scholarly journals Preparation of the Hybrids of Hydrotalcites and Chitosan by Urea Method and Their Antimicrobial Activities

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1588 ◽  
Author(s):  
Bi Foua Claude Alain Gohi ◽  
Hong-Yan Zeng ◽  
Xiao-Ju Cao ◽  
Kai-Min Zou ◽  
Wenlin Shuai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Surface Properties ◽  
Antimicrobial Agents ◽  
Materials Science ◽  
Mechanical Stability ◽  
Antimicrobial Activities ◽  
Molar Ratio ◽  
Penicillium Cyclopium ◽  
Urea Method

Hybrid nano-supra molecular structured materials can boost the functionality of nano- or supra-molecular materials by providing increased reactivity and conductivity, or by simply improving their mechanical stability. Herein, the studies in materials science exploring hybrid systems are investigated from the perspective of two important related applications: healthcare and food safety. Interfacing phase strategy was applied, and ZnAl layered double hydroxide-chitosan hybrids, prepared by the urea method (U-LDH/CS), were successfully synthesized under the conditions of different chitosan(CS) concentrations with a Zn/Al molar ratio of 5.0. The structure and surface properties of the U-LDH/CS hybrids were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectrometer(FTIR), scanning electronmicroscopy (SEM), ultravioletvisible (UV-Vis), and zero point charge (ZPC) techniques, where the effect of CS concentration on the structure and surface properties was investigated. The use of the U-LDH/CS hybrids as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium was investigated in order to clarify the relationship between microstructure and antimicrobial ability. The hybrid prepared in a CS concentration of 1.0 g∙L−1 (U-LDH/CS1) exhibited the best antimicrobial activity and exhibited average inhibition zones of 24.2, 30.4, and 22.3mm against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium, respectively. The results showed that the appropriate addition of CS molecules could increase antimicrobial ability against microorganisms.

scholarly journals Combination Effects of Cymbopogon sp. Essential Oil on Selected Bacteria

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Nur Aishah Abdul Wahab ◽  
Hairul Shahril Muhamad ◽  
Nabilah Ahmad Alhadi ◽  
Salina Mat Radzi ◽  
Maryam Mohamed Rehan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Essential Oils ◽  
Staphylococcus Epidermidis ◽  
Antimicrobial Agents ◽  
Synergistic Effects ◽  
Combination Effects ◽  
Cymbopogon Flexuosus ◽  
Combination Study

Combination effects between Cymbopogon flexuosus and Cymbopogon nardus essential oils were studied to determine whether the combination could emerge as better and more powerful antimicrobial agents against six selected bacteria includes Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis. This combination study exhibited 40.67% additive, 28.67% antagonistic, 16.00% indifferent and 14.66% synergistic effects. C. flexuosus and C. nardus essential oils in combination showed a high inhibitory activity against S. aureus with 16% synergistic, 64% additive and 20% indifferent effects.

scholarly journals ANTIMICROBIAL POTENTIALS OF SOIL FUNGI METABOLITES, MOLECULAR DYNAMICS AND THEIR 3D PROTEIN STRUCTURAL PREDICTION USING BIOINFORMATICS TOOL

2020 ◽  
pp. 20-26
Author(s):  
MAJOLAGBE O. N. ◽  
AINA D. A. ◽  
OMOMOWO I. O. ◽  
THOMAS A.
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Protein Structure ◽  
Secondary Metabolites ◽  
Soil Fungi ◽  
3D Structure ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
3D Protein Structure ◽  
Klebsiella Spp

Objective: To determine the antimicrobial potentials of secondary metabolite of soil fungi and predict their 3D structure and molecular identity. Methods: Pure soil fungi were isolated from soil samples and cultured under submerged fermentation (Smf) for their metabolites using Potato Dextrose Agar and Broth. The secondary metabolites of the isolated fungi were obtained intracellularly after 21 d of incubation in a rotary shaker incubator. The antimicrobial potentials of the metabolites were investigated against four (4) clinical isolates, namely: Staphylococcus aureus, Klebsiella spp, Candida albicans and Escherichia coli. These soil fungi were further characterized to the molecular level and their evolutionary relationships established using bioinformatics tools. Protein structure of each of the fungi isolates was predicted using PHYRE-2. Results: Out of all the soil fungi isolated, the metabolite of Aspergillus aculeatus showed the highest antimicrobial activities against Staphylococcus aureus (23.00±2.34 mm), Escherichia coli (9.00±1.44 mm) and Klebsiella spp (24.00±3.45 mm). The 3D protein structure predicted showed that each of the organisms consists of different amino-acid compositions such as: serine, tyrosine, proline, arginine, glycine, phenylalanine leucine with other notable biological properties. Conclusion: The work revealed that secondary metabolites of the isolated fungi carry an important role in combating infectious agents thereby, providing roadmaps for the biosynthesis of many synthetic and semi-synthetic drugs and bio-products which are environmentally friendly.

