scholarly journals Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 852
Author(s):  
Tárcio S. Santos ◽  
Tarcisio M. Silva ◽  
Juliana C. Cardoso ◽  
Ricardo L. C. de Albuquerque-Júnior ◽  
Aleksandra Zielinska ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filamentous Fungi ◽  
Entomopathogenic Fungi ◽  
Antimicrobial Agents ◽  
Insect Pests ◽  
Insect Control ◽  
Biological Synthesis ◽  
Biological Methods ◽  
Potential Use

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

scholarly journals Synthesis, Characterization and In Vitro Antibacterial Evaluation of Pyrenacantha grandiflora Conjugated Silver Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1568
Author(s):  
Arinao Murei ◽  
Karen Pillay ◽  
Patrick Govender ◽  
Ntevheleni Thovhogi ◽  
Wilson M. Gitari ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Biological Synthesis ◽  
Klebsiella Pneumonia ◽  
Drug Resistant ◽  
Biological Methods ◽  
Mic Value

In the present study, silver nanoparticles (AgNPs) were synthesized using both the chemical and biological methods and conjugated with Pyrenacantha grandiflora extracts. These were then characterized and evaluated for antimicrobial activities against multi-drug resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumonia, and Escherichia coli. Nanoparticles were analyzed with UV-visible spectrophotometer, transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDX). Silver nanoparticles, P. grandiflora extracts, and the conjugates were also analyzed with Fourier transform infrared spectroscopy (FTIR). As a result, quasi-sphere-shaped AgNPs with sizes ranging from 5 to 33 nm and spherically shaped AgNPs with sizes ranging from 3 to 25 nm were formed from chemical and biological synthesis, respectively. A well diffusion assay showed that the activity of silver nanoparticles was most improved with acetone extract against all tested bacteria with diameters in the range of 19–24 mm. The lowest MIC value of 0.0063 mg/mL against MRSA was observed when biologically synthesized AgNPs were conjugated with acetone and water extracts. Chemically synthesized silver nanoparticles showed the lowest MIC value of 0.0063 mg/mL against E. coli when conjugated with acetone and methanol extracts. This study indicates that silver nanoparticles conjugated with P. gandiflora tubers extracts exhibit strong antibacterial activities against multi-drug resistant bacterial pathogens. Therefore, biosynthesized conjugates could be utilized as antimicrobial agents for effective disease management due to the synergistic antibacterial activity that was observed.

scholarly journals Comparative in vitro activities of trovafloxacin (CP-99,219) against 221 aerobic and 217 anaerobic bacteria isolated from patients with intra-abdominal infections.

1997 ◽  
Vol 41 (10) ◽  
pp. 2312-2316 ◽  
Author(s):  
D M Citron ◽  
M D Appleman
Keyword(s):  
Antimicrobial Agents ◽  
Single Agent ◽  
Anaerobic Bacteria ◽  
Pseudomonas Sp ◽  
Agar Dilution ◽  
Abdominal Infections ◽  
Potential Use ◽  
Polymicrobial Infections

Four hundred thirty-eight bacteria cultured from specimens of patients with serious intra-abdominal infections were tested by agar dilution against trovafloxacin and other quinolones and antimicrobial agents. Trovafloxacin inhibited 435 strains (99.3%) at < or =2 microg/ml. All the quinolones had similar activities against Enterobacteriaceae and Pseudomonas sp., but trovafloxacin showed superior activities against streptococci, enterococci, and anaerobic organisms. Because of its excellent in vitro activities against diverse bacteria, trovafloxacin has potential use as a single agent for polymicrobial infections.

