Small Molecule-Capped Gold Nanoparticles as Potent Antibacterial Agents That Target Gram-Negative Bacteria

2010 ◽  
Vol 132 (35) ◽  
pp. 12349-12356 ◽  
Author(s):  
Yuyun Zhao ◽  
Yue Tian ◽  
Yan Cui ◽  
Wenwen Liu ◽  
Wanshun Ma ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Small Molecule ◽  
Antibacterial Agents ◽  
Gram Negative Bacteria ◽  
Gram Negative

Facile and Novel Synthesis of Spiky Gold Nanoparticles as an Efficient Antimicrobial Agent against Pseudomonas Aeruginosa

2021 ◽  
Vol 24 ◽  
Author(s):  
Farooq Aziz ◽  
Muhammad Rashid ◽  
Mubashar Rehman ◽  
Muhammad Rafique ◽  
Muhammad Imran
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Agents ◽  
Reduction Method ◽  
Surface Plasmon Resonance Peak ◽  
Gram Negative Bacteria ◽  
Plasmon Resonance Peak ◽  
Gram Negative ◽  
Novel Synthesis

Aims: The study aims to develop advanced antibacterial agents as nanoparticles instead of antibiotics due to the emergence of antimicrobial resistance. Background: Pseudomonas aeruginosa is capable of causing many diseases, including severe bacterial pneumonia. There is a need for an efficient antibacterial agent to kill these pathogens. Objective: The objective of the study is to synthesize advanced antibacterial agents as nanoparticles for biomedical applications that can play a vital role in killing Gram-negative bacteria (Pseudomonas aeruginosa). Method: A novel fabricated growth of hydrophilic spiky gold nanoparticles (SGNPs) via reduction method is reported. Results: The surface plasmon resonance peak of the synthesized SGNPs was tuned under the near-infrared range. The SGNPs have anisotropic and spiky morphology with 68 nm size and -58 mV surface charge. They are pure, possessing adsorption similar to the organic material. Pseudomonas aeruginosa treated with synthesized SGNPs showed 60% bacterial death at the concentration of 100 μM. Conclusion: This work consists of the novel synthesis of SGNPs via a safe and simple reduction method. The synthesized SGNPs exhibit strong antibacterial activity against the Gram-negative bacteria Pseudomonas aeruginosa measured using a microplate assay test. The result showed that these SGNPs are ideal for biomedical applications.

Composites of Bacterial Cellulose and Small Molecule-Decorated Gold Nanoparticles for Treating Gram-Negative Bacteria-Infected Wounds

Small ◽  
2017 ◽  
Vol 13 (27) ◽  
pp. 1700130 ◽  
Author(s):  
Ying Li ◽  
Yue Tian ◽  
Wenshu Zheng ◽  
Yan Feng ◽  
Rong Huang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Cellulose ◽  
Small Molecule ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Infected Wounds

scholarly journals Apomorphine Targets the Pleiotropic Bacterial Regulator Hfq

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 257
Author(s):  
Florian Turbant ◽  
David Partouche ◽  
Omar El Hamoui ◽  
Sylvain Trépout ◽  
Théa Legoubey ◽  
...  
Keyword(s):  
Small Rnas ◽  
Antibacterial Agents ◽  
Amyloid Fibrils ◽  
Noncoding Rnas ◽  
Amyloid Formation ◽  
Gram Negative Bacteria ◽  
Translation Efficiency ◽  
Gram Negative ◽  
Bacterial Adaptation ◽  
E Coli

Hfq is a bacterial regulator with key roles in gene expression. The protein notably regulates translation efficiency and RNA decay in Gram-negative bacteria, thanks to its binding to small regulatory noncoding RNAs. This property is of primary importance for bacterial adaptation and survival in hosts. Small RNAs and Hfq are, for instance, involved in the response to antibiotics. Previous work has shown that the E. coli Hfq C-terminal region (Hfq-CTR) self-assembles into an amyloid structure. It was also demonstrated that the green tea compound EpiGallo Catechin Gallate (EGCG) binds to Hfq-CTR amyloid fibrils and remodels them into nonamyloid structures. Thus, compounds that target the amyloid region of Hfq may be used as antibacterial agents. Here, we show that another compound that inhibits amyloid formation, apomorphine, may also serve as a new antibacterial. Our results provide an alternative in order to repurpose apomorphine, commonly used in the treatment of Parkinson’s disease, as an antibiotic to block bacterial adaptation to treat infections.

