Chitosan Silver Nano Composites (CAgNCs) as Antibacterial Agent Against Fish Pathogenic Edwardsiella tarda (original) (raw)
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Indian Journal of Microbiology, 2017
Development of nanostructured films using natural polymers and metals has become a considerable interest in various biomedical applications. Objective of the present study was to develop silver nano particles (AgNPs) embedded chitosan films with antimicrobial properties. Based on the Ag content, two types of chitosan silver nano films, named as CAgNfs-12 (12 mM) and CAgNfs-52 (52 mM) were prepared and characterized. Field emission scanning electron microscope (FE-SEM) images of two CAgNfs showed the circular AgNPs, which were uniformly embedded and distributed in the matrix of chitosan films. Antimicrobial experiment results clearly indicated that CAgNfs can inhibit the growth of fish pathogenic bacteria Vibrio (Allivibrio) salmonicida, V. tapetis, Edwardsiella tarda and fungi Fusarium oxysporum. Moreover, CAgNfs significantly reduced the experimentally exposed V. salmonicida levels in artificial seawater, suggesting that these CAgNfs could be used to develop antimicrobial filters/m...
Chitosan Silver Nano Composites (Cagncs) as Potential Antibacterial Agent to Control Vibrio tapetis
Journal of Veterinary Science & Technology, 2014
Nanocomposites exhibit high performance on antimicrobial activities and have the potential to be developed alternative antibiotics. In this study, antibacterial effects of chitosan silver nano composites (CAgNCs) were investigated using pathogenic Vibrio tapetis as a bacterial model. Agar disc diffusion and turbidimetric assay results showed that CAgNCs could inhibit the growth of V. tapetis in concentration depended manner. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CAgNCs against V. tapetis were 50 μg/mL and 100 μg/mL, respectively. The field emission scanning electron microscopy (FE-SEM) images analysis of V. tapetis showed severe structural damage to cells after treating CAgNCs at 75 μg/mL compared to untreated bacteria. Moreover, CAgNCs induce the intracellular ROS level, leakage of nucleic materials (RNA and DNA), decrease the cell viability and protein level in V. tapetis cells. Herein, we demonstrate that CAgNCs as effective antibacterial agent with capability to disrupt cell membrane, destabilize the membrane permeability, induce the oxidative stress and inhibit the expression of protein or synthesis of macromolecules. Overall results from this study suggest that mode of action of CAgNCs may be associated with excessive generation of ROS, loss in membrane integrity and inhibiting protein synthesis that cause the bacterial cell death.
Advances in Materials Science and Engineering, 2013
The aim of this study is to investigate the antibacterial properties and characterization of chitosan-silver nanoparticle composite materials. Chitosan-silver nanoparticle composite material was synthesized by adding AgNO3and NaOH solutions to chitosan solution at 95°C. Different concentrations (0,02 M, 0,04 M, and 0,06 M) of AgNO3were used for synthesis. Chitosan-silver nanoparticle composite materials were characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet (UV) spectrophotometer, and Fourier transform infrared (FTIR) spectrometer techniques.Escherichia coli,Acinetobacter baumannii,Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa, andStreptococcus pneumoniaewere used to test the bactericidal efficiency of synthesized chitosan-Ag nanoparticle composite materials. The biological activity was determined by the minimum bacterial concentration (MBC) of the materials. Antibacterial effect of chitosan-silver nanoparticle materia...
Factors Affecting the Antibacterial Activity of Chitosan-Silver Nanocomposite
IET Nanobiotechnology, 2017
This study provides the optimum preparation parameters of chitosan-silver nanoparticles composite (CSNC) with promising antibacterial activity against the most common bacterial infections found on burn wounds. CSNC was synthesised by simple green chemical reduction method with different preparation factors. Chitosan was used to reduce silver nitrate and stabilise silver nanoparticles in the medium. For this reason, spectroscopic and microscopic techniques as, ultraviolet-visible Fourier transform infrared spectroscopy and transmission electron microscopy were used in the study of the molecular and morphological properties of the resultant composites. Furthermore, the composite was assessed in terms of Ag-ions release by AAS and its efficacy as antibacterial material. As a result, CSNC showed stronger antibacterial effect than its individual components (chitosan and silver nitrate solutions) towards Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. CSNC prepared in this study showed highest inhibition percentage of bacterial growth up to 96% at concentration of 220 μg/ml.
2018
A simple and eco-friendly approach has been successfully developed for the preparation of chitosan nanocomposites films loaded with silver nanoparticles using kumquat extract as a biological reducing agent. The chitosan/silver nanocomposites (CTS/Ag NCPs) films were prepared from chitosan/silver nanocomposites solution and dried for 14 h at 70C in a vacuum oven with the pressure of 0.03 Mpa. The morphology and characterization of CTS/Ag NCPs films have been also determined by FTIR, XRD, and SEM. The UV-vis spectroscopy and TEM image indicated that synthesized chitosan/silver nanocomposites have spherical shape with their uniform dispersion and their average particle size of about 20-30 nm. The prepared CTS/Ag NCPs films showed their great antibacterial activity on Staphylococcus aureus (S. Aureus) and Escherichia coli (E. coli). Therefore, this eco-friendly method that would be used for the preparation of chitosan/Ag nanocomposites films could be competitive and alternative to the e...
