scholarly journals Oxidative Stress and Antimicrobial Activity of Chromium(III) and Ruthenium(II) Complexes onStaphylococcus aureusandEscherichia coli

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Paulina L. Páez ◽  
Claudia M. Bazán ◽  
María E. Bongiovanni ◽  
Judith Toneatto ◽  
Inés Albesa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Agents ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Diimine Ligands

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. The main aim of this work was to establish the potential of the syntheticα-diimine chromium(III) and ruthenium(II) complexes (where theα-diimine ligands are bpy = 2,2-bipyridine, phen = 1,10-phenanthroline, and dppz = dipyrido[3,2-a:2′,3′-c]-phenazine) like [Cr(phen)3]3+, [Cr(phen)2(dppz)]3+, [Ru(phen)3]2+, and [Ru(bpy)3]2+as antibacterial agents by generating oxidative stress. The [Cr(phen)3]3+and [Cr(phen)2(dppz)]3+complexes showed activity against Gram positive and Gram negative bacteria with minimum inhibitory concentrations (MICs) ranging from 0.125 μg/mL to 1 μg/mL, while [Ru(phen)3]2+and [Ru(bpy)3]2+do not exhibit antimicrobial activity against the two bacterial genera studied at the concentration range used. When ciprofloxacin was combined with [Cr(phen)3]3+for the inhibition ofStaphylococcus aureusandEscherichia coli, an important synergistic effect was observed, FIC 0.066 forS. aureusand FIC 0.064 forE. coli. The work described here shows that chromium(III) complexes are bactericidal forS. aureusandE. coli. Our results indicate thatα-diimine chromium(III) complexes may be interesting to open new paths for metallodrug chemotherapy against different bacterial genera since some of these complexes have been found to exhibit remarkable antibacterial activities.

scholarly journals 5-Bromo-1-(4-chlorobenzyl)-1H-indole-2-carboxamides as new potent antibacterial agents

2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Internal Standards ◽  
Gram Negative ◽  
E Coli ◽  
High Antibacterial Activity

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.

Synthesis and antimicrobial activity of 4-trifluoromethylpyridine nucleosides

2017 ◽  
Vol 23 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Shaikha S. Alneyadi ◽  
Anas A. Abdulqader ◽  
Alaa A. Salem ◽  
Ibrahim M. Abdou
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Stenotrophomonas Maltophilia ◽  
Antibacterial Agents ◽  
Antibacterial Activities ◽  
Nucleoside Analogues ◽  
Reference Drug ◽  
Minimum Inhibitory Concentrations

Abstract4-Trifluoromethylpyridine derivatives 4–8 represent good candidates for the discovery of new antibacterial agents. Fluorinated pyridine nucleosides 4–7 and non-nucleoside analogues 8a,b were synthesized and evaluated for their antibacterial activities against Staphylococcus aureus, Bacillus infantis, Escherichia coli and Stenotrophomonas maltophilia. The minimum inhibitory concentrations (MICs) of the new nucleosides 4–7 range from 1.3 to 4.9 μg/mL and MICs of fluoroaryl derivatives 8a,b are in the range of 1.8–5.5 μg/mL. Activity of amoxicillin, the reference drug, is 1.0–2.0 μg/mL under similar conditions.

Composition and Antimicrobial Activity of the Essential Oil of a Wild Kiwi

2011 ◽  
Vol 322 ◽  
pp. 160-163
Author(s):  
Yin Lu ◽  
Hong Chen
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Fungal Species ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Leaf Oil ◽  
First Time

A medicinal wild kiwi in China, Actinidia valvata Dunn, has been well known for its activities against leprosy and cancers. The compositions and the antimicrobial activity of its leaf oil were reported for the first time. The oil obtained by hydrodistillation and analyzed by GC and GC-MS, was characterized by the high content of monoterpenes. Linalool (48.14%) is the major component identified, followed by 1,2-dimethyl-lindoline (7.94%), linolenic acid methylester (6.57%) and (E)-phytol (5.29%). The antimicrobial activity of the oil was evaluated against four bacterial and three fungal species. The results showed that it exhibited a mild antibacterial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), a significant activity against Gram-negative bacteria (Escherichia coli), and no activity on Pseudomonas aeruginosa. The test fungi were more sensitive to the oil, with a MIC range of 0.78~1.56 μL/mL than bacteria in the range which were significantly higher from 0.78 to 25.50 μL/mL.

scholarly journals Green Synthesis, Antioxidant and Antimicrobial Activity of Silver Nanoparticles Using Gnetum africanum Extracts

