scholarly journals ANTIBACTERIAL ACTIVITY OF SELECTIVELY OXIDIZED LYOCELL FIBERS

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Jovana Milanović ◽  
Mirjana Kostić ◽  
Suzana Dimitrijević ◽  
Katarina Popović ◽  
Petar Škundrić
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Nitrate Solution ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Catalytic Amount ◽  
Silver Nitrate Solution ◽  
Silver Particles ◽  
Lyocell Fibers

The purpose of this research was to study antibacterial activity of selectively oxidized lyocell fibers with incorporated silver particles against gram (+) and gram (-) pathogens. Antibacterial properties were accomplished by incorporation of silver ions into modified lyocell fibers by chemisorption from aqueous silver nitrate solution. In order to improve sorption properties of lyocell fibers, the selective TEMPO-mediated oxidation, i.e. oxidation with sodium hypochlorite and catalytic amount of sodium bromide and 2,2´,6,6´-tetramethylpiperidine-1-oxy radical (TEMPO), was applied. The influence of oxidation conditions оn the amount of sorbed silver, and thus on the degree of antibacterial activity was determined. It was found that the maximum amount of sorbed silver was 0.996 mmol/g cell. The antibacterial activity of the TEMPO-oxidized lyocell fibers with silver particles was confirmed in vitro against two strains: Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). The silver-loaded TEMPO-oxidized lyocell fibers showed better antimicrobial activity against strain Staphylococcus aureus.

scholarly journals Antimicrobial TEMPO-oxidized hemp fibers with incorporated silver particles

2012 ◽  
Vol 77 (12) ◽  
pp. 1759-1773 ◽  
Author(s):  
Jovana Milanovic ◽  
Tatjana Mihailovic ◽  
Katarina Popovic ◽  
Mirjana Kostic
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Hypochlorite ◽  
Nitrate Solution ◽  
Catalytic Amount ◽  
Silver Particles ◽  
Experimental Conditions ◽  
Hemp Fibers ◽  
Maximum Sorption Capacity ◽  
Mediated Oxidation

In this paper, the preparation of the antimicrobial silver loaded hemp fibers were carried out by selective TEMPO-mediated oxidation, i.e. oxidation with sodium hypochlorite and catalytic amount of sodium bromide and 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO), followed by silver sorption from aqueous silver nitrate solution. The most suitable experimental conditions for the selective TEMPO-mediated oxidation were determined by changing oxidation conditions: concentration of sodium hypochlorite and duration of sorption. The obtained results showed that the maximum sorption capacity (0.703 mmol of silver per gram of fibers) of modified hemp fibers was obtained for the sample modified with 9.67 mmol NaClO per gram of fibers, during 4 hours. SEM microphotographs of the modified hemp fibers with incorporated silver showed uniformly distributed silver particles on the surface of fibers, with isometric shapes and sizes from 10 to 100 nm, despite the fact that silver was sorbed from ionic solution. The antibacterial activity of the TEMPO-oxidized hemp fibers with silver particles was confirmed in vitro against two strains: Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), and the antifungal activity against fungi Candida albicans (ATCC 24433). The best antimicrobial activity of silver-loaded TEMPO-oxidized hemp fibers was showed against strain Staphylococcus aureus.

scholarly journals Aktivitas Antibakteri Komposit Ag – Tulang Ikan Cakalang pada Staphylococcus aureus

Jurnal MIPA ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 29
Author(s):  
Elmi C.J. Pandelaki ◽  
Audy D. Wuntu ◽  
Henry F. Aritonang
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Food Industry ◽  
Mixing Time ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Inhibition Zone ◽  
Skipjack Tuna ◽  
Fish Bones

