scholarly journals Characterization and Antimicrobial Activity of Silver Nanoparticles Synthesized with the Peel Extract of Mango

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5878
Author(s):  
Yage Xing ◽  
Xingmei Liao ◽  
Xiaocui Liu ◽  
Wenxiu Li ◽  
Ruihan Huang ◽  
...  

The green synthesis of silver nanoparticles (AgNPs) from biological waste, as well as their excellent antibacterial properties, is currently attracting significant research attention. This study synthesized AgNPs from different mango peel extract concentrations while investigating their characteristics and antibacterial properties. The results showed that the AgNPs were irregular with rod-like, spherical shapes and were detected in a range of 25 nm to 75 nm. The AgNPs displayed antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), showing a more significant impact when synthesized with 0.20 g/mL of mango peel extract. Therefore, the antibacterial effect of different diluted AgNP concentrations on the growth kinetic curves of E. coli and S. aureus after synthesis with 0.20 g/mL mango peel extract was analyzed. The results indicated that the AgNP antibacterial activity was higher against S. aureus than against E. coli, while the AgNP IC50 in these two strains was approximately 1.557 mg/mL and 2.335 mg/L, respectively. This research provides new insights regarding the use of postharvest mango byproducts and the potential for developing additional AgNP composite antibacterial materials for fruit and vegetable preservation.

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1529
Author(s):  
Yu-Hsuan Chen ◽  
Wei-Hsun Wang ◽  
Sheng-Hui Lin ◽  
Yuan-Ting Yang-Wang ◽  
Sung-Pin Tseng ◽  
...  

Acinetobacter baumannii (A. baumannii) is a common and challenging pathogen of nosocomial infections, due to its ability to survive on inanimate objects, desiccation tolerance, and resistance to disinfectants. In this study, we investigated an antibacterial strategy to combat A. baumannii via the combination of antibiotics and silver protein. This strategy used a functional platform consisting of silver nanoparticles (AgNPs) resurrected from silver-based calcium thiophosphate (SSCP) through casein and arginine. Then, the silver protein was combined with tigecycline, the first drug in glycylcycline antibiotic, to synergistically inhibit the viability of A. baumannii. The synergistic antibacterial activity was confirmed by the 96-well checkerboard method to determine their minimum inhibitory concentrations (MIC) and calculated for the combination index (CI). The MIC of the combination of silver protein and tigecycline (0.31 mg/mL, 0.16 µg/mL) was significantly lower than that of the individual MIC, and the CI was 0.59, which indicates a synergistic effect. Consequently, we integrated the detailed synergistic antibacterial properties when silver protein was combined with tigecycline. The result could make for a promising approach for the treatment of A. baumannii.


Author(s):  
В.Т. Долгих ◽  
Л.Г. Пьянова ◽  
Т.И. Долгих ◽  
В.А. Лихолобов ◽  
О.В. Корпачева ◽  
...  

