scholarly journals Green Synthesis of Silver Nanoparticles Using Novel Launaea Procumbens Leaves Extract and Screening Its Antibacterial Activity

2021 ◽  
Author(s):  
Sanjay Ratan Kumavat ◽  
SATYENDRA MISHRA
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Launaea Procumbens

Abstract Plants are emerging as a cost-effective and ecofriendly method for green synthesis of nanoparticles. The plant extract Launaea procumbens was used as a reduction agent in the green synthesis of silver nanoparticles. UV-Visible spectroscopy, HR-TEM, SAED, FE-SEM, EDAX, DLS, and FT-IR were used to study the green synthesized silver nanoparticles. UV-Vis spectroscopy of a prepared silver solution revealed maximum absorption at 435 nm. The synthesized silver nanoparticles were found to be spherical in shape with a size in the range of 24.28 to 31.54 nm. DLS analysis was used to determine the size of the green synthesized silver nanoparticles, which showed outstanding antibacterial action against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, as well as Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Gram-positive Bacillus subtilis had a maximum zone of inhibition of 20 mm, Staphylococcus aureus had a zone of inhibition of 19 mm, and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa had zones of inhibition of 13 mm.

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.

Green Synthesis of Novel ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl)thiophene-2-carboxylate derivatives

2021 ◽  
pp. 105-110
Author(s):  
Satish M. Chavan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Aspergillus Niger ◽  
Microwave Irradiation ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Green Protocol ◽  
Gram Positive Bacteria

Synthesis of novel ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives from 3-amino-4-carbamoyl-5-(methylthio)thiophene-2-carboxylate was carried out by traditional as well as microwave irradiation green protocol. Ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives were screened for antimicrobial screening against gram positive bacteria Staphylococcus aureus (ATCC 29737), gram negative bacteria Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (MTCC 277), Aspergillus niger (MCIM 545) fungi.

Enhancement of photobactericidal activity of chlorin-e6-cellulose nanocrystals by covalent attachment of polymyxin B

2017 ◽  
Vol 5 (33) ◽  
pp. 6953-6962 ◽  
Author(s):  
Florent Le Guern ◽  
Tan-Sothea Ouk ◽  
Karine Grenier ◽  
Nicolas Joly ◽  
Vincent Lequart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Polymyxin B ◽  
Chlorin E6 ◽  
Covalent Attachment ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria

Following light irradiation, a new nanomaterial, elaborated from CNCs, chlorin-e6 and polymyxin B, demonstrated efficiency against Gram-negative bacteria (Escherichia coli,Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus,Staphylococcus epidermidis).

scholarly journals Essential Oil Composition and Antibacteral Activity of Vismia Baccifera Fruits Collected from Mérida, Venezuela

2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Janne Rojas ◽  
Alexis Buitrago ◽  
Luis Rojas ◽  
Antonio Morales ◽  
María Lucena ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Mass Spectra ◽  
Essential Oil Composition ◽  
Gram Negative Bacteria ◽  
Oil Composition ◽  
Gram Negative

The essential oil from the fruits of Vismia baccifera Triana & Planch. (Gutttiferae), collected in June 2009, was analyzed by GC/MS. A yield of 0.6% oil was obtained by hydrodistillation. Twenty-seven components were identified by comparison of their mass spectra with those in the Wiley GC-MS Library data base. The major components were trans-cadin-1,4-diene (36.6%), cis-cadin-1,4-diene (18.8%) and β-caryophyllene (11.9%). The essential oil showed a broad spectrum of antibacterial activity against the important human pathogenic Gram-positive and Gram-negative bacteria Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25992), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 23357) with MIC values ranging from 9 to 37 μg/mL.

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 Magnitude of Multidrug Resistance among Bacterial Isolates from Surgical Site Infections in Two National Referral Hospitals in Asmara, Eritrea

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Eyob Yohannes Garoy ◽  
Yacob Berhane Gebreab ◽  
Oliver Okoth Achila ◽  
Nobiel Tecklebrhan ◽  
Hermon Michael Tsegai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Surgical Site Infections ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Referral Hospitals

Background. The World Health Organization has emphasized the importance of understanding the epidemiology of MDR organisms from a local standpoint. Here, we report on a spectrum of bacteria associated with surgical site infections in two referral hospitals in Eritrea and the associated antibiotic susceptibility patterns. Methods. This survey was conducted between February and May 2017. A total of 83 patients receiving treatment for various surgical conditions were included. Swabs from infected surgical sites were collected using Levine technique and processed using standard microbiological procedures. In vitro antimicrobial susceptibility testing was performed on Mueller–Hinton Agar by the Kirby-Bauer disk diffusion method following Clinical and Laboratory Standards Institute guidelines. The data were analyzed using SPSS version 20. Results. A total of 116 isolates were recovered from 83 patients. In total, 67 (58%) and 49 (42%) of the isolates were Gram-positive and Gram-negative bacteria, respectively. The most common isolates included Citrobacter spp., Klebsiella spp., Escherichia coli, Proteus spp., Pseudomonas aeruginosa, Salmonella spp., Enterobacter spp., and Acinetobacter spp. In contrast, Staphylococcus aureus, CONS, and Streptococcus viridians were the predominant Gram-positive isolates. All the Staphylococcus aureus isolates were resistant to penicillin. MRSA phenotype was observed in 70% of the isolates. Vancomycin, clindamycin, and erythromycin resistance were observed in 60%, 25%, and 25% of the isolates, respectively. Furthermore, a high proportion (91%) of the Gram-negative bacteria were resistant to ampicillin and 100% of the Pseudomonas aeruginosa and Escherichia coli isolates were resistant to >5 of the tested antibiotics. The two Acinetobacter isolates were resistant to >7 antimicrobial agents. We also noted that 4 (60%) of the Klebsiella isolates were resistant to >5 antimicrobial agents. Possible pan-drug-resistant (PDR) strains were also isolated. Conclusion. Due to the high frequency of MDR isolates reported in this study, the development and implementation of suitable infection control policies and guidelines is imperative.