2021 ◽  
pp. 1-7
Author(s):  
I. M. Uneze ◽  
J. O. Otonko ◽  
A. K. Adigun ◽  
S. J. Adebayo
Keyword(s):  
Escherichia Coli ◽  
Aqueous Solution ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria

The synthesis and application of nanoparticles is an important area of research that is gaining attention recently. In this recent project, we report the synthesis of silver nanoparticles, AgNP using aqueous solution of silver nitrate and Gnetum africanum leaf extract (reducing agent). The synthesis of AgNP was achieved by mixing aqueous solution of silver nitrate (70ml, 15.75mM) with a solution of Gnetum africanum leaf extract 100 ml) in a reaction flask and allowed to stand for 24 hours in a dark cupboard. A color change from light brown to yellowish brown was observed which indicated that synthesis of silver nanoparticles took place. The presence of AgNP was ascertained using UV-vis spectra analysis and absorption at 442 nm showed the presence of AgNP. The antioxidant assay of both the synthesized AgNP and the leaf extract was determined using DPPH. Antimicrobial activity was conducted using three different organisms which were Staphylococcus aureus, Escherichia coli and Pseudomonas respectively. The antioxidant results using DPPH scavenging ability of AgNp showed that at concentrations of 2mg/ml,1mg/ml and 0.1mg/ml, the percentage inhibition  of  DPPH  by AgNp was 61.69, 53.06 and 38.31 respectively and that of Gnetum africanum leaf extract was 81.32, 78.49, and 58.29 respectively at the same concentrations using Ascorbic acid as a standard. The antimicrobial activity of both the synthesized AgNps and Gnetum Africanum Leaf extract using one gram positive bacteria (Staphylococcus aureus) and two gram negative bacteria (Escherichia coli and Pseudomonas) revealed that the synthesized AgNps showed lesser activity than Gnetumafricanum leaf extract for both the gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Pseudomonas) and (Escherichia coli). From the above findings, it can be observed that Gnetum Africanum Leaf extract reduced Ag+ to Ag0 and also both the synthesized AgNps and the Gnetum Africanum Leaf extract showed reasonable antioxidant activity against DPPH and antimicrobial activity against the tested microorganisms. This implied that both samples have medicinal values.

scholarly journals Purification and Properties of Proline-Rich Antimicrobial Peptides from Sheep and Goat Leukocytes

1999 ◽  
Vol 67 (8) ◽  
pp. 4106-4111 ◽  
Author(s):  
Olga Shamova ◽  
Kim A. Brogden ◽  
Chengquan Zhao ◽  
Tung Nguyen ◽  
Vladimir N. Kokryakov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Host Defense ◽  
Defense Mechanisms ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Purification And Properties

ABSTRACT We purified three proline-rich antimicrobial peptides from elastase-treated extracts of sheep and goat leukocytes and subjected two of them, OaBac5α and ChBac5, to detailed analysis. OaBac5α and ChBac5 were homologous to each other and to bovine Bac5. Both exhibited potent, broad-spectrum antimicrobial activity under low-concentration salt conditions. While the peptides remained active againstEscherichia coli, Pseudomonas aeruginosa,Bacillus subtilis, and Listeria monocytogenesin 100 mM NaCl, they lost activity against Staphylococcus aureus and Candida albicans under these conditions. ChBac5 was shown to bind lipopolysaccharide, a property that could enhance its ability to kill gram-negative bacteria. Proline-rich Bac5 peptides are highly conserved in ruminants and may contribute significantly to their innate host defense mechanisms.

scholarly journals Addition of L-cysteine to the N- or C-terminus of the all-D-enantiomer [D(KLAKLAK)2] increases antimicrobial activities against multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10176
Author(s):  
Maki K. Ohno ◽  
Teruo Kirikae ◽  
Eisaku Yoshihara ◽  
Fumiko Kirikae ◽  
Isao Ishida
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Cysteine Residue ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
C Terminus