In Vitro Antifungal Activity of Silver Nanoparticles Against Ocular Pathogenic Filamentous Fungi

2013 ◽  
Vol 29 (2) ◽  
pp. 270-274 ◽  
Author(s):  
Yan Xu ◽  
Chuanwen Gao ◽  
Xiaohua Li ◽  
Yi He ◽  
Lutan Zhou ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Filamentous Fungi ◽  
In Vitro Antifungal Activity

In Vitro and In Vivo Antitumor Activity of Silver Nanoparticles on B16 Melanoma

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050163
Author(s):  
Hongkun Gao ◽  
Ping Fan ◽  
Qizhen Xu ◽  
Yiting Li ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antitumor Activity ◽  
Antimicrobial Agents ◽  
Malignant Tumors ◽  
Annexin V ◽  
In Vitro Study ◽  
B16 Melanoma ◽  
Potential Strategy

Melanoma, one of the most malignant tumors, is difficult to treat due to its high drug resistance. Silver nanoparticles (AgNPs) are widely used as antimicrobial agents in biomedical fields. In this study, the spherical AgNPs with average sizes of 5[Formula: see text]nm were prepared using a dopamine reduction method. The in vitro study shows that AgNPs with the concentrations of 0.5[Formula: see text][Formula: see text]g/mL and 1[Formula: see text][Formula: see text]g/mL exhibit good biocompatibility to 3T3L1 fibroblast cells. AgNPs with the same concentrations significantly inhibited the growth of B16 melanoma cells. In culture with B16 cells, AgNPs induced intracellular oxidative stress by generating the reactive oxygen species and reducing the superoxide dismutase, which further reduces the mitochondrial membrane potential. Moreover, the damage in mitochondria could activate mitochondrion-mediated cell apoptosis. The B16 cells apoptosis was analyzed by FITC-Annexin V/propidium iodide double staining assay, which confirms that AgNPs caused the abundance of apoptotic cells in different stages. Thus, AgNPs displayed the antitumor activity in vitro. Then, the therapeutic efficacy in vivo was evaluated in mice-bearing B16 melanoma tumors. The obtained results show the antitumor ability of AgNPs and provide a potential strategy for cancer treatment.

scholarly journals Silver Nanoparticles: Synthesis and Application for Nanomedicine

2019 ◽  
Vol 20 (4) ◽  
pp. 865 ◽  
Author(s):  
Sang Lee ◽  
Bong-Hyun Jun
Keyword(s):  
Silver Nanoparticles ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Biological Synthesis ◽  
Optoelectronic Property ◽  
Substantial Impact ◽  
Biomedical Device ◽  
Imaging Probes ◽  
Shape Controlled ◽  
Bimetallic Structures

Over the past few decades, metal nanoparticles less than 100 nm in diameter have made a substantial impact across diverse biomedical applications, such as diagnostic and medical devices, for personalized healthcare practice. In particular, silver nanoparticles (AgNPs) have great potential in a broad range of applications as antimicrobial agents, biomedical device coatings, drug-delivery carriers, imaging probes, and diagnostic and optoelectronic platforms, since they have discrete physical and optical properties and biochemical functionality tailored by diverse size- and shape-controlled AgNPs. In this review, we aimed to present major routes of synthesis of AgNPs, including physical, chemical, and biological synthesis processes, along with discrete physiochemical characteristics of AgNPs. We also discuss the underlying intricate molecular mechanisms behind their plasmonic properties on mono/bimetallic structures, potential cellular/microbial cytotoxicity, and optoelectronic property. Lastly, we conclude this review with a summary of current applications of AgNPs in nanoscience and nanomedicine and discuss their future perspectives in these areas.

An efficient protocol for the synthesis of new camphor pyrimidine and camphor thiazole derivatives using conventional and microwave irradiation techniques and in vitro evaluation as potential antimicrobial agents

2022 ◽  
Vol 19 ◽  
Author(s):  
Entesar A. Hassan ◽  
Salem E. Zayed ◽  
Al-Hassan S. Mahdy ◽  
Ahmed M. Abo-Bakr
Keyword(s):  
Microwave Irradiation ◽  
Mass Spectra ◽  
Antimicrobial Agents ◽  
Microwave Irradiation Method ◽  
Pyrimidine Derivatives ◽  
Thiazole Derivatives ◽  
Ft Ir ◽  
New Compounds ◽  
Potential Use