Synthesis of Chitosan-silver nanocomposites and their antibacterial activity
International Journal of Scientific and Engineering Research
The present study explores the in situ fabrication of chitosan-silver nanocomposites in view of their increasing applications as antimicrobial packaging, wound dressing and antibacterial materials. Chitosan/Silver nanocomposites were prepared by embedding of silver nanoparticles in chitosan polymer. Synthesis of nanocomposites was confirmed by Fourier Transform Infrared (FTIR) spectroscopy, X-Ray Diffraction (XRD) analysis and Differential Scanning Calorimetry (DSC) etc. In addition, the formed nanocomposites have an average particle size of ~10-15 nm as observed by Transmission Electron Microscopy (TEM). Their antibacterial activity was assessed by zone of inhibition method against Staphylococcus aureus MTCC 1809, Pseudomonas aeruginosa MTCC 424 and Salmonella entrica MTCC 1253 in vitro.
Nanosilver-marine fungal chitosan as antibiotic synergizers against sepsis fish bacteria
Iranian Journal of Microbiology, 2015
Background and Objectives: Mortality is highly variable within population of cultured fish due to virulent bacteria causing fish septicemia. The use of nano-silver marine fungal chitosan as antibiotic synergisers could be an alternative in the treatment of sepsis fish pathogens. Materials and Methods: Different bulk chitosan solutions were prepared from the mycelia of four marine fungi (Aspergillus terreus, Aspergillus flavipes, Tricoderma hamatum and Fennellia flavipes) and used as capping agents for silver nanoparticles. In vitro, the antibacterial activity of these preparations was determined against nine fish-sepsis causing bacteria, alone and in combination with nine antibiotics of choice used in aquaculture. Prepared fungal chitosans (CsF) were characterized by yield of chistosan obtained, degree of deacetylation and viscosity. Results and Conclusion: The maximum yield of chitosan (28%) was obtained from Aspergillus terreus. A. terreus chitosan (CsF), silver nanoparticles (AgN...
The antibacterial properties of a novel chitosan–Ag-nanoparticle composite
International journal of …, 2008
Escherichia coli expressing recombinant green fluorescent protein was used to test the bactericidal efficacy of a newly synthesized chitosan-Ag-nanoparticle composite. The composite was found to have significantly higher antimicrobial activity than its components at their respective concentrations. The one-pot synthesis method led to the formation of small Ag nanoparticles attached to the polymer which can be dispersed in media of pH ≤ 6.3. The presence of a small percentage (2.15%, w/w) of metal nanoparticles in the composite was enough to significantly enhance inactivation of E. coli as compared with unaltered chitosan. Fluorescence spectroscopy indicated that bacterial growth stopped immediately after exposure of E. coli to the composite, with release of cellular green fluorescent protein into the medium at a faster rate than with chitosan. Fluorescence confocal laser scanning and scanning electron microscopy showed attachment of the bacteria to the composite and their subsequent fragmentation. Native protein gel electrophoresis experiments indicated no effect of the composite on bacterial proteins.
Due to their antibacterial activity and biocompatibility, chitosan and chitosan derivatives have ability of participating in biological applications. The prepared Cs g-PAN/Ag nanocomposites are reported as antibacterial agents that exhibit efficient antibacterial activity in vitro. The prepared chitosan-g- PAN/Ag nanocomposite was provided by FTIR and gravimetric methods. UV spectra and TEM images show silver nanoparticles with average 15 20 nm dispersed homogeneously in (CS-g-PAN/Ag) nanocomposite. The antimicrobial activity examined against gram negative bacterium (E. coli) and gram positive bacterium (Staphylococcus aureus) in addition to yeast (Candida albicans) and fungi (Aspergillusniger) is evaluated in vitro. The MIC for E. coli for in vivo application was also examined. In vivo antibacterial activity against E. coli has been evaluated by using an intestine-infected rat model. Experimental results indicated that the number of bacteria surviving in the small intestine is lower than in the untreated group. These nanocomposite open up a new avenue for design and synthesis of next-generation antibacterial agents as alternatives to antibiotics.
European Polymer Journal
n the present work chitosan-silver (CS/Ag) nanocomposites, either in the form of nanoparticles (AgNP) or as ionic dendritic structures (Ag+), are synthesized by a simple and environmentally friendly in situ chemical reduction process. The antibacterial activity of the resulting nanocomposites in the form of films is studied against two bacteria, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The relationship between electrical, structural and antibacterial properties of CS/AgNP and CS/Ag+ nanocomposites are studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction, and UV-Vis, impedance, infrared and X-ray photoelectron spectroscopies. The results demonstrate that in contrast to CS/Ag+ ion films, the CS/AgNP composites films (average particle size less than 10 nm) showed a significantly higher antibacterial potency. The collective action of AgNP and Ag+ ions facilitate the enhancement and synergetic antibacteria...