Background Antimicrobial peptides have a broad spectrum of antimicrobial activities and are attracting attention as promising next-generation antibiotics against multidrug-resistant (MDR) bacteria. The all-d-enantiomer [D(KLAKLAK)2] has been reported to have antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa, and to be resistant to protein degradation in bacteria because it is composed of D-enantiomer compounds. In this study, we demonstrated that modification of [D(KLAKLAK)2] by the addition of an L-cysteine residue to its N- or C- terminus markedly enhanced its antimicrobial activities against Gram-negative bacteria such as MDR Acinetobacter baumannii, E. coli, and P. aeruginosa. Methods The peptides [D(KLAKLAK)2] (DP), DP to which L-cysteine was added at the N-terminus C-DP, and DP to which L-cysteine was added at the C-terminus DP-C, were synthesized at >95% purity. The minimum inhibitory concentrations of peptides and antibiotics were determined by the broth microdilution method. The synergistic effects of the peptides and the antibiotics against MDR P. aeruginosa were evaluated using the checkerboard dilution method. In order to assess how these peptides affect the survival of human cells, cell viability was determined using a Cell Counting Kit-8. Results C-DP and DP-C enhanced the antimicrobial activities of the peptide against MDR Gram-negative bacteria, including A. baumannii, E. coli, and P. aeruginosa. The antimicrobial activity of DP-C was greater than that of C-DP, with these peptides also having antimicrobial activity against drug-susceptible P. aeruginosa and drug-resistant P. aeruginosa overexpressing the efflux pump components. C-DP and DP-C also showed antimicrobial activity against colistin-resistant E. coli harboring mcr-1, which encodes a lipid A modifying enzyme. DP-C showed synergistic antimicrobial activity against MDR P. aeruginosa when combined with colistin. The LD50 of DP-C against a human cell line HepG2 was six times higher than the MIC of DP-C against MDR P. aeruginosa. The LD50 of DP-C was not altered by incubation with low-dose colistin. Conclusion Attachment of an L-cysteine residue to the N- or C-terminus of [D(KLAKLAK)2] enhanced its antimicrobial activity against A. baumannii, E. coli, and P. aeruginosa. The combination of C-DP or DP-C and colistin had synergistic effects against MDR P. aeruginosa. In addition, DP-C and C-DP showed much stronger antimicrobial activity against MDR A. baumannii and E. coli than against P. aeruginosa.

scholarly journals Antibacterial Activity of Borassus flabellifer Vinegar-Graphene Quantum Dots Against Gram-Positive and Gram-Negative Bacteria

2021 ◽  
Vol 33 (11) ◽  
pp. 2662-2666
Author(s):  
Amnuay Noypha ◽  
Paweena Porrawatkul ◽  
Nongyao Teppaya ◽  
Parintip Rattanaburi ◽  
Saksit Chanthai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Antibacterial Activity ◽  
Graphene Quantum Dots ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Borassus flabellifer vinegar–graphene quantum dots (BFV-GQDs) were successfully synthesized using a pyrolysis method with Borassus flabellifer vinegar (BFV) as the precursor. All the samples were characterized using ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activities of BFV-GQDs against strains of Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were determined using the agar well diffusion method for preliminary screening, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the broth macro-dilution method. The zones of inhibition were compared with those of citric acid–graphene quantum dots (CA-GQDs). It was observed that the synthesized BFV-GQDs demonstrated excellent antibacterial activity against Staphylococcus aureus (82.3%) and good antibacterial activity against Escherichia coli (73.3%). The MIC of BFV-GQDs against E. coli was 6.25 mg/mL and S. aureus was 12.5 mg/mL, whereas the MBC of BFV-GQDs against E. coli was 12.5 mg/mL and S. aureus was 25.0 mg/mL.

scholarly journals SINTESIS NANOPARTIKEL KOBALT FERRIT (CoFe2O4) MENGGUNAKAN EKSTRAK DAUN BINAHONG (Anredera cordifolia (Ten) Steenis) DAN APLIKASINYA SEBAGAI ANTIBAKTERI

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Charissa L. Luntungan ◽  
Henry F. Aritonang ◽  
Vanda S. Kamu
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Clear Zone ◽  
Cofe2o4 Nanoparticles ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