Telah dilakukan penelitian untuk mengetahui aktivitas antibakteri komposit Ag – tulang ikan cakalang pada Staphylococcus aureus. Tulang ikan cakalang dikeringkan, dihaluskan dan diayak 65 mesh kemudian dicampur dengan larutan perak nitrat dengan perbandingan Ag : tulang ikan sebesar 5:1 , 4:2, dan 3:3  selama 1 jam pada suhu 70 ℃. Campuran kemudian di kalsinasi pada suhu 650 ℃ selama 2 jam. Uji aktivitas antibakteri dari komposit yang terbentuk dikerjakan dengan metode sumuran menggunakan bakteri Staphylococcus aureus. Hasil penelitian menunjukkan aktivitas antibakteri pada perbandingan 4:2 dengan lama waktu pencampuran 1 jam paling efektif untuk menghambat bakteri Staphylococcus aureus dengan diameter zona hambat sebesar 25 mm. Penelitian ini menunjukkan valorisasi dari produk sampingan industri makanan seperti tulang ikan untuk membentuk bahan yang berpotensi berharga sebagai bahan implan tulang yang resistan terhadap infeksi bakteriResearch has been conducted to determine the antibacterial activity of Ag - Bone skipjack tuna toward Staphylococcus aureus. Skipjack tuna bone dried, mashed and sifted 65 mesh then mixed with silver nitrate solution with a ratio of Ag : fish bones of 5:1, 4:2, and 3:3 for 1 hour at 70 ℃. The mixture was then calcined at 650 ℃ for 2 hours. Antibacterial activity test of the composites formed was done by the method of wells using the bacteria Staphylococcus aureus. The results showed that antibacterial activity at a ratio of 4: 2 with a one-hour mixing time was most effective for inhibiting Staphylococcus aureus bacteria with a 25 mm inhibition zone diameter. This study shows the valorization of food industry byproducts such as fish bones to form potentially valuable ingredients for bone implants resistant to bacterial infections

Fabrication of hydroxyapatite microparticles including silver nano-dots at grain boundary for long-term antimicrobial property

MRS Advances ◽  
2016 ◽  
Vol 2 (24) ◽  
pp. 1285-1290
Author(s):  
Hiroaki Igashira ◽  
Michimasa Kamo ◽  
Masayuki Kyomoto ◽  
Toshiyuki Ikoma
Keyword(s):  
Grain Boundary ◽  
Silver Nitrate ◽  
Silver Oxide ◽  
Antimicrobial Property ◽  
Nitrate Solution ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Silver Nitrate Solution ◽  
Silver Phosphate

ABSTRACTThe antibacterial properties are useful to restrain inflammatory response caused by bacterial infection after implantation. The composites of hydroxyapatite (HAp) and silver nano-dots, silver oxide or silver phosphate have been investigated; however there are still some disadvantage in sintering; 1) silver nano-dots grow large, and are not homogenously distributed, 2) silver nano-dots melt and remove, and 3) silver phosphate and silver oxide formed exhibit higher solubility than metal silver. In this study, the distribution of silver nano-dots in HAp microparticles sintered was controlled at grain boundary with a modified silver mirror reaction as a novel route. HAp microparticles adsorbed formaldehyde by a vapor deposition method were soaked in an ammoniacal silver nitrate solution and were then sintered. There was a single phase of HAp including metal silver at 6.4 wt% even after sintering. The silver nano-dots were homogeneously distributed inside the microparticles. The release profiles of silver ions in phosphate buffer saline were compared with a reference; the HAp microparticles were soaked into silver nitrate solution and were then sintered. The distribution of silver in the reference was not homogeneous and large silver microparticles were grown outside the particles at 6.3wt%. The elution amount of silver ions from the microparticles at 12 hours was one-eighteenth of that from the reference. These results suggest that the HAp microparticles including silver nano-dots at grain boundary will be suitable for a long-term antibacterial material.

scholarly journals Screening phytochimique des extraits méthanoliques des feuilles de Combretum collinum et des racines de Anogeisus leiocarpus et effet antibactérien in vitro sur des souches de Staphylococcus aureus multirésistantes

2020 ◽  
Vol 14 (6) ◽  
pp. 2362-2372
Author(s):  
Moussa Bamba ◽  
Christel Neut ◽  
Simon Bordage ◽  
Soro Dramane ◽  
Jules Kouadio N’guessan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Dilution Method ◽  
Plantes Médicinales ◽  
Phytochemical Screening ◽  
Methanolic Extracts ◽  
Anogeissus Leiocarpus

