Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

scholarly journals Evaluation of Antimicrobial Activity of Cymbopogon citratus Essential Oil Alone and in Combination with Origanum majorana and Caryophyllus aromaticus Essential Oils against Some Foodborne Bacteria

2019 ◽  
Vol 7 (2) ◽  
pp. 60-67
Author(s):  
Razieh Partovi ◽  
Fazele Talebi ◽  
Zahra Boluki ◽  
Aghil Sharifzadeh
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Minimum Inhibitory Concentration ◽  
Essential Oils ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Cymbopogon Citratus ◽  
Foodborne Bacteria ◽  
Origanum Majorana ◽  
Time Kill

Background: Food spoilage and foodborne diseases are two important problems in the food industry. On the other hand, consumers’ tendency to use natural additives is increasing. Hence, plant essential oils (EOs) can be safe alternatives in this regard. Objective: The objectives were to determine the chemical composition and to evaluate the antimicrobial activity of Cymbopogon citratus EO against some foodborne bacteria alone and in combination with Origanum majorana and Caryophyllus aromaticus EOs. Materials and Methods: Chemical composition of C. citratus EO was analyzed by gas chromatography-mass spectrometry. Further, antibacterial activity of the EO against foodborne bacteria was assessed using disk diffusion method. In addition, the minimum inhibitory concentration of the EO was determined by microdilution broth method and then the minimum bactericidal concentration value was determined. Checkerboard synergy testing was also performed to determine the fractional inhibitory concentration index. Finally, time-kill curves were drawn based on the bacterial population (CFU/mL) against time (h). Results: The major compounds of C. citratus EO were isothymol, thymol, trans-caryophyllene, and cymene. The most and the least sensitive foodborne bacteria to C. citratus EO were Staphylococcus aureus and Bacillus subtilis, respectively. The minimum inhibitory concentration (MIC) values of C. citratus EO against all the evaluated bacteria were 0.1% and The minimum bactericidal concentration (MBC) values ranged between 0.1 and >2% (v/v). The combination of C. citratus and O. majorana EOs showed a synergistic activity against Salmonella typhimurium and partial synergism against B. subtilis, Escherichia coli O157:H7, S. aureus, and Listeria monocytogenes. Moreover, the combination of C. citratus and C. aromaticus EOs demonstrated partial synergism against S. aureus and L. monocytogenes, and additive interaction against S. typhimurium; however, the combination was indifferent against E. coli O157:H7 and B. subtilis. Furthermore, C. citratus plus O. majorana EOs and C. citratus plus C. aromaticus EOs showed a bactericidal effect against S. typhimurium after 24 hours in the time-kill assay. Conclusion: In general, the synergism, partial synergism, and additive effects of C. citratus in combination with C. aromaticus and O. majorana EOs strengthen the antimicrobial activity, expand the spectrum of activity, reduce the concentrations required, decrease the side effects, and prevent the alteration of organoleptic properties of food.

Conjugation of Silver Nanoparticles with De Novo Engineered Cationic Antimicrobial Peptides: Proposal for Study (Preprint)

2021 ◽  
Author(s):  
Alvin Hu
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
De Novo ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Cationic Antimicrobial Peptides ◽  
Drug Resistant Bacteria

BACKGROUND Cationic antimicrobial peptides have broad antimicrobial activity and provide a novel way of targeting multi drug resistant bacteria in an era of increasing antimicrobial resistance. Current developments show positive prospects for both antimicrobial peptides and silver nanoparticles individually. OBJECTIVE The primary objective is to propose another method of enhancing antimicrobial activity by conjugating silver nanoparticles with cationic antimicrobial peptides for a subsequent preliminary assessment on studying the minimum inhibitory concentration of multi drug resistant bacteria. The secondary objective would be to evaluate the safety of the conjugated compound to assess viability for in vivo use. METHODS The proposition is planned for approximately 3 overarching stages. Firstly, I propose synthesis of wlbu2c, a modified version of antimicrobial peptide wlbu2 with an added cysteine group, using standard Fmoc procedure. This will subsequently be attempted to stably conjugate with silver nanoparticles ideally through photochemical means. Secondly, the conjugate wlbu2c-AgNP will be tested for antimicrobial activity following Clinical & Laboratory Standards Institute Manual on standard minimum inhibitory concentration testing. If all of the above is completed the experiment can progress to the assessment of cytotoxicity using cell lysis assays. RESULTS I-TASSER simulation revealed that our modified peptide wlbu2c has similar secondary structure to original wlbu2 peptide. No other results have been obtained at this time other than aforementioned theoretical propositions. CONCLUSIONS The addition of silver nanoparticles to already developing de novo engineered antimicrobial peptides provide a second degree of freedom toward the development of potent antimicrobials. Future prospects include emergency last line therapy, treatment for current difficult to eradicate bacterial colonization such as in cystic fibrosis, implantable medical devices, cancer and immunotherapy. This proposal is intended to be provided to the public as I do not anticipate funding at this time.