Background: A series of new pyrimidines and thiazoles containing camphor moiety were synthesized under both conventional and microwave irradiation techniques. Methods: The condensation of camphor either with aminoguanidine or thiosemicarbazide gives the camphor hydrazine carboximidiamide 2 and the camphor thiosemicarbazone 3, respectively. Refluxing of 3 with chloroacetonitrile afforded the camphor thiazol-4-imine 4. Compounds 2 and 4 were used as precursors for the synthesis of target products. Results: The reaction of 2 with different species such as arylidene malononitrile, acetylacetone, and ethyl acetoacetate gave the corresponding camphor pyrimidine derivatives 5a,b-7 while refluxing of compound 4 with different reagents e.g. aldehydes, isatin, ninhydrin, acetic anhydride, benzene sulphonyl chloride, and p-nitro-benzoyl chloride afforded the camphor thiazole derivatives 8a-d-13, respectively. Conclusion: A comparison between the conventional way and the eco-friendly microwave irradiation method occurred in the synthesis of the same compounds, which the latter was more efficient. The elemental analysis, FT-IR, 1H NMR, 13C NMR, and Mass spectra confirm the structures of the obtained new compounds. The potential use of some selected derivatives as antimicrobial agents was investigated and gave promising results

scholarly journals Synergy of Silver Nanoparticles and Aztreonam against Pseudomonas aeruginosa PAO1 Biofilms

2014 ◽  
Vol 58 (10) ◽  
pp. 5818-5830 ◽  
Author(s):  
Marc B. Habash ◽  
Amber J. Park ◽  
Emily C. Vis ◽  
Robert J. Harris ◽  
Cezar M. Khursigara
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Cell Envelope ◽  
Antimicrobial Properties ◽  
Planktonic Cell ◽  
Chronic Infections ◽  
Content Type

ABSTRACTPathogenic bacterial biofilms, such as those found in the lungs of patients with cystic fibrosis (CF), exhibit increased antimicrobial resistance, due in part to the inherent architecture of the biofilm community. The protection provided by the biofilm limits antimicrobial dispersion and penetration and reduces the efficacy of antibiotics that normally inhibit planktonic cell growth. Thus, alternative antimicrobial strategies are required to combat persistent infections. The antimicrobial properties of silver have been known for decades, but silver and silver-containing compounds have recently seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the efficacy of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the monobactam antibiotic aztreonam, to inhibitPseudomonas aeruginosaPAO1 biofilms. Among the different sizes of AgNPs examined, 10-nm nanoparticles were most effective in inhibiting the recovery ofP. aeruginosabiofilm cultures and showed synergy of inhibition when combined with sub-MIC levels of aztreonam. Visualization of biofilms treated with combinations of 10-nm AgNPs and aztreonam indicated that the synergistic bactericidal effects are likely caused by better penetration of the small AgNPs into the biofilm matrix, which enhances the deleterious effects of aztreonam against the cell envelope ofP. aeruginosawithin the biofilms. These data suggest that small AgNPs synergistically enhance the antimicrobial effects of aztreonam againstP. aeruginosain vitro, and they reveal a potential role for combinations of small AgNPs and antibiotics in treating patients with chronic infections.

In Vitro Susceptibility of Silver Nanoparticles on Thai Isolated Fungus Pyricularia oryzae from Oryza sativa L. Leaves

2017 ◽  
Vol 866 ◽  
pp. 148-151 ◽  
Author(s):  
Duongruitai Nicomrat ◽  
Wannaphan Janlapha ◽  
Nuanchan Singkran
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Fungal Growth ◽  
Hyphal Growth ◽  
Pyricularia Oryzae ◽  
Surface Areas ◽  
Previously Treated ◽  
Rice Leaves ◽  
Bacteria And Fungi