Anogeissus leiocarpus (DC.) Guill. & Perr. (Combretaceae) et Combretum collinum Fresen. (Combretaceae) sont deux plantes de la flore ivoirienne couramment utilisées pour traiter plusieurs pathologies telles que les affections cutanées, le paludisme et la fatigue générale. Ce travail s’inscrit dans le cadre de la valorisation de cette flore. Il vise donc à évaluer l’activité antibactérienne des extraits méthanoliques bruts des feuilles de Combretum collinum et des écorces de racines de Anogeissus leiocarpus sur la croissance "in vitro" des souches de Staphylococcus aureus résistantes à la méticilline. La méthode de diffusion en milieu gélosé (solide) a été utilisée pour évaluer la sensibilité des souches bactériennes aux extraits et à déterminer les concentrations minimales inhibitrices (CMI), Quant au screening phytochimique, il a été réalisé par une chromatographie sur couche mince (CCM). La concentration minimale inhibitrice est comprise entre 0,62 mg/ml et 1,25 mg/ml pour Anogeissus leiocarpus et est de 0,325 mg/ml pour Combretum collinum. Le screening phytochimique a révélé la présence de flavonoïdes et de tanins dans l’extrait méthanolique de Anogeissus leiocarpus alors que dans l’extrait méthanolique de Combretum collinum, ce sont des acides phénoliques qui ont été mis en évidence. Il ressort donc que ces deux plantes sont dotées d’un important pouvoir antibactérien et contiennent plusieurs composés chimiques. Elles pourraient donc constituer des voies de prospection pour la recherche de nouvelles molécules antibactériennes en réalisant une étude bio-guidée des extraits bruts et en évaluant leur cytotoxicité sur des cellules hépatiques saines.Mots clés: Antibactérienne, plantes médicinales, flore ivoirienne, extraits methanoliques English Title: Phytochemical screening of methanolic extracts from leaves of Combretum collinum and roots of Anogeisus leiocarpus and in vitro antibacterial effect on multiresistant strains of Staphylococcus aureus Both Anogeissus leiocarpus (DC.) Guill. & Perr. (Combretaceae) and Combretum collinum Fresen. (Combretaceae) are Ivorian national flora plants commonly used in treating skin disorders, malaria, and general fatigue. The current study consists of the valorization of this flora, and aims therefore at revealing antibacterial activity of the methanol crude extracts obtained from stem bark and leaves of the respective plants, against Methicillin-resistant Staphylococcus aureus strains. Agar gel diffusion method was used to assess bacteria susceptibility, and broth dilution method allowed determination of minimum inhibition concentrations (MICs). These parameters varied from 0.62 mg/ml to 1.25 mg/ml for Anogeissus leiocarpus, while they reached 0.325 mg/ml for Combretum collinum. In addition, phytochemical screening brought about flavonoids and tanins for the plant, and phenolic acids for the other one. In conclusion, these named plants contain several chemical compounds with antibacterial properties, and could be of great interest in the search of new molecular compounds provided with antibacterial activity through bio-guided experiments. Furthermore, they could best hold value by testing those methanol extracts over hepatic sane cells for cytotoxicity assessment. Keywords: antibacterial, medicinal plants, Ivorian national flora, methanolic extracts.    

scholarly journals In Vitro Antibacterial Activity of Different Honey Samples Against Clinical Isolates

2021 ◽  
Author(s):  
Mahasin Ahmed Wadi
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Salmonella Typhi ◽  
Clinical Isolates ◽  
Base Line ◽  
Drug Resistant ◽  
Low Sensitivity

Abstract BackgroundThe emergence of multi–drug resistant organisms has created a lot of clinicalproblems. Hence there is a need to find natural alternative treatment to counter the multi–drug resistant organisms. Honey has a well-established usage as wound dressing in ancient and traditional medicine. The aim of this work is to establish a base-line of the antibacterial activity of 32 natural and commercial various honey samples against 8 clinical isolates.MethodsThirty two honey samples (raw and commercial honey) collected from different countries with different floral origin were tested in vitro for antibacterial activity against 8 clinical isolates collected from patients, at private Hospital from Sudan, using disk diffusion technique. The following 6 Epsilometer test (E Test), Amoxicillin, Augamentin, Ceftaxime, Chloramphenicol, Gentamicin and tetracycline were used against 8 clinical isolates for Minimum Inhibitory Concentration.ResultsThe following 8 clinical isolates were identified by conventional bacteriological methods; Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aerouginosa, Proteus.vulgaris, Salmonella typhi, Shigella sonnei and Methicillin Resistant Staphylococcus aureus (MRSA). Honey has been shown to have antibacterial properties against both Gram-positive and Gram-negative bacteria. The tested organisms showed low sensitivity to antibiotics E test.ConclusionMost of the bacterial species studied were uniformly receptive to all the tested honey. In contrast The tested organisms showed low sensitivity to antibiotics with low MIC.