scholarly journals Green synthesis of Ag, Zn and Cu nanoparticles from aqueous extract of Spondias mombin leaves and evaluation of their antibacterial activity

2020 ◽  
Vol 21 (2) ◽  
pp. 106-113
Author(s):  
D.K. Adeyemi ◽  
A.O. Adeluola ◽  
M.J. Akinbile ◽  
O.O. Johnson ◽  
G.A. Ayoola
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Green Synthesis ◽  
Antimicrobial Activities ◽  
Cu Nanoparticles ◽  
E Coli ◽  
Spondias Mombin ◽  
Ft Ir ◽  
Uv Visible

Background: Nanotechnology offers an advantage as a green route for synthesis of metal nanoparticles (NPs) with plant extracts as capping agent. Spondias mombin is a fruit-bearing tree and its leaf extracts have been reported to possess anxiolytic, hypoglycaemic, antiepileptic, antipsychotic, sedative, antioxidant, and antimicrobial properties. The objective of the study is to determine the antibacterial potential of a simple non-toxic product of green synthesis of metallic (Ag, Zn and Cu) nanoparticles using the leaf of Spondias mombin aqueous extracts (SMAE) as a reducing and capping agents of the metal ions.Methodology: Nanoparticles were characterized by UV visible spectrophotometeric analysis, Fourier Transform Infra-Red (FT-IR) spectrophotometer and scanning electron microscope (SEM). Antimicrobial activities of synthesized NPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were determined by agar well diffusion technique.Results: The synthesized NPs varied in colour from dark brown to green and appears dominantly spherical, occasionally rod or triangular shaped with size ranging from 65-90 nm. UV spectroscopy absorption spectra of Ag, Zn and Cu NPs had absorbance peak at 267, 262 and 765 nm respectively. FT-IR spectrometry of Zn NP, Cu NP, and SMAE gave wave number ranging from 895.71-3320.67, 747.02-3225.45 and 658.25-3674.49 respectively. FT-IR analysis showed that SMAE acted as reducing and stabilizing agent while the NPs exhibited lower energy absorption band when compared to the plant extract. The NPs demonstrated higher antimicrobial activities against S. aureus than Ps. aeruginosa and E. coli. The antimicrobial activity was higher with copper NP than Ag and Zn NPs, and also higher than SMAE.Conclusion: The result from this study presents an indication for an alternative means for development of novel antimicrobial agents for clinical and biotechnological applications.Keywords: synthesis, nanoparticles, FT-IR, UV-visible spectrophotometry, antibacterial activitiesFrench Title: Synthèse verte de nanoparticules d'Ag, de Zn et de Cu à partir d'extrait aqueux de feuilles de Spondias mombin et évaluation de leur activité antibactérienneContexte: La nanotechnologie offre un avantage en tant que voie verte pour la synthèse de nanoparticules métalliques (NP) avec des extraits de plantes comme agent de coiffage. Spondias mombin est un arbre fruitier et ses extraits de feuilles possèdent des propriétés anxiolytiques,  hypoglycémiques, antiépileptiques, antipsychotiques, sédatives,  antioxydantes et antimicrobiennes. L’objectif de l’étude est de déterminer le potentiel antibactérien d’un simple produit non toxique de synthèse verte de nanoparticules métalliques (Ag, Zn et Cu) à l’aide de la feuille d’extraits aqueux de Spondias mombin (SMAE) en tant qu’agent réducteur et coiffant de la ions métalliques.Méthodologie: Les nanoparticules ont été caractérisées par analyse  spectrophotométrique UV visible, spectrophotomètre à transformée de Fourier infrarouge (FT-IR) et microscope électronique à balayage (MEB). Lesactivités antimicrobiennes de NP synthétisées contre Escherichia coli, Staphylococcus aureus et Pseudomonas aeruginosa ont été déterminées par une technique de diffusion sur puits d’agar.Résultats: Les NP synthétisés ont une couleur allant du brun foncé au vert et apparaissent principalement sphériques, parfois en bâtonnets ou en triangles, avec des tailles allant de 65 à 90 nm. Les spectres  d'absorption par spectroscopie UV des NP Ag, Zn et Cu présentaient des pics  d'absorbance à 267, 262 et 765 nm respectivement. La spectrométrie FT-IR de Zn NP, Cu NP et SMAE a donné un nombre d'onde allant de 895,71 à 3320,67, 747,02 à 3225,45 et 658,25 à 3674,49 respectivement. L'analyse FT-IR a montré que le SMAE agissait en tant qu'agent réducteur et  stabilisant, alors que les NP présentaient une bande d'absorption d'énergie inférieure à celle de l'extrait de plante. Les NP ont démontré des activités antimicrobiennes plus élevées contre S. aureus que Ps. aeruginosa et E. coli. L'activité antimicrobienne était plus élevée avec les NP en cuivre que dans les NP Ag et Zn, et également supérieure à celle du SMAE.Conclusion: le résultat de cette étude présente une indication d'un autre moyen de développement de nouveaux agents antimicrobiens pour des applications cliniques et biotechnologiques.Mots-clés: synthèse, nanoparticules, FT-IR, spectrophotométrie UV-visible, activités antibactériennes 

