Biofabricated silver nanoparticles exhibit broad-spectrum antibiofilm and antiquorum sensing activity against Gram-negative bacteria

Secondary metabolites from the shoots and roots of three Rumex species collected from three different habitats were investigated (Rumex dentatus collected from cultivated land, R. pictus collected from the coastal desert and R. vesicarius collected from the inland desert) and tested for antioxidant activity as well as for anti-microbial activity against some human pathogenic bacteria. The present study indicated that the quantitative analysis of shoot and root extracts of three Rumex spp. were found to be rich in tannins and phenolics composition. The aerial parts of the three plants exhibited the highest significant values compared to the root parts. The MeOH extracts of Rumex species showed adequate antioxidant activity, wherein the IC50 values of the MeOH from the cultivated sample was 41.61 and 31.31 mg mL-1, coastal samples were 34.99 and 23.99 mg mL-1, while the sample of inland showed IC50 value of 41.59 and 31.67 mg mL-1, for root and shoot, respectively. Furthermore, using a filter paper disc assay, the MeOH extracts of the three Rumex species showed a substantial anti-microbial inhibitory effect on the growth of 10 pathogenic bacteria. According to sensitivity, the tested organisms could be sequenced as following: E. coli < K. pneumoniae ˂ S. typhi < P. aeruginosa for Gram-negative bacteria and B. subtilis < S. pneumoniae ˂ L. monocytoyenes < S. epidermis < S. aureus < B. cereus for Gram-positive bacteria. In addition, the antibacterial performance of R. dentatus root and R. vesicarius shoot MeOH extract is 100% broad spectrum against Gram-negative bacteria. A shoot of R. dentatus and R. pictus MeOH extract against Gram-positive bacteria is 83.3% broad spectrum. A further study is recommended for more characterization of the major compounds and assesses their efficiency and biosafety.

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

10.21203/rs.3.rs-1049725/v1 ◽

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.

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Broad Spectrum Anti-Quorum Sensing Activity of Tannin-Rich Crude Extracts of Indian Medicinal Plants

Scientifica ◽

10.1155/2016/5823013 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Varsha Shukla ◽

Zarine Bhathena

Keyword(s):

Quorum Sensing ◽

Medicinal Plants ◽

Broad Spectrum ◽

Gram Negative Bacteria ◽

High Concentration ◽

Gram Positive ◽

Gram Negative ◽

Medicinal Plant Extracts ◽

Wide Range ◽

Autoinducing Peptides

Quorum sensing (QS) mechanisms have been demonstrated to have significance in expression of pathogenicity in infectious bacteria. In Gram negative bacteria the autoinducer molecules that mediate QS are acyl homoserine lactones (AHL) and in Gram positive bacteria they are peptides called autoinducing peptides (AIP). A screening of tannin-rich medicinal plants was attempted to identify extracts that could interrupt the QS mechanisms in both Gram positive and Gram negative bacteria over a wide range of concentrations and therefore potentially be potent agents that could act as broad spectrum QS inhibitors. Six out of the twelve Indian medicinal plant extracts that were analyzed exhibited anti-QS activity inChromobacterium violaceum12472 and inS.aureusstrain withagr:blaZfusion over a broad range of subinhibitory concentrations, indicating that the extracts contain high concentration of molecules that can interfere with the QS mechanisms mediated by AHL as well as AIP.

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Quenching of acyl-homoserine lactone-dependent quorum sensing by enzymatic disruption of signal molecules.

