scholarly journals Extracellular Synthesis and Characterization of Silver Nanoparticles—Antibacterial Activity against Multidrug-Resistant Bacterial Strains

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 360 ◽  
Author(s):  
Gajanan Ghodake ◽  
Min Kim ◽  
Jung-Suk Sung ◽  
Surendra Shinde ◽  
Jiwook Yang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Morphological Changes ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Electron Microscopic ◽  
Visible Absorption ◽  
Membrane Function ◽  
Extracellular Synthesis

Herein, we report the use of a cell-free extract for the extracellular synthesis of silver nanoparticles (AgNPs) and their potential to address the growing threat of multidrug-resistant (MDR) pathogenic bacteria. The reproducibility of AgNP synthesis was good and AgNP formation kinetics were monitored as a function of various reaction factors via ultraviolet-visible absorption spectroscopy. This green method was dependent on the alkaline pH of the reaction mixture. With the addition of dilute sodium hydroxide, well-dispersed AgNPs could be produced in large quantities via the classical nucleation and growth route. The new biosynthetic route enabled the production of AgNPs within a narrow size range of 4 to 17 nm. The AgNPs were characterized using various techniques and their antibacterial activity against MDR pathogenic bacteria was evaluated. Field-emission scanning electron microscopic imaging revealed prominent morphological changes in Staphylococcus aureus cells due to mechanical damage, which led to cell death. Escherichia coli cells showed signs of contraction and intracellular fluid discharge as a consequence of disrupted cell membrane function. This new biologically-assisted extracellular strategy is potentially useful for the decontamination of surfaces and is expected to contribute to the development of new products containing AgNPs.

scholarly journals Synthesis of silver nanoparticles using Lactobacillus bulgaricus and assessment of their antibacterial potential

2022 ◽  
Vol 82 ◽  
Author(s):  
Q. A. Naseer ◽  
X. Xue ◽  
X. Wang ◽  
S. Dang ◽  
S. U. Din ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Lactobacillus Bulgaricus ◽  
Health Concern ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Visible Absorption

Abstract Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in “De Man, Rogasa, and Sharp” broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell- free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.

scholarly journals Biomimetic Synthesis of Silver Nanoparticles from Aqueous Extract of Saraca indica and its Profound Antibacterial Activity

2020 ◽  
Vol 11 (1) ◽  
pp. 8110-8120
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Aqueous Extract ◽  
Silver Nanoparticle ◽  
Pathogenic Bacteria ◽  
Drug Formulation ◽  
Biomimetic Synthesis ◽  
Visible Absorption ◽  
The Stability ◽  
Average Size

The present findings were focused on green synthesis of silver nanoparticles through an aqueous extract of Saraca indica. The stability of the nanoparticle was achieved through the optimization of physico-chemical parameters. The sharp UV-visible absorption maximum at 400 was observed for biological synthesized silver nanoparticles. The spectroscopic analysis was thus used to assess the formation of silver nanoparticles. The AFM analysis did analyze the morphology of the nanocomposite, which was further confirmed through TEM micrograph. The electron micrograph image discloses that silver nanoparticles were polydispersed and dominantly as spherical with size ranges from 40nm to 100nm. The average size distribution was 49nm. The chemical reductions of Ag+ ions were further confirmed through FTIR. The biogenic silver nanoparticle and their drug formulation showed profound antibacterial activity against pathogenic bacteria. The flavonoids rich binding of silver nanoparticle showed great medicinal potential and can be used for the treatment of several harmful infectious diseases. Hence, plant-based metal nanoparticles meet the demand for less toxic formulation during drug development and its delivery.

scholarly journals Antibacterial activity of selected snake venoms on pathogenic bacterial strains

2019 ◽  
Vol 27 (3) ◽  
pp. 305-317 ◽  
Author(s):  
Francisc Andrei Boda ◽  
Anca Mare ◽  
Zoltán István Szabó ◽  
Lavinia Berta ◽  
Augustin Curticapean ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Snake Venoms ◽  
Starting Point ◽  
Sds Page ◽  
Potential Use ◽  
Selection Of