scholarly journals Promising Antibiofilm Agents: Recent Breakthrough against Biofilm Producing Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 667 ◽  
Author(s):  
Marwa I. Abd El-Hamid ◽  
El-sayed Y. El-Naenaeey ◽  
Toka M kandeel ◽  
Wael A. H. Hegazy ◽  
Rasha A. Mosbah ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Proteinase K ◽  
Zno Nps ◽  
Methicillin Resistant ◽  
Biofilm Production ◽  
Antibiofilm Agents

Multidrug resistant (MDR) methicillin-resistant Staphylococcus aureus (MRSA) is a superbug pathogen that causes serious diseases. One of the main reasons for the lack of the effectiveness of antibiotic therapy against infections caused by this resistant pathogen is the recalcitrant nature of MRSA biofilms, which results in an increasingly serious situation worldwide. Consequently, the development of innovative biofilm inhibitors is urgently needed to control the biofilm formation by this pathogen. In this work, we thus sought to evaluate the biofilm inhibiting ability of some promising antibiofilm agents such as zinc oxide nanoparticles (Zno NPs), proteinase K, and hamamelitannin (HAM) in managing the MRSA biofilms. Different phenotypic and genotypic methods were used to identify the biofilm producing MDR MRSA isolates and the antibiofilm/antimicrobial activities of the used promising agents. Our study demonstrated strong antibiofilm activities of ZnO NPs, proteinase K, and HAM against MRSA biofilms along with their transcriptional modulation of biofilm (intercellular adhesion A, icaA) and quorum sensing (QS) (agr) genes. Interestingly, only ZnO NPs showed a powerful antimicrobial activity against this pathogen. Collectively, we observed overall positive correlations between the biofilm production and the antimicrobial resistance/agr genotypes II and IV. Meanwhile, there was no significant correlation between the toxin genes and the biofilm production. The ZnO NPs were recommended to be used alone as potent antimicrobial and antibiofilm agents against MDR MRSA and their biofilm-associated diseases. On the other hand, proteinase-K and HAM can be co-administrated with other antimicrobial agents to manage such types of infections.

Synthesis of Nano-Hydroxyapatite from Snakehead (Channa striata) Fish Bone and its Antibacterial Properties

2020 ◽  
Vol 840 ◽  
pp. 293-299
Author(s):  
Poedji Loekitowati Hariani ◽  
Muryati Muryati ◽  
Muhammad Said ◽  
Salni Salni
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Fish Bone ◽  
Molar Ratio ◽  
Temperature Variations ◽  
Gram Negative ◽  
Fish Bones ◽  
Channa Striata

Nano-hydroxyapatite was synthesized by coprecipitation method and tested its antibacterial properties. Nano-hydroxyapatite was synthesized using CaO precursors from snakehead (Channa striata) fish bones and (NH4)2HPO4. The synthesis was carried out with temperature variations of 30, 60, 80, and 100 °C. Antibacterial activity was determined using two types of bacteria, namely gram-positive and gram-negative. The XRD spectra show that the highest peak is hydroxyapatite synthesized at a temperature of 100 °C. Hydroxyapatite produced from various synthesis temperatures has the size of nanoparticles in the range 37.32-49.27 nm. The nano-hydroxyapatite functional groups are characterized using FTIR, the analysis indicate the presence of OH, CO32‒ and PO43‒. The molar ratio Ca/P is obtained of 1.71 approaching theoretical hydroxyapatite of 1.67. The resulted nano-hydroxyapatite has significant antibacterial properties to Escherichia coli and Staphylococcus aureus.