ABSTRAKTelah dilakukan penelitian mengenai sintesis nanopartikel CoFe2O4 menggunakan ekstrak daun binahong (Anredera cordifolia (Ten) Steenis). dengan variasi perbandingan mol (Co(NO3)2.6H2O) : (Fe(NO3)3.9H2O) = 1:1 dalam 15 mL. Nanopartikel tersebut dikarakterisasi menggunakan XRD dan SEM serta diuji aktivitas antibakterinya. Uji aktivitas antibakteri mengunakan bakteri Staphylococcus aureus (gram-positif) dan Escherichia coli (gram-negatif). Hasil penelitian menunjukan bahwa ukuran nanopartikelnya adalah 37,52 nm. Kemudian aktivitas antibakteri diketahui berdasarkan luasnya zona bening yang terbentuk dengan hasil diperoleh sebesar 15 mm untuk bakteri E.coli dan 20 mm untuk bakteri S.aureus. Daun Binahong sendiri memiliki sifat sebagai antibakteri dengan hasil yang didapat adalah 8,25 mm untuk bakteri E.coli  dan 10,25 mm untuk bakteri S.aureus. Hal ini menunjukan bahwa nanopartikel CoFe2O4 1 : 1 dalam 15 mL ekstrak dapat digunakan sebagai antibakteriABSTRACTIt has been done research on the synthesis of CoFe2O4 nanoparticles using binahong (Anredera cordifolia (Ten) Steenis) leaf extract. With comparison mol variation of (Co(NO3)2.6H2O) : (Fe(NO3)3.9H2O) = 1:1 in 15 mL extract. The nanoparticles were characterized using XRD and SEM and tested for their antibacterial activities. Test antibacterial activity using Staphylococcus aureus (gram-positive) bacteria and Escherichia coli (gram-negative). The results showed that the nanoparticle size was 37.52 nm. Antibacterial activity is known by the extent of the clear zone formed with the results obtained by 15 mm for the E. coli bacteria and 20 mm for the bacteria S. aureus. The leaf Binahong itself has a trait as an antibacterial with the results obtained is 8.25 mm for the bacteria E. coli and 10.25 mm for the S.aureus bacteria. This suggests that the CoFe2O4 nanoparticles 1:1 mol in 15 mL extrack are used as antibacterial. 

scholarly journals SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON CERTAIN SUBSTITUTED ARYLAZO IMIDAZOLE CONTAINING OXADIAZOLES

2012 ◽  
Vol 20 (20) ◽  
pp. 11-24
Author(s):  
Sreedevi MEESRAGANDA ◽  
Raghavendra Gum Prasad ALURU ◽  
Spoorthy Yadan NARASIMBA ◽  
Ravindnmath Laxmana Rao Krishna RAO
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Dilution Method ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Antimicrobial Studies ◽  
Serial Dilution Method

A series of novel substituted l-[5-(2-methyl-5-nitro-4phenyl-imidazol-lyl methyl)-2-phenyl-(1,3,4)oxadiazol-3-yl]-ethanones have been synthesized. Formation of 1,3,4-oxadiazole ring was accomplished by the reaction of the corresponding hydrazide with acetic anhydride. The structure determination of these compounds has been made on the basis of IR, 1H NMR, and elemental analysis. All the compounds were screened for their antibacterial activity. The antimicrobial activity of title compounds were examined against two gram-negative (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and antifungal activity was carried out against Candida albicans. The MIC values for the newly synthesized compounds have been assessed by serial dilution method All the compounds demonstrated potent antibacterial activity.

scholarly journals SINTESIS NANOKOMPOSIT ZnO-MgO DAN ANALISIS EFEKTIVITAS SEBAGAI ANTIBAKTERI

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jessica Rompis ◽  
Henry Aritonang ◽  
Julius Pontoh
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Staphylococcus Aureus ◽  
Gram Negative Bacteria ◽  
Clear Zone ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Telah dilakukan penelitian mengenai sintesis nanokomposit ZnO-MgO dan analisis efektivitasnya sebagai antibakteri dengan variasi berat Mg(NO3)2 .6H2O (1% & 2%) yang diambil dari berat Zn(NO3)2.4H2O. Nanokomposit tersebut dikarakterisasi menggunakan XRD dan EDS serta diuji efektivitas antibakterinya. Uji efektivitas antibakteri mengunakan bakteri Staphylococcus aureus (Gram-positif) dan Escherichia coli (Gram-negatif). Hasil penelitian menunjukan bahwa ukuran nanopartikelnya adalah 17,41 nm, dan 16,84 nm,. Kemudian efektivitas antibakteri diketahui berdasarkan luasnya zona bening yang terbentuk dan diperoleh masing-masing sebesar 16,7 mm, dan 17,9 mm,  untuk bakteri E.coli dan 15 mm, 15,8 mm, untuk bakteri S.aureus. Nanokomposit ZnO-MgO lebih efektif dalam menghambat pertumuhan bakteri E.coli dibandingkan dengan bakteri S.aureus.ABSTRACT Research on the synthesis of ZnO-MgO nanocomposites and analysis of its effectiveness as an antibacterial has been carried out with variations in molecular weight of Mg (NO3) 2.6H2O (1%, & 2%) taken from the weight of Zn (NO3) 2.4 H2O.The nanocomposites were characterized using XRD and EDS and tested for their antibacterial effectiveness.Antibacterial effectiveness test using Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria. The results showed that the size of the nanoparticles were 17.41 nm,  and 16.84 nm,. Then the effectiveness of antibacterial is known based on the extent of the clear zone formed and obtained respectively of 16.7 mm, and 17.9 mm, for bacteria E. coli and 15 mm, and 15.8 mm for S.aureus bacteria.

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