Silver nanoparticles (AgNPS) have been known for their effectiveness as antimicrobial agents due to their extremely large relative surface areas increases their contact with bacteria and fungi thus improving its bacteriocidal and fungicidal effectiveness. In this experiment, AgNPs were tested for antifungal activity on a rice blast fungus, Pyricuralia oryzae which is anamorph of Magnaporthe oryzae. In Vitro inhibitory property of AgNPs were observed on the fungi isolated from rice leaves and the survival isolates after AgNP treatment. The results showed AgNPs retarded and reduced the fungal growth at low concentration of 25 μg ml-1. The retarded fungi after previously treated with AgNPs gave very slower hyphal growth. The results demonstrated that AgNP can strongly inhibit the fungal growth and colony formation. AgNPs can thus be improved to be promising antifungal agents against Pyricularia oryzae with its suitable formula of AgNP in the fungicidal materials.

scholarly journals Synergistic Antifungal Activity of Green Synthesized Silver Nanoparticles and Epoxiconazole against Setosphaeria turcica

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Weidong Huang ◽  
Minhui Yan ◽  
Haiming Duan ◽  
Yaling Bi ◽  
Xinxin Cheng ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Integrated Control ◽  
Antimicrobial Effect ◽  
Colony Growth ◽  
Setosphaeria Turcica ◽  
Ligustrum Lucidum ◽  
In Vitro Inoculation ◽  
Average Size

It is urgent to develop highly efficient and eco-friendly antimicrobial agents for integrated control of phytopathogens. Silver nanoparticles (AgNPs) were synthesized by Ligustrum lucidum leaf extract. UV-vis spectrum showed that there was a strong absorbance at 438 nm. Transmission electron microscopy (TEM) images displayed that synthesized nanoparticles were near spherical with an average size of 13 nm. The antimicrobial effect of AgNPs was evaluated through methods of paper disk diffusion, colony growth, conidia germination, and in vitro inoculation. The 50% inhibition concentration (IC50) of AgNPs against Setosphaeria turcica was 170.20 μg/mL calculated by SPSS 13.0. In addition, it displayed a significant synergistic antifungal effect when AgNPs were combined with epoxiconazole at the ratios of 8 : 2 and 9 : 1. The results of this study provide a novel fungistat not only for comprehensive control of plant fungi but also for reducing chemical pesticides use and avoiding drug-resistant phytopathogen generation.

Green synthesis of silver nanoparticles from Catunaregam tomentosa extract

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chanyapat Ittibenjapong ◽  
Prit Kanjanahitanon ◽  
Punnita Chaichamni ◽  
Sirirat Panich ◽  
Nuchutha Thamsumet
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Antioxidant Activities ◽  
Biological Synthesis ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Medical Supplies ◽  
Significant Difference ◽  
Size Stability ◽  
Biological Methods

Abstract Silver nanoparticles (AgNPs) have been widely used in many fields (e.g., sensors, medical supplies, food, cosmetics, medicines, etc.) due to their unique properties such as optical property, antibacterial property, and high conductivity. AgNPs are normally synthesized by chemical, physical, or biological methods. Among these methods, biological synthesis or green synthesis of AgNPs has drawn much attention since it is an easy and environmental-friendly method. Herein, AgNPs synthesized using Catunaregam tomentosa extracts were studied. The extracts obtained from different C. tomentosa fruit were found to be blue, green, and brown. It was found from the foam test and IR spectra that all extracts (blue, green, and brown extracts) contained saponins. According to the DPPH assay, the blue and the green extracts had the antioxidant activities of 84.47 ± 12.13 and 47.66 ± 2.86 mg ascorbic acid equivalent/g of C. tomentosa powder, respectively. This showed that the blue and the green extracts could act as reducing agents in AgNPs synthesis. The successfully synthesized AgNPs using C. tomentosa extracts showed the surface plasmon resonance peak at 400 nm corresponding to literatures. The particle sizes and zeta potential values measured by dynamic light scattering also indicated the size stability of the synthesized AgNPs during seven-day period with no significant difference (P > 0.05).

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