Abstract Snake venoms are aqueous solutions containing peptides and proteins with various biochemical, physiological, and pathophysiological effects. Several snake venom components are used as lead molecules in the development of new active substances for the treatment of cardiovascular diseases, clotting disorders, cancer or pain. Antibacterial activity has also been attributed to snake venoms and proteins isolated from snake venoms. This study provides information regarding the antibacterial activity of venoms obtained from various snake species from the Elapidae and Viperidae families. Minimum inhibitory and bactericidal concentrations of snake venoms were determined for three Gram-positive (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213, and Methicillin-resistant Staphylococcus aureus ATCC 43300) and three Gram-negative (Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, and Pseudomonas aeruginosa ATCC 27853) pathogenic bacteria. The observed effects were correlated with the protein content of each venom, determined using SDS-PAGE analysis and comparison with data available in the literature. Our findings represent a starting point for the selection of snake venoms containing components with potential use as lead molecules in the development of new antibacterial agents, targeting multidrug resistant bacterial strains.

scholarly journals Bacterial nanobiotic potential

2020 ◽  
Vol 9 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Shabana Wagi ◽  
Ambreen Ahmed
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Bacterial Strains ◽  
Extracellular Biosynthesis ◽  
Green Production ◽  
Antibacterial And Antifungal ◽  
Antibacterial Potential

AbstractAntibiotics are the chemicals responsible for killing pathogenic bacteria but inappropriate and extensive use of antibiotics is hazardous causing adverse impact on human health. Excessive use of antibiotics has led to the development of multiple-drug resistant bacteria posing health hazards to mankind. The study of nanoparticles has revolutionized the problem solving concerns regarding fields of agriculture, chemistry and medicine. Nanoparticles are smaller than atomic nuclei offering more surface area and greater reactivity. Bacterial silver nanoparticles (AgNPs) were studied for their antibacterial potential. AgNPs from Bacillus subtilus show the highest antibacterial activity. Nanoparticles exhibiting antibacterial activity can be helpful to reduce the toxic impact of synthetic antibiotics. Present work deals with the green production of silver nanoparticles by exploiting indigenous bacteria. These AgNPs were characterized through Fourier transform infrared spectroscopic (FTIR) analysis, transmission electron microscopy (TEM) and UV spectroscopic analysis and were also evaluated for their antibacterial and antifungal potential. The data suggested the extracellular biosynthesis method to be very effective for the biosynthesis of AgNPs in some bacterial strains. Keeping in view the antibacterial potential of studied AgNPs, the present work suggests green production of nanoparticles which can be effectively utilized as environment friendly antibacterial and antifungal agents.

scholarly journals SILVER NANOPARTICLES FROM TRIANTHEMA PORTULACASTRUM: GREEN SYNTHESIS, CHARACTERIZATION, ANTIBACTERIAL AND ANTICANCER PROPERTIES

2017 ◽  
Vol 10 (3) ◽  
pp. 308
Author(s):  
Gowri Shankar Krishnan ◽  
Namrata Pradhan ◽  
Masilamani K ◽  
Albin T Fleming
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Pathogenic Bacteria ◽  
Synthesis Method ◽  
Silver Ions ◽  
Bacterial Strains ◽  
X Ray ◽  
Nih 3T3 ◽  
Dose Dependent