Цель исследования - изучение антибактериальной активности гранулированных углеродных сорбентов по отношению к патогенной микрофлоре в условиях различной продолжительности контакта с сорбентом. Методика. Исследовали антибактериальные свойства гранулированного сорбента ВНИИТУ-1, обработанного гидромеханически, окисленного и стабилизированного до нормативных значений рН и модифицированного поли-N-винилпирролидоном (ПВП) ВНИИТУ-1 по отношению к патогенным микроорганизмам: Staphylococcus aureus, Pseudomonas aeroginosa, Klebsiella pneumonia, Escherichia coli, Streptococcus agalactiae, а также к их смесям. Все микроорганизмы представляли собой клинические штаммы, выделенные из ран пациентов. Предварительно тест-микроорганизмы были исследованы на чувствительность к современным антибиотикам. Опытным путем подбирали такие разведения и количество засеваемого материала, чтобы выросшие на чашке Петри колонии можно было сосчитать. Бактерии сорбировали из физиологического раствора с концентрацией микробных клеток 3 х 10 колониеобразующих единиц в 1 мл исследуемой пробы (КОЕ/мл). В пробирку типа Эппендорф вносили сорбент в количестве 0,5 мл, добавляли 1 мл микробной взвеси, встряхивали для удаления пузырьков воздуха и выдерживали в термостате в течение 1, 3, 6 и 24 ч. По истечении заданного времени контакта сорбента с патогенной микрофлорой отбирали надосадочную жидкость в объеме 100 мкл, засевали на стерильные агаровые пластины чашек Петри с питательной средой ГМФ-агар. Засеянные чашки Петри помещали в СО-инкубатор 15АС (Япония) вверх дном и инкубировали при температуре 37 ± 1°С в течение 24 ± 2 ч. При подсчете колоний, выросших на чашке Петри, учитывали только те чашки, на которых выросло более 300 изолированных колоний. Результаты. Гранулированный сорбент ВНИИТУ-1 обладает антибактериальным действием в отношении как грамположительных, так и грамотрицательных бактерий, а также их смеси. Сроки проявления антибактериального эффекта сорбента зависят от вида микроорганизмов и времени их контакта с образцом. Присутствие в составе сорбента модификатора ПВП усиливает его антибактериальные свойства. Полимермодифицированный образец обладает пролонгированным антибактериальным эффектом в отношении широкого спектра микроорганизмов (E. coli, St. aureus, P. aeruginosae и St. aureus) и смеси их культур. Заключение. Показана возможность повышения антибактериальных свойств гранулированных углеродных сорбентов по отношению к патогенной микрофлоре путем их модификации поли-N-винилпирролидоном. Дальнейшая разработка и применение углеродных сорбентов как средств сорбционной терапии является перспективным подходом к местному лечению гнойных ран. The purpose: Study the antibacterial activity of granulated carbon sorbents in relation to the pathogenic microflora under the conditions of different period of contact with sorbent. Methods. It has been investigated the antibacterial properties of VNIITU-1 granulated sorbent, which was hydromechanically treated, oxidized and stabilized up to pH standard parameters and VNIITU-1 modified poly-N-vinylpyrrolidone (PVP) against the pathogenic micro-organisms, including Staphylococcus aureus, Pseudomonas aeroginosa, Klebsiella pneumonia, Escherichia coli, Streptococcus agalactiae, and their mixes. All bacteria were clinical strains derived from the wounds of patients. Dilutions and amount of inoculated material were experimentally selected for further calculation of the grown colonies on the Petri dish. Bacteria were sorbed from the saline solution with bacteria concentration of 3 х 10 of the colony forming units in 1 ml of test sample (CFU/ ml). Eppendorf tube was added the sorbent 0.5 ml and bacterial suspension 1 ml; then the tube was shaken to remove the air bubbles and incubated for 1, 3, 6 and 24 hr. Upon the expiry of the target time for sorbent with pathogenic flora contact the supernatant fluid was collected in 100 ul and inoculated on the sterile agar plates of the Petri dishes with GMF agar nutrient medium. Inoculated Petri dishes were placed upside down in СО incubator 15AC (Japan) and incubated at 37 ± 1°C for 24 ± 2 hours. When counting the colonies growing on the Petri dish, they took into consideration only the dishes where more than 300 isolated colonies were grown. If more than 300 colonies were grown, «> 3x102 CFU/ml» was recorded in the protocol. Results. Granulated sorbent VNIITU-1 has an antibacterial effect against both gram-positive and gram-negative bacteria, and their mixes. Time period for manifestations of the sorbent antibacterial effect depends on the type of microorganisms and time of contact. PVP presence in sorbent composition enhances the antibacterial effect of the sorbent. Resin-modified sample has a prolonged antibacterial effect against a broad spectrum of microorganisms (E. coli, St. aureus, P. aeruginosae and St. aureus) and mixtures of their cultures. Conclusion. It has been determined the possibility for increasing of antibacterial properties of granulated carbon sorbents against the pathogenic microflora by their modification with poly-N-vinylpyrrolidone. Further development and application of carbon sorbents as the means for sorption therapy is a perspective approach for the local treatment of purulent wounds.


Planta Medica ◽  
2020 ◽  
Vol 86 (15) ◽  
pp. 1089-1096
Author(s):  
Karmen Kapp ◽  
Anne Orav ◽  
Mati Roasto ◽  
Ain Raal ◽  
Tõnu Püssa ◽  
...  

AbstractMint flavorings are widely used in confections, beverages, and dairy products. For the first time, mint flavoring composition of mint candies and food supplements (n = 45), originating from 16 countries, as well as their antibacterial properties, was analyzed. The flavorings were isolated by Marcussonʼs type micro-apparatus and analyzed by GC-MS. The total content of the mint flavoring hydrodistilled extracts was in the range of 0.01 – 0.9%. The most abundant compounds identified in the extracts were limonene, 1,8-cineole, menthone, menthofuran, isomenthone, menthol and its isomers, menthyl acetate. The antimicrobial activity of 13 reference substances and 10 selected mint flavoring hydrodistilled extracts was tested on Escherichia coli and Staphylococcus aureus by broth dilution method. Linalool acetate and (−)-carvone, as most active against both bacteria, had the lowest MIC90 values. (+)-Menthyl acetate, (−)-menthyl acetate, and limonene showed no antimicrobial activity. Three of the tested extracts had antimicrobial activity against E. coli and 8 extracts against S. aureus. Their summary antimicrobial activity was not always in concordance with the activities of respective reference substances.