scholarly journals Antimicrobial potential of Casearia sylvestris against oral bacteria

2016 ◽  
Vol 45 (4) ◽  
pp. 214-218 ◽  
Author(s):  
Amanda Henriques CAVALHEIRO ◽  
Ana Paula Terossi GODOI ◽  
Tatiane Cruz de CARVALHO ◽  
Alma Blasida CATIRSE ◽  
Niege Araçari Jacometti Cardoso FURTADO
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Essential Oil ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Antimicrobial Activities ◽  
Positive Control ◽  
Oral Bacteria ◽  
Volatile Fraction ◽  
Casearia Sylvestris

Abstract Aim The aim of this study was to obtain Casearia sylvestris leave extracts by different extractive methods, including the obtention of essential oil, in order to compare their antimicrobial activities to conventional mouthwash chlorhexidine against oral bacteria. Material and method For this evaluation, extracts from the leaves were obtained by different methods of extraction (infusion, decoction, maceration and percolation) using different solvent systems: water 100%, ethanol 100%, methanol 100%, water: ethanol 3:7; water: ethanol 7:3; water: methanol 7:3 and water: methanol 3:7. The essential oil, which corresponds to a volatile fraction, was obtained by hydrodistillation using Clevenger modified apparatus. The microdilution broth method was used to determine the values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the following microorganisms: Streptococcus mutans ATCC 25175, S. mitis ATCC 49456, S. sanguinis ATCC 10556, S. salivarius ATCC 25975, Lactobacillus casei ATCC 11578 and Enterococcus faecalis ATCC4082. Chlorhexidine gluconate was used as a positive control. Result All extracts evaluated in the used protocol displayed MIC values higher than 400 µg/mL and few showed bactericidal activity. The antimicrobial activity of essential oil was higher than the activity of the extracts, and the best minimum inhibitory concentration and minimum bactericidal concentration values were obtained against L. casei (MIC of 0.023 µg/mL and MBC of 0.046 µg/mL) and S. mutans (MIC of 25 µg/mL and MBC of 50 µg/mL), respectively. Conclusion The essential oil of Casearia sylvestris has significant antimicrobial activity against oral microorganisms.

scholarly journals In Vitro Test: Antimicrobial Activity Potential From Ciplukan Fruit (Physalis minima L.) Extract in Methicillin-resistant Staphylococcus aureus (MRSA)

2020 ◽  
Vol 4 (2) ◽  
pp. 209
Author(s):  
Muhammad Hanun Mahyuddin ◽  
Arifa Mustika ◽  
Gwenny Ichsan Prabowo ◽  
Deby Kusumaningrum
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Test Tube ◽  
In Vitro Test ◽  
Fruit Extract ◽  
Methicillin Resistant

Abstract  In Indonesia, in 2006, the prevalence of infections due to MRSA was 23.5%. Physalis minima L. plants are known to have antimicrobial activity because they contain compounds withaferin A, which can induce programmed cell death. This research was to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Ciplukan (Physalis minima L.) extract in Methicillin-resistant Staphylococcus aureus (MRSA) bacteria. Dilution test with Mueller-Hinton broth medium used for measuring the minimum inhibitory concentration (MIC). Ciplukan  fruit extract was dissolved in distilled water, and poured into a test tube with a certain concentration (0.9 g/mL (90%); 0.3 g/mL (45%); 0.15 g/mL (22.5%); 0.075 g/mL (11.25%) and 0.0375 g/mL (5.625%). After being incubated for 24 hours, the bacteria in the test tube were plated on nutrient agar plates to determine the MBC. The MIC cannot be determined, because the medium in the dilution test tube is disturbed by the color of the extract so that turbidity cannot be observed. From the observations of the minimum bactericidal concentration, MBC of the Ciplukan (Physalis minima  L.) fruit extract against MRSA was in the P1 tube or equivalent to 0.9 g / ml (90%).Keywords             : Physalis minima L., Antimicrobial, Ciplukan, Methicillin-resistant Staphylococcus aureus, Withaferin ACorrespondence   : [email protected]

scholarly journals Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Neonatal Meningitis ◽  
E Coli ◽  
Drug Candidates ◽  
Metabolic Genes ◽  
Genetic Mechanisms ◽  
Cell Stress Response