ABSTRACTObjective: In this study, silver nanoparticles (SNPs) were synthesized using an aqueous extract of Trainthema portulacastrum and silver ions (Ag+)which have been proven against certain pathogenic bacterial strains and hepatocellular carcinoma (HepG2) cell line.Methods: The bio fabricated nanoparticles were confirmed by surface plasmon resonance which were characterized by biophysical measuresutilizing the ultraviolet-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray, and transmission electron microscope(TEM), Fourier transform infrared spectroscopy, particle size analyzer, and X-ray diffraction. Antibacterial efficacy against Enterobacter aerogens,Proteus mirabilis, Escherichia coli, Staphylococcus epidermis, and Bacillus subtilis. The effect of SNPs tested against HepG2 and NIH/3T3 cell lineexhibits a dose-dependent toxicity.Results and Conclusion: The SEM and TEM images confirmed the presence of spherical and hexagonal shape (0.3-4 μm) of nanocrystalline particleswith the size range of 11.5-29.2 nm. The average particles size of SNPs is 190.3±17.0 nm. Antibacterial activity was carried out by agar well diffusionmethod against different pathogenic bacteria of which B. subtilis showed a significant zone of inhibition 8.66 mm and 12.0 mm for aqueous plantextract and synthesized SNPs. The effect of SNPs tested against HepG2 and NIH/3T3 cell line exhibits a dose-dependent toxicity. In case of HepG2, thecell viability was decreased to 50% (IC50) at the concentration of 173.8±0.84 μg/mL. From the results, it can be concluded that the SNPs fabricatedusing green synthesis method will be a promising candidate in the biomedical field, due to its high bioactive properties.Keywords: Silver nanoparticles, Trainthema portulacastrum, Antibacterial activity, Cytotoxic activity.

scholarly journals Biogenic Silver Nanoparticles Synthesized by Lysinibacillus xylanilyticus MAHUQ-40 to Control Antibiotic-Resistant Human Pathogens Vibrio parahaemolyticus and Salmonella Typhimurium

2020 ◽  
Vol 8 ◽  
Author(s):  
Md. Amdadul Huq
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Salmonella Typhimurium ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Morphological Changes ◽  
Membrane Integrity ◽  
Human Pathogens ◽  
Tem Analysis ◽  
Antibiotic Resistant

The present study highlights a simple and eco-friendly method for the biosynthesis of silver nanoparticles (AgNPs) using Lysinibacillus xylanilyticus strain MAHUQ-40. Also, the synthesized AgNPs were used to investigate their antibacterial activity and mechanisms against antibiotic-resistant pathogens. Biosynthesis of AgNPs was confirmed by ultraviolet–visible spectroscopy, and then, they were characterized by field emission-transmission electron microscopy (FE-TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and fourier transform-infrared (FTIR). The toxicity of AgNPs against two pathogenic bacteria was evaluated. The UV–vis spectral scanning showed the peak for synthesized AgNPs at 438 nm. Under FE-TEM, the synthesized AgNPs were spherical with diameter ranges from 8 to 30 nm. The XRD analysis revealed the crystallinity of synthesized AgNPs. FTIR data showed various biomolecules including proteins and polysaccharides that may be involved in the synthesis and stabilization of AgNPs. The resultant AgNPs showed significant antibacterial activity against tested pathogens. The MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations) of the AgNPs synthesized by strain MAHUQ-40 were 3.12 and 12.5 μg/ml, respectively, against Vibrio parahaemolyticus and 6.25 and 25 μg/ml, respectively, against Salmonella Typhimurium. FE-TEM analysis showed that the biogenic AgNPs generated structural and morphological changes and damaged the membrane integrity of pathogenic bacteria. Our findings showed the potentiality of L. xylanilyticus MAHUQ-40 to synthesis AgNPs that acted as potent antibacterial material against pathogenic bacterial strains.

Biochemical Composition, Antibacterial and Anti-Biofilm Activities of Indian Medicinal Plants

2020 ◽  
Vol 18 ◽  
Author(s):  
Mulugeta Mulat ◽  
Fazlurrahman Khan ◽  
Archana Pandita
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Pathogenic Bacteria ◽  
Chemical Constituents ◽  
Multidrug Resistant ◽  
Chloroform Extract ◽  
Acetone Extract ◽  
Biologically Active ◽  
Ocimum Sanctum ◽  
Agar Disc

