scholarly journals Using an environmentally-relevant panel of Gram-negative bacteria to assess the toxicity of polyallylamine hydrochloride-wrapped gold nanoparticles

2018 ◽  
Vol 5 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Joseph T. Buchman ◽  
Ali Rahnamoun ◽  
Kaitlin M. Landy ◽  
Xi Zhang ◽  
Ariane M. Vartanian ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Diversity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Polyallylamine Hydrochloride

We aim to establish the effect of bacterial diversity in assessing nanotoxicity.

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

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.

Biogenic Gold Nanoparticles and its Antibacterial Activities: Houttuynia Cordata Leaf Extract

2014 ◽  
Vol 1051 ◽  
pp. 392-397
Author(s):  
T.V.M. Sreekanth ◽  
In Yong Eom
Keyword(s):  
Gold Nanoparticles ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Houttuynia Cordata ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Visible Spectra ◽  
Uv Visible

Gold nanoparticles (AuNPs) can be prepared in a number of chemical techniques, which are not environmentally friendly. Biosynthesis of nanoparticles by plant extracts is currently under exploitation. In this work, we describe an eco-friendly technique for green synthesis of AuNPs from AuCl4 solution using the Houttuynia cordata leaf extract as reducing agent. The AuNPs were characterized using UV-Visible spectroscopy, SEM, TEM, FTIR and AFM. The UV-Visible spectra indicate a strong plasma resonance that is located at 535 nm. The antibacterial activity of AuNPs was performed on various gram positive and gram negative bacteria. The AuNPs showed more inhibitory activity on gram negative than gram positive bacteria.

Gold nanoparticles as colorimetric sensor: A case study on E. coli O157:H7 as a model for Gram-negative bacteria

2012 ◽  
Vol 161 (1) ◽  
pp. 298-303 ◽  
Author(s):  
Haichao Su ◽  
Qiang Ma ◽  
Kun Shang ◽  
Tao Liu ◽  
Huanshun Yin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Colorimetric Sensor ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli

Evaluation of the Antibacterial Activity of Ag- and Au-Nanoparticles Loaded TiO2 Nanotubes

2020 ◽  
Vol 16 (9) ◽  
pp. 1416-1425
Author(s):  
Katarzyna Arkusz ◽  
Ewa Paradowska ◽  
Marta Nycz ◽  
Justyna Mazurek-Popczyk ◽  
Katarzyna Baldy-Chudzik
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Live Bacteria

Current research on the antibacterial properties of implant surfaces has focused on using titanium nanotubes (TNTs) with diameters of 100 and 200 nm, which simultaneously show the best antibacterial properties, poor osseointegration, and ability to immobilize proteins. Therefore, the research aimed to develop an implantable material based on titanium dioxide nanotubes with a diameter of 50 nm doped with silver (AgNPs) and gold nanoparticles (AuNPs), indicating good absorption and antibacterial properties. Moreover, metallic nanoparticles deposited by varying methods should maintain sphericity and lack of agglomeration. For this purpose, the surface charge, wettability, stability of nanoparticles, and antibacterial properties against Gram-positive and Gram-negative bacteria, i. e., Staphylococcus epidermidis, Streptococcus mutans, and Pseudomonas aeruginosa , were performed. Obtained results indicate a greater resistance to leaching of silver nanoparticles compared to gold nanoparticles. These results are reflected in microbiological studies, both into the time and the effectiveness of the implantable material's antibacterial activity. A greater antibacterial effect of AgNPs than AuNPs has been confirmed. Also, AgNPs inhibit the multiplication of Gram-negative bacteria to a greater extent than Gram-positive bacteria. It has been proven that the TNT platforms deposited with metal nanoparticles via the voltammetric method are more effective in deactivating microorganisms. Besides, the results have proven that smaller TNTs effectively reduce live bacteria as nanotubes with a diameter of 100 and 200 nm.

scholarly journals Bacterial diversity of chronic middle ear lesions revealed by high-throughput sequencing

2021 ◽  
Author(s):  
Xingzhi Gu ◽  
Xiuqing Cheng ◽  
Tuoheti Abulajiang ◽  
Xiaoban Huang
Keyword(s):  
Bacterial Diversity ◽  
Otitis Media ◽  
Middle Ear ◽  
Chronic Otitis Media ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Epithelial Tissue ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Middle Ear Cholesteatoma

AbstractChronic otitis media is a common middle ear disease in otolaryngology and head and neck surgery. Bacterial infection is considered the main cause of disease, but relying on conventional bacterial cultures can be problematic for identification of specific pathogens. Current research suggests that bacteria in microbial communities can only be identified by rDNA sequencing of bacteria.This prospective study utilized broad-range PCR amplification of 16S rRNA genes with clone analysis to compare bacterial diversity in lesions from 6 patients with chronic suppurative otitis media (CSOM) and 10 patients with cholesteatoma of middle ear lesions. Bacteria were analyzed at the phylum, order, family, genus, and species levels. Bacterial species abundance and species diversity were greater in cholesteatoma of the middle ear lesions than in CSOM lesions. At all bacterial taxonomic levels, the epithelial tissue of middle ear cholesteatoma was complex in terms of bacterial diversity, covering a large number of Gram-positive and Gram-negative bacteria, likely related to bacterial microbiome formation. In contrast, bacteriology of the CSOM lesions was relatively simple at all taxonomic levels, with all sequences characterized as belonging to Gram-negative bacteria. These results suggest that persistent infection of middle ear cholesteatoma may be a microbial flora disorder, which is related to conditional pathogenic bacteria, rather than a single bacterial infectious disease. Findings from the study may have implications in the selection of antimicrobial agents for the treatment of chronic otitis media.

scholarly journals Flavonoid-Coated Gold Nanoparticles as Efficient Antibiotics against Gram-Negative Bacteria—Evidence from In Silico-Supported In Vitro Studies

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 968
Author(s):  
Hani A. Alhadrami ◽  
Raha Orfali ◽  
Ahmed A. Hamed ◽  
Mohammed M Ghoneim ◽  
Hossam M. Hassan ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
In Silico ◽  
Biological Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Ic50 Values ◽  
Membrane Rigidity ◽  
Further Development

Flavonoids are a class of bioactive plant-derived natural products that exhibit a broad range of biological activities, including antibacterial ones. Their inhibitory activity toward Gram-positive bacterial was found to be superior to that against Gram-negative ones. In the present study, a number of flavonoid-coated gold nanoparticles (GNPs) were designed to enhance the antibacterial effects of chrysin, kaempferol, and quercetin against a number of Gram-negative bacteria. The prepared GNPs were able to conjugate to these three flavonoids with conjugation efficiency ranging from 41% to 80%. Additionally, they were able to exert an enhanced antibacterial activity in comparison with the free flavonoids and the unconjugated GNPs. Quercetin-coated GNPs were the most active nano-conjugates and were able to penetrate the cell wall of E. coli. A number of in silico experiments were carried out to explain the conjugation efficiency and the antibacterial mechanisms of these flavonoids as follows: (i) these flavonoids can efficiently bind to the glutathione linker on the surface of GNPs via H-bonding; (ii) these flavonoids, particularly quercetin, were able to increase the bacterial membrane rigidity, and hence decrease its functionality; (iii) these flavonoids can inhibit E. coli’s DNA gyrase (Gyr-B) with IC50 values ranging from 0.9 to 3.9 µM. In conclusion, these bioactive flavonoid-based GNPs are considered to be very promising antibiotic candidates for further development and evaluation.

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
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