scholarly journals Tunable plasmonic colorimetric assay with inverse sensitivity for extracellular DNA quantification

2018 ◽  
Vol 54 (80) ◽  
pp. 11260-11263 ◽  
Author(s):  
Roger M. Pallares ◽  
Nguyen T. K. Thanh ◽  
Xiaodi Su
Keyword(s):  
Colorimetric Assay ◽  
Dna Quantification ◽  
Extracellular Dna ◽  
Aqueous Environments

Extracellular DNA (eDNA) is a biomolecule commonly used to characterize microorganism communities in soil and aqueous environments.

scholarly journals Characterization of Enterococcus faecalis in different culture conditions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mi-Ah Kim ◽  
Vinicius Rosa ◽  
Kyung-San Min
Keyword(s):  
Enterococcus Faecalis ◽  
Laser Scanning ◽  
Colorimetric Assay ◽  
Culture Conditions ◽  
Laser Scanning Microscopy ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Qrt Pcr ◽  
Microscopy Analysis

AbstractThe aim of this study was to investigate how carbohydrates (glucose or sucrose) affect the characteristics of Enterococcus faecalis (E. faecalis) planktonic and biofilm in vitro. For this study, E. faecalis was cultured in tryptone-yeast extract broth with 0% glucose + 0% sucrose, 0.5% glucose, 1% glucose, 0.5% sucrose, or 1% sucrose. Viability of E. faecalis was examined by colony forming unit counting assays. Biofilm formation was assessed by measuring extracellular DNA (eDNA), a component of the biofilm matrix. Quantitative real-time PCR (qRT-PCR) was performed to investigate the expression of virulence-associated genes. Field emission scanning electron microscopy analysis, confocal laser scanning microscopy analysis, and crystal violet colorimetric assay were conducted to study E. faecalis biofilms. E. faecalis showed the highest viability and eDNA levels in 1% sucrose medium in biofilms. The result of qRT-PCR showed that the virulence-associated genes expressed highest in 1% sucrose-grown biofilms and in 1% glucose-grown planktonic cultures. E. faecalis showed highly aggregated biofilms and higher bacteria and exopolysaccharide (EPS) bio-volume in sucrose than in 0% glucose + 0% sucrose or glucose. The results indicate that the production of eDNA and EPS and expression of virulence-associated genes in E. faecalis are affected by the concentration of carbohydrates in biofilm or planktonic culture.

scholarly journals Antibiofilm Activity of Extract and a Compound Isolated from Triumfetta welwitschii against Pseudomonas aeruginosa

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Molly Mombeshora ◽  
Godloves Fru Chi ◽  
Stanley Mukanganyama
Keyword(s):  
Mass Spectrometry ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Column Chromatography ◽  
Dna Content ◽  
Capsular Polysaccharide ◽  
Colorimetric Assay ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Broth Microdilution Method

Triumfetta welwitschii has been used as a traditional medicine in Africa. It is documented as a rich source of phytochemicals with antibacterial activities. To further explore the antibacterial potential of these phytochemical components, the phytochemical profile of the dichloromethane: methanol leaf extract from T. welwitschii was investigated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Compounds were isolated from the extract using column chromatography and thin-layer chromatography. Compound B1 was isolated from the fraction eluted by 90 hexane:10 ethyl acetate using column chromatography. The antibacterial activity of B1 against Pseudomonas aeruginosa was evaluated in vitro using the broth microdilution method and the iodonitrotetrazolium (INT) colorimetric assay. The antibiofilm activities of the extract and B1 against P. aeruginosa were determined by quantifying the biofilms using crystal violet. The effect of the extract and B1 on capsular polysaccharide and extracellular DNA content of biofilm formed by P. aeruginosa was determined using phenol-sulphuric acid and propidium iodide, respectively. A total of 28 peaks were detected and identified using UPLC-MS/MS. The three most abundant phytochemicals identified were catechin, umbelliferone, and a luteolin derivative. B1 showed antibacterial activity against P. aeruginosa with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of 25 μg/ml. Only 38% and 6% of the biofilms were formed in the presence of the extract and B1, respectively. The extract and B1 reduced the capsular polysaccharide content in biofilms formed in P. aeruginosa by 40% and 65%, respectively. The extract and B1 significantly reduced the extracellular DNA content of biofilms by 29% and 72%, respectively. The results of this study provide evidence of the antibacterial and antibiofilm activities of B1 and leaf extracts from T. welwitschii. Future work should identify the chemical structure of B1 using nuclear magnetic resonance and mass spectrometry.

The Preparation of p(acrylonitrile-co-acrylamide) hydrogels for uranyl ion recovery from aqueous environments

2014 ◽  
Vol 1 (42) ◽  
pp. 89-89 ◽  
Author(s):  
Duygu Alpaslan ◽  
Nahit Aktas ◽  
Selehattin Yilmaz ◽  
Nurettin Sahiner
Keyword(s):  
Uranyl Ion ◽  
Aqueous Environments

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

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