scholarly journals Antimicrobial activities of some mixed ligands adducts of benzoylacetone and salicylaldehyde

2018 ◽  
Vol 11 (1) ◽  
pp. 174-178
Author(s):  
Muhammad Saleh Salga ◽  
Sani Sabo
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Antimicrobial Activities ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Metal Chlorides ◽  
Antimicrobial Studies ◽  
Mixed Ligands

A series of four mixed ligand complexes synthesized by reacting benzoylacetone and salicylaldehyde with different metal chlorides in ethanolic medium, were tested for their antimicrobial studies and indicated that the compounds are active against microorganisms used (Escherichia coli, Staphylococcus aureus, and Candida albicans) when compared with the activity of the reference or standard drugs (Erythromycin and Suptrin).Keywords: Antimicrobial, Synthesis, Ligands, Complexes

One-Step Synthesis and Antibacterial Properties of Polyaniline/TiO2 Nanocomposites

2012 ◽  
Vol 534 ◽  
pp. 78-81
Author(s):  
Ting Wei Hu ◽  
Shao Yun Shan ◽  
Shi Mei Yang ◽  
Li Hong Jiang ◽  
Ya Ming Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Interfacial Polymerization ◽  
Antibacterial Property ◽  
Antibacterial Properties ◽  
Molar Ratio ◽  
Tetrabutyl Titanate ◽  
One Step ◽  
Polymerization Method

Polyaniline(PANI)/TiO2 nanocomposites are successful synthesized by one step-interfacial polymerization method. Morphologies and structures of the nanocomposites are characterized using SEM, FTIR, and XRD. The antibacterial properties of PANI/TiO2 nanocomposites on Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Bacillus megateriu and Bacillus cereus are tested. The effect of molar ratio of aniline and tetrabutyl titanate on structures and antibacterial properties are also been explored. The results show that the content of tetrabutyl titanate has a obvious influence on structure and morphologies of the nanocomposites. PANI/TiO2 nanocomposites have antibacterial properties especially on Staphylococcus aureus and Escherichia coli, which shows a best antibacterial property when the molar ratio of aniline to tetrabutyl titanate is 3:2.

scholarly journals Structure-activity relationships of 3-substituted-5,5- diphenylhydantoins as potential antiproliferative and antimicrobial agents

2011 ◽  
Vol 76 (12) ◽  
pp. 1597-1606 ◽  
Author(s):  
Nemanja Trisovic ◽  
Bojan Bozic ◽  
Ana Obradovic ◽  
Olgica Stefanovic ◽  
Snezana Markovic ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Human Colon ◽  
Antibacterial Activities ◽  
E Coli ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Almost All

A series of twelve 3-substituted-5,5-diphenylhydantoins was synthesized, including some whose anticonvulsant activities have already been reported in the literature. Their antiproliferative activities against HCT-116 human colon carcinoma cells were evaluated to determine structure-activity relationships. Almost all of the compounds exhibited statistically significant antiproliferative effects at a concentration of 100 ?M, while the derivative bearing a benzyl group was active even at lower concentrations. Moreover, their in vitro antibacterial activities against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and clinical isolates of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus were evaluated. Only the 3-iso-propyl and 3-benzyl derivatives showed weak antibacterial activities against the Gram-positive bacterium E. faecalis and the Gram-negative bacteria E. coli ATCC 25922 and E. coli.

scholarly journals Novel synthetic antimicrobial peptides effective against methicillin-resistant Staphylococcus aureus

1994 ◽  
Vol 302 (2) ◽  
pp. 535-538 ◽  
Author(s):  
J Alvarez-Bravo ◽  
S Kurata ◽  
S Natori
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Liquid Medium ◽  
Culture Medium ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Activities ◽  
Methicillin Resistant ◽  
Synthetic Antimicrobial Peptides

Previously, we identified a core undecapeptide of sapecin B having antimicrobial activity. Based on the structure of this peptide, we systematically synthesized peptides consisting of terminal basic motifs and internal oligo-leucine sequences and examined their antimicrobial activities. Of these peptides, RLKLLLLLRLK-NH2 and KLKLLLLLKLK-NH2 were found to have potent microbicidal activity against Staphylococcus aureus, Escherichia coli, methicillin-resistant S. aureus and Candida albicans in liquid medium. We also synthesized the D-enantiomer of KLKLLLLLKLK-NH2. This enantiomer was resistant to tryptic digestion and persisted longer in the culture medium, showing greater antimicrobial activity than the original peptide.

Sign in / Sign up

Export Citation Format

Share Document