scholarly journals Experimental implementation of Raman scattering spectroscopy, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique

2021 ◽  
pp. 3-10
Author(s):  
Nadia Mohammed Jassim ◽  
Alyaa Hussein Ali ◽  
Ammar Jassim Mohammed
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Raman Scattering ◽  
Crystallite Size ◽  
Diffraction Measurement ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Raman Scattering Spectroscopy

The object of research is studying Raman scattering technique, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique which independent on a long time, effort, energy and high temperatures, and with the highest adsorption capacity in order to achieve a high inhibition to paralyze the activity of the bacterial wall, by achieving the highest surface plasmon resonance (SRR). Silver nanoparticles were prepared using Matricaria Flower extract. Characterization of silver nanoparticles and detection of their effectiveness against microbial using two types of bacteria (Escherichia Coli and Staphylococcus aureus ), these nanoparticles were measured using a number of measurements, X-ray diffraction measurement, Energy Dispersion (EDX), (FESEM), U–V Spectroscopy, Fourier Transform Infrared (FTIR), Photoluminescence (PL) properties of silver nanoparticle at room temperature and Raman scattering spectroscopy were investigated. The Scherrer’s equation was used to calculate the crystallite size of Silver nanoparticles, the average crystallite size is 48.64 nm. The PL spectra of silver nanoparticles exhibit two emission bands: one is in the UV region 350 nm and the other is in the visible region 650 nm. This is roughly identical to the absorption spectrum results. The antimicrobial activity was tested against gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). Prepared Ag NPs exhibited inhibitory activity in both types of bacteria strains at best selectivity against gram-negative bacteria. An eco-friendly technique is used for synthesizing technique to produce silver nanoparticles with the expected best application properties. These research results suitable to be use the Silver nanoparticles in sensors and many electronic, electrical, medical and biological applications

scholarly journals STUDY OF MICROORGANISMS SUSCEPTIBILITY TO LYSOZYME COMBINATION WITH MEDICINAL SUBSTANCES

2016 ◽  
Author(s):  
I. I. Romanovska ◽  
S. S. Dekina ◽  
І. B. Psakhis ◽  
B. Y. Psakhis
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Antimicrobial Action ◽  
Gram Negative Bacteria ◽  
Chlorhexidine Digluconate ◽  
Disodium Edta ◽  
Gram Negative ◽  
Medicinal Substances

The susceptibility of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans strains to lysozyme, disodium EDTA, chlorhexidine digluconate, and their combinations was studied. It is shown that the addition of chlorhexidine bigluconate wides the spectrum of antimicrobial action of the enzyme in the all cases. The addition of chelator to the composition is effective against gram-negative bacteria Escherichia coli and yeastfungus Candida albicans.

scholarly journals The Immunomodulatory Activity in vitro of NDV ZG1999HDS in Comparison to NDV La Sota

2021 ◽  
Author(s):  
Bratko Filipič ◽  
Lidija Gradišnik ◽  
Adriana Pereyra ◽  
Hrvoje Mazija
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Streptococcus Pyogenes ◽  
Gram Negative Bacteria ◽  
Acinetobacter Baumanii ◽  
Gram Negative ◽  
Gm Csf ◽  
Gram Positive Bacteria ◽  
Streptococcus Mutants

ABSTRACT. The immunotherapies, as a modern therapeutic approach, get an attention because of theirs’ promise to treat a large number of different medical disorders. Immunomodulation effects of low titres (10 HA/ml) of NDV (Newcastle Disease Virus) ZG1999HDS or La Sota were tested on TLT (Human macrophage cell line) bound to PBMC (Peripheral Blood Mononuclear Cells). During the immunomodulation, the amount of NO, H2O2, lysozym and induced antibacterial activity against Gram - positive bacteria (Staphylococcus aureus, MRSA, Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus mutants) and against Gram - negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and Acinetobacter baumanii) were analysed. In addition, the cytokine secretion, IL-1α, IL-2, IL-4, GM-CSF, TNF-α, IFN-α and IFN-α were evaluated. Firstly, the TLT cells are activated through the NDV ZG1999HDS or La Sota binding, followed by the NO “burst” and H2O2 and lysozyme level increase. Secondly, after the binding to the TLT cells and interaction with the PBMCs, the decrease of GM-CSF, and an increase of TNF – α and IFN – γ were found. Simultaneously, the decrease of pro – inflammatory cytokine IFN-α and the differentially increase of IL-1α, IL-2 and IL-4 were recorded. During the induction of the antibacterial response, against Gram - positive bacteria (Staphylococcus aureus, MRSA, Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus mutants) the effect was one third higher with NDV ZG1999HDS compared to La Sota. Antibacterial response against Gram - negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and Acinetobacter baumanii) was not so clear. In general, NDV ZG1999HDS or La Sota activated TLT cells, further bound to PBMC; the ZG1999HDS is stronger immunomodulator than La Sota.

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