial activity against gram positive and negative bacterial pathogens. The activity of large and irregular shape particles may be due to the release of Ag+ ions and generation of ROS. Because of cell wall difference in bacteria, the better activity is observed against gram negative bacteria.

scholarly journals Silver nanoparticles: an ecological method of synthesis, properties and use against antibiotic resistant microflora

2021 ◽  
Vol 18 (3) ◽  
pp. 351-361
Author(s):  
R. I. Dovnar ◽  
A. Yu. Vasil’kov ◽  
T. M. Sakalova ◽  
A. V. Naumkin ◽  
A. V. Budnikov ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Bacterial Resistance ◽  
Antibacterial Effect ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Average Diameter ◽  
Dilution Method ◽  
Antimicrobial Drugs ◽  
Gram Negative

A quantitative assessment of the antibacterial effect of silver nanoparticles on polyantibiotic-resistant grampositive and gram-negative microorganisms was carried out. Silver nanoparticles were synthesized by the environmentally friendly metal-steam synthesis method. The size and electronic state of nanoparticles were investigated by transmission electron and X-ray photoelectron spectroscopy. The antibacterial properties of nanomaterials were assessed on two clinical pathogenic strains of gram-positive and four strains of gram-negative microorganisms. The typing and assessment of bacterial resistance to antibiotics were carried out on a microbiological analyzer. The antibacterial effect of nanoparticles was quantitatively assessed using the dilution method and the determination of the minimum inhibitory and minimum bactericidal concentrations.It was found that the studied silver nanoparticles have sizes in the range from 5 to 24 nm with an average diameter of 10.8 nm. It was shown that all clinical strains of microorganisms used in the study are characterized by multiple antibacterial resistance; the percentage of their antibiotic resistance ranges from 12.5 to 93.3 %. It was found that for the studied microorganism, the values of the minimum inhibitory concentration (MIC) are in the range from 7.81 to 31.25 μg/ml, and the minimum bactericidal concentration (MBC) is in the range from 31.25 to 62.50 μg/ml. The obtained MIC and MBC data can be used to create promising antimicrobial drugs and medical next generation devices.

scholarly journals SINTESIS KOMPOSIT KITOSAN/MgO/Ag DAN ANALISIS EFEKTIVITASNYA SEBAGAI ANTIBAKTERI

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shintya Maryani ◽  
Henry F Aritonang ◽  
Vanda S Kamu
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Coprecipitation Method ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
Ag Particles ◽  
Scanning Electron

Penelitian tentang sintesis komposit kitosan/MgO/Ag dengan variasi massa prekursor AgNO3 0,05 g, 0,1 g, 0,15 g dan 0,2 g disintesis dengan metode kopresipitasi. Komposit yang dihasilkan dikarakterisasi menggunakan X-Ray Diffractometry (XRD) dan Scanning Electron Microscope (SEM). Selanjutnya, keefektifan komposit ini sebagai antibakteri diuji yaitu Staphylococcus aureus (Gram positif) dan Escherichia coli (Gram negatif). Hasil penelitian menunjukkan bahwa puncak karakteristik partikel MgO dan Ag tidak muncul pada difraktogram XRD, tetapi secara visual dan morfologis SEM mendukung pembentukan dua partikel dan berdasarkan literatur dari hasil peneliti lain. Selain itu, komposit ini efektif dalam menghambat pertumbuhan kedua bakteri.       ABSTRACT Research on the synthesis of chitosan/MgO/Ag composites with variations in the mass of AgNO3 precursors 0.05 g, 0.1 g, 0.15 g and 0.2 g were synthesized by the coprecipitation method. The resulting composites were characterized using X-Ray Diffractometry (XRD) and Scanning Electron Microscope (SEM). Furthermore, the effectiveness of this composite as an antibacterial was tested, namely Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative). The results showed that the characteristic peaks of MgO and Ag particles did not appear on the XRD diffractogram, but visually and morphologically SEM supported the formation of two particles and based on the literature from the results of other researchers. In addition, this composite is effective in inhibiting the growth of both bacteria.

scholarly journals CuO NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND THEIR BACTERICIDAL EFFICACY

2017 ◽  
Vol 9 (6) ◽  
pp. 71 ◽  
Author(s):  
Manyasree D ◽  
Kiran Mayi Peddi ◽  
Ravikumar R
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Copper Oxide ◽  
Cuo Nanoparticles ◽  
Proteus Vulgaris ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
Ft Ir

Objective: In the present study copper oxide (CuO) nanoparticles were synthesized and characterized. The antibacterial activity of CuO nanoparticles was carried out against Escherichia coli, Proteus vulgaris, Staphylococcus aureus and Streptococcus mutans.Methods: The synthesis was carried out by coprecipitation method using copper sulfate and sodium hydroxide as precursors. The synthesized copper oxide nanoparticles were characterized by using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), UV-vis spectroscopy and scanning electron microscope (SEM) with Energy Dispersive X-ray Analysis (EDX) techniques. Besides, this study determines the antibacterial activity and minimum inhibitory concentration (MIC) of CuO nanoparticles against gram-positive (Staphylococcus aureus and Streptococcus mutans) and gram-negative (E. coli and Proteus vulgaris) bacteria.Results: The average crystallite size of CuO nanoparticles was found to be 19 nm by X-ray diffraction. FT-IR spectrum exhibited vibrational modes at 432 cm-1, 511 cm-1 and 611 cm-1were assigned for Cu-O stretching vibration. According to UV-Vis spectrum, two bands were observed at 402 nm and 422 nm. ED’s spectrum shows only elemental copper (Cu) and oxide (O) and no other elemental impurity was observed. The antimicrobial assay revealed that Proteus vulgaris showed a maximum zone of inhibition (37 mm) at 50 mg/ml concentration of CuO nanoparticles.Conclusion: In conclusion, copper oxide is a good antibacterial agent against both gram positive and gram-negative organisms.

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