2020 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Gabriele Meroni ◽  
Joel F. Soares Filipe ◽  
Piera A. Martino

Silver nanoparticles (AgNPs) are promising alternatives to antibiotics. The aims of this study were to produce AgNPs using two biological methods and determine their antibacterial activity against Pseudomonas aeruginosa and Staphylococcus pseudintermedius. AgNPs were biosynthesized from an infusion of Curcuma longa (turmeric) and the culture supernatant of E. coli. Characterization was achieved by ultraviolet-visible spectroscopy and by Transmission Electron Microscopy (TEM). The antibacterial properties of NPs from C. longa (ClAgNPs) and E. coli (EcAgNPs), alone and in combination with carbenicillin and ampicillin, were investigated through the Kirby-Bauer disk diffusion assay and the minimum inhibitory concentration (MIC). Dimensions of NPs ranged from 11.107 ± 2.705 nm (ClAgNPs) to 27.282 ± 2.68 nm (EcAgNPs). Kirby-Bauer and MIC assays showed great antibacterial abilities for both NPs alone and in combination with antibiotics. EcAgNPs alone showed the most powerful antibacterial activities, resulting in MIC values ranging from 0.438 ± 0.18 µM (P. aeruginosa) to 3.75 ± 3.65 µM (S. pseudintermedius) compared to those of ClAgNPs: 71.8 ± 0 µM (P. aeruginosa) and 143.7 ± 0 µM (S. pseudintermedius). The antibiofilm abilities were strain-dependent, but no statistical differences were found between the two NPs. These results suggest the antibacterial potential of AgNPs for the treatment of infectious diseases.


2021 ◽  
pp. 096739112110374
Author(s):  
Ruge Cao ◽  
Xuqing Zhai ◽  
Xueyang Li ◽  
Xiaoyu Zhao

To prevent microbial contamination in foods and medical tools, we prepared a novel antibacterial material nano-silver loaded poly(styrene-co-acrylic) (nAg-PSA) composites by in situ reductions. The nAg-PSA was characterized by scanning electron microscope, transmission electron microscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis. The antibacterial properties of nAg-PSA against Escherichia coli and Staphylococcus aureus were systematically evaluated, and the underlying mechanism was investigated. Results showed that the silver nanoparticles were successfully loaded onto PSA microspheres, highly dispersed on the surface of nAg-PSA nanoparticles. The nAg-PSA nanoparticles all showed significant antibacterial effects, among which nAg-PSA4 had maximum diameters of inhibition zones against the Gram-negative E. coli (1.18 mm) and the Gram-positive S. aureus (1.29 mm), respectively, which closely related to the size and density of silver nanoparticles covered on the surface.


PHARMACON ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 211
Author(s):  
Excel Pangouw ◽  
Jimmy Posangi ◽  
Widya Astuty Lolo ◽  
Robert Bara