Synthesis of Silver Particles by Replacement Reaction

2013 ◽  
Vol 745-746 ◽  
pp. 72-77
Author(s):  
Chuan Yun Wan ◽  
Wei Zhan
Keyword(s):  
Equilibrium Condition ◽  
Nitrate Solution ◽  
Particle Morphology ◽  
Silver Ions ◽  
Silver Nitrate Solution ◽  
Silver Particles ◽  
Replacement Reaction ◽  
Copper Metal ◽  
Synthesis Conditions ◽  
Dendritic Structures

Silver particles were synthesized by reducing silver ions with copper metal. The as-synthesized silver particles were characterized by scanning electron microscope (SEM). The effects of synthesis conditions on particle morphology were studied. The results showed that dendritic structures were readily synthesized when the silver nitrate solution kept stationary. The low concentration of silver ion was benefit to get perfect silver dendrite. The use of ammonium made the silver shape transferring from dendritic to spherical. The ultrasonic wave accelerated the diffusion of mass and produced spherical silver particles. These results indicated that dendritic silver particles were easy to obtain in non-equilibrium condition while the shape of silver rod-like or spherical was easy to get in equilibrium condition. The morphology and the size of silver particles depend on the synthesis conditions. The formation mechanism of dendritic silver particles were also deduced.

scholarly journals Polyprenols ofGinkgo bilobaEnhance Antibacterial Activity of Five Classes of Antibiotics

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ran Tao ◽  
Chengzhang Wang ◽  
Jianzhong Ye ◽  
Hao Zhou ◽  
Hongxia Chen
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Ginkgo Biloba ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Average Diameter ◽  
Antibiotic Use ◽  
Gentamicin Sulfate ◽  
Mic Value

Polyprenol (GBP) fromGinkgo bilobaLeaves (GBL) is an important lipid with many bioactive effects. The effect of GBP on antibacterial properties of five antibiotics belonging to different classes was through analysis of inhibition halos, MIC, and FIC index. And we studied the time-killing curves and Ca2+mobilization assay inStaphylococcus aureuscells treated with GBP microemulsion and gentamicin sulfate under MIC/2 conditions. These results showed that the GBP microemulsion (average diameter 90.2 nm) combining with gentamicin sulfate had the highest enhancing antibacterial effect againstStaphylococcus aureus, and the MIC value was 33.0 μg/mL. The increase of the antibacterial effect of tested antibiotics was positively correlated with the decrease of the average diameter of GBP microemulsion. Moreover, GBP microemulsion enhanced antibacterial effect and prolonged antibacterial time of GBP combining with gentamicin sulfate againstStaphylococcus aureus. GBP microemulsion could enhance the ability of gentamicin inducing an increase in intracellular calcium concentrations toStaphylococcus aureus. GBP microemulsion could help some classes of antibiotics to inhibit or kill bacteria. This study supports the fact that GBP microemulsion obviously can not only reduce the dosage of some classes of antibiotics, but also reduce the frequency of the antibiotic usein vitro.

scholarly journals INHIBITORY EFFECT OF ONION (ALLIUM CEPA LINN) AND SUGAR PASTE MIXTURE ON STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI BY IN VITRO

2019 ◽  
Vol 5 (4) ◽  
pp. 131-137
Author(s):  
Tahiruddin Tahiruddin ◽  
Diah Indriastuti
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Allium Cepa ◽  
Antibacterial Properties ◽  
Inhibition Zone ◽  
Control Group ◽  
Control Group Design ◽  
Onion Extract

Background: Staphylococcus aureus and Escherichia coli are infection agents. The onion is known to have antibacterial properties. Meanwhile, sugar paste is effective to inhibit bacterial growth.Objective: This study aimed to identify the antibacterial activity of onion extract (Allium cepa Linn) and sugar paste mixture on staphylococcus aureus and Escherichia coli by in vitro.Methods: We used a post-test-only control group design with a completely random design. The onion extract with sugar paste mixture was divided into 4 concentrations; 25%, 50%, 75% and 100% with 3 repetitions. The data were analyzed by measuring inhibition zone diameter and tested using the One-Way Analysis of Variance (ANOVA) and Tukey test.Results: Findings showed that on average, the antibacterial activity of onion extract and sugar paste mixture on staphylococcus aureus was 14.57mm, 17.44mm, 18.36mm, and 22.28mm, respectively 25%, 50%, 75%, and 100% concentrations. Meanwhile, on Escherichia coli, it was 17.27mm, 19.67mm, 20.31mm, and 21.62mm.Conclusion: onion extract and sugar paste mixture can inhibit the growth of Staphylococcus aureus and Escherichia coli.

scholarly journals In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Load ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Biofilm Model ◽  
Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

Sign in / Sign up

Export Citation Format

Share Document