Abstract Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.

scholarly journals THE EFFECT OF PROPOLIS EXTRACT AND PROPOLIS CANDIES ON THE GROWTH OF AGGREGATIBACTER ACTINOMYCETEMCOMITANS ATCC 43718

2017 ◽  
Vol 10 (17) ◽  
pp. 26
Author(s):  
Khodijah Khodijah ◽  
Ratna Farida ◽  
Nurtami Soedarsono
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Spectrophotometric Analysis ◽  
Propolis Extract ◽  
Post Exposure ◽  
Colony Forming Units

Objective: This experiment aimed to analyze the effect of propolis extract and propolis containing candies on the growth of Aggregatibacter actinomycetemcomitans using spectrophotometric analysis and colony-forming units (CFU) counts.Methods: After A. actinomycetemcomitans were exposed to propolis extract and candies, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined with spectrophotometry and post-exposure colony counting.Results: The MIC of propolis extract against A. actinomycetemcomitans was determined to be 10%, and the MBC was 20%. A decrease in the total CFU count of A. actinomycetemcomitans was observed after propolis extract and candy exposure.Conclusions: Propolis extract and propolis candies were effective in inhibiting the growth of A. actinomycetemcomitans ATCC 43718 in vitro.

scholarly journals Antimicrobial Activity of Bauhinia Purpurea (L) by Minimum Inhibitory Concentration (MIC) Method

2017 ◽  
Vol 12 (01) ◽  
pp. 69-71
Author(s):  
Shamala T ◽  
A.M. Krupanidhi ◽  
Shanmukhappa S ◽  
B.E. Basavarajappa ◽  
Jayamma kulkarni
Keyword(s):  
Antimicrobial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Bauhinia Purpurea

scholarly journals Study and evaluation of antimicrobial activity and antioxidant capacity of dry extract and fractions of leaves of Raphanus sativus var. oleiferus Metzg.

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Ana Flávia da Silva ◽  
Marisa de Oliveira Lopes ◽  
Cláudio Daniel Cerdeira ◽  
Ingridy Simone Ribeiro ◽  
Isael Aparecido Rosa ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Minimum Inhibitory Concentration ◽  
Ethyl Acetate ◽  
Raphanus Sativus ◽  
Inhibitory Concentration ◽  
Ethyl Acetate Fraction ◽  
Antimicrobial Activities ◽  
Dry Extract ◽  
Antioxidant And Antimicrobial Activities

The radish (Raphanus sativus L.) is a vegetable of the Brassicaceae family cultivated worldwide and has several medicinal properties. Its biological activities are related to various secondary metabolites present in the species, especially phenolics. Thus, the objectives of this study were the chemical analysis and evaluation of the antioxidant and antimicrobial activities of the dry extract and fractions of the fodder turnip leaves (R. sativus var. oleiferus Metzg.). Samples were analyzed by mass spectrometry and the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the reducing power method. Antimicrobial activity was determined by the agar diffusion and microdilution methods. The total phenols were concentrated in the butanol fraction (121.27 mg GAE/g) and the flavonoids were concentrated in the ethyl acetate fraction (98.02 mg EQ/g). The ethyl acetate fraction showed the best antioxidants results, with 83.45% of free radical scavenging and 11.34% of ferric ions reduction. The analysis of antimicrobial activity showed that the dry extract had the highest average zone of inhibition against Bacillus subtilis (18.67 mm). Smaller values of the minimum inhibitory concentration for Micrococcus luteus were, and the ethyl acetate fraction showed a lower minimum inhibitory concentration (0.1 mg/ml) for that microorganism. There was a strong correlation between the antioxidant activity and the content of phenols and flavonoids. The results showed the potential antioxidant and antimicrobial activities of this extract with the ethyl acetate fraction being most promising for further studies.

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