ABSTRACTEndophytic fungi are fungi that live in plant tissues and do not harm the plants. Endophytic fungi can produce compounds that have the potential to be antibacterial. This study aims to examine the antibacterial activity of endophytic fungi isolated from the leaves and stems of the cat's whiskers plant (Orthosiphon aristatus) against Escherichia coli and Staphylococcus aureus bacteria. Cat's whiskers contain essential oils which are used as antibacterial against some pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. The method used is experimentally in the laboratory to test the antibacterial activity of endophytic fungi isolates derived from cat's whiskers (Orthosiphon aristatus) on Escherichia coli and Staphylococcus aureus bacteria using the hole / well method. In the research results obtained four samples of endophytic fungi extract isolated from the leaves and stems of the cat's whiskers plant (Orthosiphon aristatus) . The results of antibacterial research showed that endophytic mushroom extract isolated from cat's whiskers were more effective in inhibiting Escherichia coli bacteria compared to Staphylococcus aureus. In Escherichia coli bacteria the average value of inhibition is 5 mm whereas in Staphylococcus aureus bacteria the average value of inhibition is only 2 mm. So it can be seen that the endophytic fungus from the leaves of cat's whiskers has a better antibacterial effect than the endophytic fungus from the stems of the cat's whiskets. Conclusion, etidophytic fungi isolated from leaves and stems of cat's whiskers (Orthosiphon aristatus) have an antibacterial effect on the growth of E. coli bacteria and are not effective against S. aureus bacteria.Keywords: Cat's whiskers (Orthasiphan aristatus), antibacterial activity, Escherichia coli and Staphylococcus aureus. ABSTRAKJamur endofit ialah jamur yang hidup di dalam jaringan tumbuhan dan tidak membahayakan tumbuhan tersebut. Jamur endofit dapat menghasilkan senyawa yang berpotensi sebagai antibakteri. Penelitian ini bertujuan untuk menguji aktivitas antibakteri jamur endofit yang diisolasi dari daun dan batang tumbuhan kumis kucing (Orthosiphon aristatus) terhadap Bakteri Escherichia coli dan Staphylococcus aureus. Kumis kucing mengandung minyak atsiri yang digunakan sebagai antibakteri terhadap beberapa bakteri patogen seperti Staphylococcus aureus dan Escherichia coli. Metode yang dipakai yakni secara eksperimen di laboratorium untuk menguji adanya aktivitas antibakteri dari isolat jamur endofit  yang diberasal dari tumbuhan kumis kucing (Orthosiphon aristatus)  pada bakteri  Escherichia coli dan Staphylococcus aureus dengan menggunakan metode lubang/sumuran. Pada hasil penelitan didapatkan empat sampel ekstrak jamur endofit yang diisolasi dari daun dan batang  tumbuhan kumis kucing (Orthosiphon aristatus). Hasil penelitian antibakteri menunjukkan bahwa ekstrak jamur endofit yang diisolasi dari tumbuhan kumis kucing lebih efektif menghambat  bakteri Escherichia coli dibandingkan dengan bakteri Staphylococcus aureus. Pada bakteri  Escherichia coli nilai rata-rata daya hambat yaitu 5 mm sedangkan pada bakteri Staphylococcus aureus nilai rata-rata daya hambat yaitu hanya 2 mm. Sehingga dapat diketahui bahwa jamur endofit dari daun kumis kucing memiliki efek antibakteri yang lebih baik dibandingkan dengan jamur endofit dari batang kumis kucing. Kesimpulan, Jamur endofit yang diisolasi dari daun  dan batang kumis kucing (Orthosiphon aristatus) memiliki efek antibakteri terhadap pertumbuhan bakteri E. coli dan tidak efektiv terhadap bakteri S. aureus.Kata Kunci:  Tumbuhan kumis kucing (Orthosiphon aristatus), aktivitas antibakteri, Escherichia coli dan Staphylococcu saureus.


2018 ◽  
Vol 69 (6) ◽  
pp. 1485-1488
Author(s):  
Marioara Nicoleta Filimon ◽  
Roxana Popescu ◽  
Adrian Sinitean ◽  
Paula Maniu ◽  
Gabi Dumitrescu ◽  
...  

The interest in the antimicrobial actions of chitosan is due to its multiple properties and effects. The aim of the study was to assess the potential antibacterial effects of chitosan applied on 7 bacterial strains: Escherichia coli, Streptococcus pyogenes, Pseudomonas aeruginosa, Enterococcus faecalis, Clostridium perfringens, Legionella pneumophila and Staphylococcus aureus. Six different concentrations of chitosan were dissolved in 1% acetic acid, following two working protocols (Kirby-Bauer method and testing for bacterial cell viability). The sensitivity of tested bacterial strains following the effect of exposure to chitosan decreased as follows: E. coli] L. pneumophila] S. aureus] S. pyogenes] C. perfringens] P. aeruginosa] E. faecalis. The inhibition rates for the bacterial strains E. faecalis, S. pyogenes and S. aureus highlighted again the strong antibacterial properties of this product. Conclude that the chitosan presents a different antibacterial effect against several bacterial strains of interest directly with the employed concentrations.


2021 ◽  
pp. 1330-1341
Author(s):  
Mbarga M. J. Arsène ◽  
I. V. Podoprigora ◽  
Anyutoulou K. L. Davares ◽  
Marouf Razan ◽  
M. S. Das ◽  
...  