Background: Medicinal plants have been used for treatments of various health ailments and the practices as a remedial back to thousands of years. Currently, plant-derived compounds used as alternative ways of treatment for multidrug-resistant pathogens. Objective: In the present study, various parts of six medical plants such as Solanum nigrum, Azadirachta indica, Vitex negundo, Mentha arvensis, Gloriosa superba, and Ocimum sanctum were extracted for obtaining biological active constituents. Methods: Soxhlet method of extraction was used for obtaining crude extracts. Agar disc diffusion and 96-well plate spectroscopic reading were used to detect the extract’s antibacterial and antibiofilm properties. Results: The obtained extracts were tested for antimicrobial and antibiofilm properties at 25 mg/mL concentrations. Maximum antibacterial activity was observed in O. sanctum chloroform extract (TUCE) against Staphylococcus aureus (24.33±1.52 mm), S. nigrum acetone extract (MAAC) against Salmonella Typhimurium (12.6 ± 1.5 mm) and Pseudomonas aeruginosa (15.0 ±2.0 mm). Only TUCE exhibited antibacterial activity at least a minimum inhibitory concentration of 0.781 mg/mL. Better antibiofilm activities were also exhibited by petroleum extracts of G. superba (KAPE) and S. nigrum (MAPE) against Escherichia coli, S. Typhimurium, P. aeruginosa and S. aureus. Moreover, S. nigrum acetone extract (MAAC) and O. sanctum chloroform extract (TUCE) were showed anti-swarming activity with a reduction of motility 56.3% against P. aeruginosa and 37.2% against S. aureus. MAAC also inhibits Las A activity (63.3% reduction) in P. aeruginosa. Conclusion: Extracts of TUCE, MAAC, MAPE, and KAPE were exhibited antibacterial and antibiofilm properties against the Gram-positive and Gram-negative pathogenic bacteria. GCMS identified chemical constituents are responsible for being biologically active.

scholarly journals Alkaloid-Rich Crude Extracts, Fractions and Piperamide Alkaloids of Piper guineense Possess Promising Antibacterial Effects

Antibiotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 98 ◽  
Author(s):  
Eunice Mgbeahuruike ◽  
Pia Fyhrquist ◽  
Heikki Vuorela ◽  
Riitta Julkunen-Tiitto ◽  
Yvonne Holm
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Hot Water ◽  
Bacterial Strains ◽  
Inhibitory Effects ◽  
Piper Guineense ◽  
E Coli ◽  
Growth Inhibitory ◽  
Derivatives Of

Piper guineense is a food and medicinal plant commonly used to treat infectious diseases in West-African traditional medicine. In a bid to identify new antibacterial compounds due to bacterial resistance to antibiotics, twelve extracts of P. guineense fruits and leaves, obtained by sequential extraction, as well as the piperine and piperlongumine commercial compounds were evaluated for antibacterial activity against human pathogenic bacteria. HPLC-DAD and UHPLC/Q-TOF MS analysis were conducted to characterize and identify the compounds present in the extracts with promising antibacterial activity. The extracts, with the exception of the hot water decoctions and macerations, contained piperamide alkaloids as their main constituents. Piperine, dihydropiperine, piperylin, dihydropiperylin or piperlonguminine, dihydropiperlonguminine, wisanine, dihydrowisanine and derivatives of piperine and piperidine were identified in a hexane extract of the leaf. In addition, some new piperamide alkaloids were identified, such as a piperine and a piperidine alkaloid derivative and two unknown piperamide alkaloids. To the best of our knowledge, there are no piperamides reported in the literature with similar UVλ absorption maxima and masses. A piperamide alkaloid-rich hexane leaf extract recorded the lowest MIC of 19 µg/mL against Sarcina sp. and gave promising growth inhibitory effects against S. aureus and E. aerogenes as well, inhibiting the growth of both bacteria with a MIC of 78 µg/mL. Moreover, this is the first report of the antibacterial activity of P. guineense extracts against Sarcina sp. and E. aerogenes. Marked growth inhibition was also obtained for chloroform extracts of the leaves and fruits against P. aeruginosa with a MIC value of 78 µg/mL. Piperine and piperlongumine were active against E. aerogenes, S. aureus, E. coli, S. enterica, P. mirabilis and B. cereus with MIC values ranging from 39–1250 µg/mL. Notably, the water extracts, which were almost devoid of piperamide alkaloids, were not active against the bacterial strains. Our results demonstrate that P. guineense contains antibacterial alkaloids that could be relevant for the discovery of new natural antibiotics.

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