scholarly journals A small-molecule inhibitor of BamA impervious to efflux and the outer membrane permeability barrier

2019 ◽  
Vol 116 (43) ◽  
pp. 21748-21757 ◽  
Author(s):  
Elizabeth M. Hart ◽  
Angela M. Mitchell ◽  
Anna Konovalova ◽  
Marcin Grabowicz ◽  
Jessica Sheng ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Small Molecule ◽  
Cytoplasmic Membrane ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bam Complex ◽  
Induced Aggregation

The development of new antimicrobial drugs is a priority to combat the increasing spread of multidrug-resistant bacteria. This development is especially problematic in gram-negative bacteria due to the outer membrane (OM) permeability barrier and multidrug efflux pumps. Therefore, we screened for compounds that target essential, nonredundant, surface-exposed processes in gram-negative bacteria. We identified a compound, MRL-494, that inhibits assembly of OM proteins (OMPs) by the β-barrel assembly machine (BAM complex). The BAM complex contains one essential surface-exposed protein, BamA. We constructed a bamA mutagenesis library, screened for resistance to MRL-494, and identified the mutation bamAE470K. BamAE470K restores OMP biogenesis in the presence of MRL-494. The mutant protein has both altered conformation and activity, suggesting it could either inhibit MRL-494 binding or allow BamA to function in the presence of MRL-494. By cellular thermal shift assay (CETSA), we determined that MRL-494 stabilizes BamA and BamAE470K from thermally induced aggregation, indicating direct or proximal binding to both BamA and BamAE470K. Thus, it is the altered activity of BamAE470K responsible for resistance to MRL-494. Strikingly, MRL-494 possesses a second mechanism of action that kills gram-positive organisms. In microbes lacking an OM, MRL-494 lethally disrupts the cytoplasmic membrane. We suggest that the compound cannot disrupt the cytoplasmic membrane of gram-negative bacteria because it cannot penetrate the OM. Instead, MRL-494 inhibits OMP biogenesis from outside the OM by targeting BamA. The identification of a small molecule that inhibits OMP biogenesis at the cell surface represents a distinct class of antibacterial agents.

Gold Nanoparticles as Dual Functional Sensor to DetectE.coliDH5αas a Model for Gram-negative Bacteria

2015 ◽  
Vol 62 (6) ◽  
pp. 521-527 ◽  
Author(s):  
Qun Ma ◽  
Nianchun Gong ◽  
Yanle Li ◽  
Xi Jiang ◽  
Li Yin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Dual Functional

scholarly journals Improving Antibacterial and Anti-biofilmic properties of urological catheters with Eucalyptus, Rosemary, Green tea and Ziziphora extracts by impregnation method

2021 ◽  
Author(s):  
Najme Akhlaghi-Ardekani ◽  
Davod Mohebbi-Kalhori ◽  
Abdolreza samimi ◽  
Reza Karazhyan
Keyword(s):  
Green Tea ◽  
Biofilm Formation ◽  
Antibacterial Agents ◽  
Antibacterial Properties ◽  
Polymer Materials ◽  
Gram Negative Bacteria ◽  
Impregnation Method ◽  
Herbal Extracts ◽  
Urinary Catheters ◽  
Gram Negative