Acta Biochimica Polonica ◽

10.18388/abp.2009_2512 ◽

2009 ◽

Vol 56 (1) ◽

Cited By ~ 112

Author(s):

Robert Czajkowski ◽

Sylwia Jafra

Keyword(s):

Quorum Sensing ◽

Pathogenic Bacteria ◽

Degradation Products ◽

Antibiotic Production ◽

Quorum Quenching ◽

Homoserine Lactone ◽

Signal Molecules ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Animal Pathogens

Many Gram-positive and Gram-negative bacteria communicate using small diffusible signal molecules called autoinducers. This process, known as quorum sensing (QS), links cell density to the expression of genes as diverse as those associated with virulence factors production of plant and animal pathogens, bioluminescence, antibiotic production, sporulation or biofilm formation. In Gram-negative bacteria, this communication is mainly mediated by N-acyl-homoserine lactones (AHLs). It has been proven that inactivation of the signal molecules attenuates many of the processes controlled by QS. Enzymatic degradation of the signal molecules has been amply described. Two main classes of AHL-inactivating enzymes were identified: AHL lactonases which hydrolyse the lactone ring in AHLs, and AHL acylases (syn. AHL amidases) which liberate a free homoserine lactone and a fatty acid. Recently, AHL oxidoreductase, a novel type of AHL inactivating enzyme, was described. The activity of these enzymes results in silencing the QS-regulated processes, as degradation products cannot act as signal molecules. The ability to inactivate AHL (quorum quenching, QQ) might be useful in controlling virulence of many pathogenic bacteria.

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Antibacterial activity of grapefruit peel extracts and green-synthesized silver nanoparticles

Veterinary World ◽

10.14202/vetworld.2021.1330-1341 ◽

2021 ◽

pp. 1330-1341

Author(s):

Mbarga M. J. Arsène ◽

I. V. Podoprigora ◽

Anyutoulou K. L. Davares ◽

Marouf Razan ◽

M. S. Das ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Inhibitory Concentration ◽

Antibacterial Properties ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria ◽

Grapefruit Peel ◽

Green Synthesized Silver Nanoparticles

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.

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Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽

10.1186/s13568-021-01213-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Susanna Gevorgyan ◽

Robin Schubert ◽

Mkrtich Yeranosyan ◽

Lilit Gabrielyan ◽

Armen Trchounian ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Green Synthesis ◽

Royal Jelly ◽

Fluorescence Emission ◽

Spherical Particles ◽

Ag Nps ◽

Gram Negative ◽

Green Synthesized Silver Nanoparticles ◽

Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

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Coumarin Exhibits Broad-Spectrum Antibiofilm and Antiquorum Sensing Activity against Gram-Negative Bacteria: In Vitro and In Silico Investigation

ACS Omega ◽

10.1021/acsomega.1c02046 ◽

2021 ◽

Author(s):

Faizan Abul Qais ◽

Mohammad Shavez Khan ◽

Iqbal Ahmad ◽

Fohad Mabood Husain ◽

Rais Ahmad Khan ◽

...

Keyword(s):

Broad Spectrum ◽

In Silico ◽

Gram Negative Bacteria ◽

Gram Negative

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Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

NeuroQuantology ◽

10.14704/nq.2021.19.9.nq21135 ◽

2021 ◽

Vol 19 (9) ◽

pp. 38-45

Author(s):

Hussein H. Al-Turnachy ◽

Fadhilk. alibraheemi ◽

Ahmed Abd Alreda Madhloom ◽

Zahraa Yosif Motaweq ◽

Nibras Yahya Abdulla

Keyword(s):

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Biological Activity ◽

Pathogenic Bacteria ◽

Punica Granatum ◽

Gram Positive ◽

Gram Negative ◽

Inhibition Zones ◽

Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

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Chemical probe of AHL modulators on quorum sensing in Gram-Negative Bacteria and as antiproliferative agents: A review

European Journal of Medicinal Chemistry ◽

10.1016/j.ejmech.2021.113864 ◽

2021 ◽

Vol 226 ◽

pp. 113864

Author(s):

Maxwell Ampomah-Wireko ◽

Chunying Luo ◽

Yaquan Cao ◽

Huanhuan Wang ◽

Lauraine Nininahazwe ◽

...

Keyword(s):

Quorum Sensing ◽

Gram Negative Bacteria ◽

Chemical Probe ◽

Antiproliferative Agents ◽

Gram Negative

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