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Enhanced antibacterial and anti-biofilm activities of silver nanoparticles against Gram-negative and Gram-positive bacteria.

Gurunathan S, Han JW, Kwon DN, Kim JH - Nanoscale Res Lett (2014)

Bottom Line: The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics.The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively.These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 143-701, South Korea ; GS Institute of Bio and Nanotechnology, Coimbatore, Tamilnadu, India.

ABSTRACT
Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.

No MeSH data available.


Related in: MedlinePlus

Characterization of AgNPs synthesized using A. cobbe leaf extracts. The absorption spectra of AgNPs exhibited a strong, broad peak at 420 nm. This band was attributed to the surface plasmon resonance of the AgNPs. The images show the spectrum of AgNO3(1), leaf extract (2), and mixture of AgNO3 and leaf extract (3) at 6 h exposure. After exposure for 6 h, the color of the colloidal solution of AgNPs turned from green to dark brown, indicating the formation of AgNPs.
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Figure 1: Characterization of AgNPs synthesized using A. cobbe leaf extracts. The absorption spectra of AgNPs exhibited a strong, broad peak at 420 nm. This band was attributed to the surface plasmon resonance of the AgNPs. The images show the spectrum of AgNO3(1), leaf extract (2), and mixture of AgNO3 and leaf extract (3) at 6 h exposure. After exposure for 6 h, the color of the colloidal solution of AgNPs turned from green to dark brown, indicating the formation of AgNPs.

Mentions: The aim of this experiment was to produce smaller sizes of AgNPs using A. cobbe leaf extract, which acts as a reducing as well as stabilizing/capping agent. In order to control the particle size of AgNPs, 5 mM AgNO3 was added to the leaf extract and incubated for 6 h at 60°C at pH 8.0. Synthesis was confirmed by visual observation of the leaf extract and AgNO3. The mixture of leaf extract and AgNO3 showed a color change from green to brown. No color change was observed during incubation of leaf extract without AgNO3 (Figure 1). The appearance of a brown color in AgNO3-treated leaf extract suggested the formation of AgNPs (Gurunathan et al. [4,16]; Sathiya and Akilandeswari [26]).


Enhanced antibacterial and anti-biofilm activities of silver nanoparticles against Gram-negative and Gram-positive bacteria.

Gurunathan S, Han JW, Kwon DN, Kim JH - Nanoscale Res Lett (2014)

Characterization of AgNPs synthesized using A. cobbe leaf extracts. The absorption spectra of AgNPs exhibited a strong, broad peak at 420 nm. This band was attributed to the surface plasmon resonance of the AgNPs. The images show the spectrum of AgNO3(1), leaf extract (2), and mixture of AgNO3 and leaf extract (3) at 6 h exposure. After exposure for 6 h, the color of the colloidal solution of AgNPs turned from green to dark brown, indicating the formation of AgNPs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4127560&req=5

Figure 1: Characterization of AgNPs synthesized using A. cobbe leaf extracts. The absorption spectra of AgNPs exhibited a strong, broad peak at 420 nm. This band was attributed to the surface plasmon resonance of the AgNPs. The images show the spectrum of AgNO3(1), leaf extract (2), and mixture of AgNO3 and leaf extract (3) at 6 h exposure. After exposure for 6 h, the color of the colloidal solution of AgNPs turned from green to dark brown, indicating the formation of AgNPs.
Mentions: The aim of this experiment was to produce smaller sizes of AgNPs using A. cobbe leaf extract, which acts as a reducing as well as stabilizing/capping agent. In order to control the particle size of AgNPs, 5 mM AgNO3 was added to the leaf extract and incubated for 6 h at 60°C at pH 8.0. Synthesis was confirmed by visual observation of the leaf extract and AgNO3. The mixture of leaf extract and AgNO3 showed a color change from green to brown. No color change was observed during incubation of leaf extract without AgNO3 (Figure 1). The appearance of a brown color in AgNO3-treated leaf extract suggested the formation of AgNPs (Gurunathan et al. [4,16]; Sathiya and Akilandeswari [26]).

Bottom Line: The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics.The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively.These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 143-701, South Korea ; GS Institute of Bio and Nanotechnology, Coimbatore, Tamilnadu, India.

ABSTRACT
Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.

No MeSH data available.


Related in: MedlinePlus