Background and Aim: The gradual loss of efficacy of conventional antibiotics is a global issue. Plant material extracts and green-synthesized nanoparticles are among the most promising options to address this problem. Therefore, the aim of this study was to assess the antibacterial properties of aqueous and hydroalcoholic extracts of grapefruit peels as well as their inclusion in green-synthesized silver nanoparticles (AgNPs). Materials and Methods: Aqueous and hydroalcoholic extracts (80% v/v) were prepared, and the volume and mass yields were determined. The synthesis of AgNPs was done in an eco-friendly manner using AgNO3 as a precursor. The nanoparticles were characterized by ultraviolet–vis spectrometry and photon cross-correlation spectroscopy. The antibacterial activity of the extracts was tested on three Gram-positive bacteria (Staphylococcus aureus ATCC 6538, clinical Enterococcus faecalis, and S. aureus) and two Gram-negative bacteria (two clinical Escherichia coli) using various concentrations of extracts (100, 50, 25, 12, and 5 mg/mL and 5% dimethyl sulfoxide as negative control). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the microdilution method. Modulation of cefazoline and ampicillin on resistant E. coli and S. aureus strains was added to the mixture design response surface methodology with extreme vertices design, with the diameters of inhibition and the fractional inhibitory concentration index as responses and factors, respectively. The antibiotic, the ethanolic extract, and water varied from 0.1 MIC to 0.9 MIC for the first two and from 0 to 0.8 in proportion for the third. Validating the models was done by calculating the absolute average deviation, bias factor, and accuracy factor. Results: The volume yield of the EE and aqueous extract (AE) was 96.2% and 93.8% (v/v), respectively, whereas their mass yields were 7.84% and 9.41% (m/m), respectively. The synthesized AgNPs were very uniform and homogeneous, and their size was dependent on the concentration of AgNO3. The antibacterial activity of the two extracts was dose-dependent, and the largest inhibition diameter was observed for the Gram-positive bacteria (S. aureus ATCC 6538; AE, 12; EE, 16), whereas AgNPs had a greater effect on Gram-negative bacteria. The MICs (mg/mL) of the AEs varied from 3.125 (S. aureus ATCC 6538) to 12.5 (E. coli 1 and E. coli 2), whereas the MICs of the EEs varied from 1.5625 (S. aureus 1, S. aureus ATCC 6538, and E. faecalis) to 6.25 (E. coli 1). There was a significant difference between the MICs of AEs and EEs (p=0.014). The MBCs (mg/mL) of the AEs varied from 12.5 (S. aureus ATCC 6538) to 50 (S. aureus 1), whereas those of the EEs varied from 6.25 (S. aureus 1) to 25 (E. coli 1 and E. faecalis). Ethanolic grapefruit extracts demonstrated an ability to modulate cefazolin on E. coli and S. aureus but were completely indifferent to ampicillin on E. coli. Conclusion: Grapefruit peel extracts and their AgNPs exhibit antibacterial properties that can be exploited for the synthesis of new antimicrobials and their EEs may be efficiently used synergistically with other antibiotics against bacteria with intermediate susceptibility.


Author(s):  
A.A.J.P. Kumara ◽  
D. L. Jayratne ◽  
G. V. Samaranayake

Euphorbia antiquorum is a large shrub or small tree belonging to the largest and the most diverse family in the plant kingdom, Euphorbiaceae. E. antiquram latex was used as a classical binding agent for the kshara sutra in the management of the anal fistula. In the present study, an attempt was made to evaluate the antimicrobial properties of latex of E. antiquorum on certain microbes. The methanolic extract of the latex was prepared. The fractions of methanol extract were tested for their antibacterial activity against the Gram positive bacteria, Streptococus agalactiae and Staphylococcus aureus and Gram negative bacteria Escherichia coli and P. aeruginosa. The results revealed that the latex showed minimum inhibition only to E. coli and S. aureus. Latex did not posses antibacterial activity against S. agalactiae and P. aeruginosa. The results suggest that the E. antiquorum latex extract account for the antibacterial properties and has a potential for use as an antimicrobial agent.


2020 ◽  
Vol 36 (4) ◽  
pp. 87-93
Author(s):  
V.Yu. Reshetova ◽  
A.F. Krivoshchepov ◽  
I.A. Butorova ◽  
N.B. Feldman ◽  
S.V. Lutsenko ◽  
...  

Chitosan beads with colloidal silver nanoparticles inclued in the polymer matrix have been obtained by the introduction of chitosan into an acidified nanosilver sol. Dual interconnection of drops of the resulting solution was then carried out by ionotropic gelation at the first stage and covalent crosslinking of the polymer matrix with adipic acid at the second stage. The surface morphology of the obtained beads was studied by scanning electron microscopy. Data of Fourier transform IR spectroscopy confirmed the formation of covalent bonds between chitosan and adipic acid. The antibacterial activity of obtained beads against S. aureus and E. coli was evaluated using agar diffusion test. It was shown that the сhitosan beads modified with nanostructured silver exhibited an antibacterial effect against the tested strains, and they can be used as a basis for creating biodegradable wound healing dressings with a prolonged antibacterial effect. chitosan, silver nanoparticles, antibacterial activity, wound dressings This work was supported by the "Russian Academic Excellence Project 5-100". The study was carried out with the financial support of the Russian Foundation for Basic Research in the framework of the Scientific Project no. 18-29-18039.


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