Abstract The main complications of urinary catheters are the bacteria's biofilm formation and the urinary tract infection caused by gram-positive and gram-negative bacteria. In the recent years, the attention has changed its direction toward the antimicrobial, anti-biofilmic, and hydrophobicity effects of herbal extracts. Some of these extracts can inhibit the colonization of the two bacteria Staphylococcus aureus and Escherichia coli which are resistant to antibiotics. These bacteria can stick to the surface of polymer materials due to their hydrophobicity. Thus, antibacterial hydrophilic herbal extracts are supposed to help reduce the risk of the surficial infection if they are used to impregnate the urinary catheters. In this research, the extracts of these four plants eucalyptus, rosemary, green tea and ziziphora were used as the antibacterial agents. After the impregnation and modification of the sample catheters, they were tested by AFM, FE-SEM, ATR-FTIR methods to measure their mechanical, chemical, and hydrophilic properties, during the 21-day experiment period, compared to non-impregnated ones. The tests showed the silicone catheters impregnated by the herbal extracts have some significant anti-biofilmic and antibacterial properties (P˂0.0001) due to the increase in their hydrophilic property. The impregnated catheters could be release the extracts and killed bacteria in 21 days Therefore; some herbal extracts can be good alternatives to chemical drugs.

scholarly journals The Hitchhiker’s Guide to the Periplasm: Unexpected Molecular Interactions of Antibiotics Revealed by Considering Crowding Effects in E. coli

2020 ◽  
Author(s):  
Conrado Pedebos ◽  
Iain P. S. Smith ◽  
Alister Boags ◽  
Syma Khalid
Keyword(s):  
Molecular Dynamics ◽  
Antibacterial Agents ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Crowding Effects ◽  
Therapeutic Mechanism ◽  
Target Membrane ◽  
Dynamics Simulations ◽  
Crowded Environment

AbstractThe periplasm of Gram-negative bacteria is a highly crowded environment comprised of many different molecular species. Antibacterial agents that causes lysis of Gram-negative bacteria by their action against the inner membrane must cross the periplasm to arrive at their target membrane. Very little is currently known about their route through the periplasm, and the interactions they experience. To this end, here atomistic molecular dynamics simulations are used to study the path taken by the antibiotic polymyxin B1 through a number of models of the periplasm which are crowded with proteins and osmolytes to different extents. The simulations reveal that PMB1 forms transient and long-lived interactions with proteins and osmolytes that are free in solution as well as lipoproteins anchored to the outer membrane and bound to the cell wall. We show that PMB1 may be able to ‘hitchhike’ within the periplasm by binding to lipoprotein carriers. Overall our results show that PMB1 is rarely uncomplexed within the periplasm; an important consideration for interpretations of its therapeutic mechanism of action. It is likely that this observation can be extended to other antibiotics that rely on diffusion to cross the periplasm.

scholarly journals Sensitivity Pattern of Gram Negative Bacteria Contaminating Traumatic Wounds: A Retrospective Study in a Tertiary Care Hospital of Kathamandu Valley

2020 ◽  
Vol 19 (2) ◽  
pp. 103-107
Author(s):  
Satya Narayan Suwal ◽  
Sammodavardhana Kaundinnyayana ◽  
Krishna Govinda Prajapati ◽  
Reena Baidya
Keyword(s):  
Retrospective Study ◽  
Antibacterial Agents ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Gram Negative ◽  
Accidental Trauma ◽  
Culture Positivity ◽  
Sensitivity Pattern ◽  
Culture Positivity Rate

Introduction: Gram negative bacteria are commonly involved in wound infections and are significantly associated with morbidity and mortality because of increasing resistance to commonly used antibacterial agents. This study aims to evaluate the pattern of antibacterial sensitivity of the gram negative bacteria from wound swabs of accidental trauma cases. Methods: This retrospective study was done by collecting all the culture positive reports for wound swabs of accidental wounds from the microbiology laboratory and analyzing the reports showing growth of gram negative bacteria for frequency of sensitivity to commonly used antibacterial agents. Results: Culture positivity rate was 21.95% with growth of gram negative bacteria in 79.7% of cases. The most commonly isolated organism was Escherichia coli being 41.3% among gram negative isolates. Highly resistant bacteria were E. coli, Klebsiella pneumoniae and Acinetobacter spp. Conclusions: As there is low culture positivity rate for wound swabs obtained before washing the wounds inflicted by accidental trauma, prolonged routine use of prophylactic antibiotic is not justified. Thoroughly washing the wound is very likely to decrease the rate of wound infection further and reduces the need of antibacterial agents. Culture and sensitivity test should guide the treatment when wound is infected because highly resistant gram negative organism may be involved in such cases.

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