scholarly journals Carbon Dots Modification for Escherichia coli Detection: Variation of Colistin Sulphate Concentration

2019 ◽  
Vol 35 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Suherman Suherman ◽  
Nicko Audio Haryanto ◽  
Endang Tri Wahyuni ◽  
Miftahul Ilmi ◽  
Kinichi Morita ◽  
...  

Escherichia coli (E. coli) bacteria widely recognize as a major treatment in water quality as diarrhea disease becoming one of leading causes of mortality worldwide. Carbon dots (CDs) modification study for detection of E. coli with the variation of colistin sulphate concentration has been conducted. The purpose of this research is to evaluate the effect of colistin sulphate concentration variation on fluorescence intensity for detecting E. coli bacteria in water samples. This study started by synthesizing CDs and CDs colistin variation concentrations of 1.0; 1.5; 2.0 and 2.5 mmol through carbonization of ammonium citrate and the addition of colistin. All precursors are characterized by using FT-IR. Morphological forms were evaluated with scanning emission microscopy (SEM) and transmission electron microscopy (TEM). CDs and CDs colistin solutions were measured their spectras with a UV-Vis spectrophotometer. Each of these CDs colistin was determined at the excitation wavelength ranges of 310-450 nm using a spectrofluorophotometer. Subsequently, CDs colistin was used for bacterial detection in samples with variation in E. coli bacteria concentration, thus analyzed by spectrofluorophotometer with an optimum excitation wavelength. The results showed that the highest intensity of fluorescence on CDs colistin occurred at the wavelength excitation of 360 nm. CDs colistin with the variation of colistin concentration 2.5 mmol revealed the highest fluorescence intensity. For the detection of E. coli, all CDs colistin produced the same trends of fluorescence spectra as the higher concentration of E. coli in the samples produced the higher intensity of emission.

2021 ◽  
Author(s):  
Amalanathan.M ◽  
Aravind.M ◽  
Sony Michael Mary.M ◽  
Razan A. Alshgari ◽  
Asma A. Alothman ◽  
...  

Abstract In this work, jasmine flower derived activated carbon were successfully synthesized by hydrothermal carbonization process at the different annealing temperature. The Crystallinity, phase, structural, morphological and optical properties of activated carbon were investigated using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscope (TEM), and UV-visible spectroscopy analysis. The graphitic phase of carbon was obtained from the XRD pattern. Surface morphology reveals irregular-shaped nanoparticles. The photodegradation of methylene blue (MB) was carried out under the visible light irradiation technique to study its photocatalytic activity. The activated carbon obtained at 400oC, 500oC and 600oC shows a photocatalytic degradation efficiency of 86%, 90%, and 94%, respectively. Antibacterial activity of activated carbon was examined against S. Aureus (MTCC-737) and E-Coli (MTCC- 443) microbial pathogens, and their potent antibacterial activity was examined from the zone of inhibition layer.


2016 ◽  
Vol 9 (2) ◽  
pp. 15
Author(s):  
Emil Salim ◽  
Hasnirwan ◽  
Sanusi Ibrahim ◽  
Afrizal

Kitooligosakarida-2,5-anhidro-D-mannofuranosa (KOSamf) dipersiapkan dengan derajat polimerisasi tertentu melalui reaksi nitrous deaminasi dari kitosan parsial N-deasetilasi. KOSamf kemudian diubah menjadi turunan KOSamf dengan mengkopling gugus aldehid yang terdapat pada unit 2,5-anhidro-D-mannofuranosa (amf). KOSamf dengan 3,5-dikloroanilin dan NaBH3CN dalam pelarut buffer ammonium asetat direaksikan melalui metoda one-pot aminasi reduktif untuk menghasilkan turunan KOSamf yang berpotensi sebagai senyawa antibakteri dan antijamur. Struktur kimia dari turunan KOSamf yang telah disintesis dikarakterisasi dengan Spektroskopi FT-IR dan NMR. Senyawa turunan KOSamf memiliki aktivitas sebagai antibakteri terhadap bakteri Staphylococcus aureus dengan zona inhibisi 12,5 mm dan bakteri E. coli dengan zona inhibisi 10,5 mm.


2014 ◽  
Vol 59 (No. 8) ◽  
pp. 374-380
Author(s):  
E. Skřivanová ◽  
Š. Pražáková ◽  
O. Benada ◽  
P. Hovorková ◽  
MarounekM

The sucrose monoesters of capric and lauric acid were tested for their antibacterial activity towards two foodborne enteropathogenic bacteria &ndash; Escherichia coli (CCM 3954 &ndash; serotype O6 and E22 &ndash; serotype O103) and Clostridium perfringens (CNCTC 5459 and CIP 105178). Antibacterial activity was evaluated by the plating technique. Sucrose monocaprate significantly decreased the number of viable cells of E. coli at all tested concentrations (0.1&ndash;5 mg/ml). The overnight incubation of C. perfringens with the sucrose ester of lauric acid at 0.1&ndash;5 mg/ml reduced the number of viable cells below the detection limit (2 log<sub>10</sub> CFU/ml). Incubating E. coli CCM 3954 and C. perfringens CNCTC 5459 with monoesters (0.1 and 2 mg/ml) did not influence the K<sup>+</sup> permeability of the cytoplasmic membrane in cells during a 2.5-minute treatment. A 30-minute incubation of E. coli CCM 3954 and C. perfringens CNCTC 5459 with esters (0.1 and 2 mg/ml) revealed damage to cytoplasmic structures, as observed by transmission electron microscopy. &nbsp;


2020 ◽  
Vol 21 (22) ◽  
pp. 8654
Author(s):  
Yanath Belguesmia ◽  
Noura Hazime ◽  
Isabelle Kempf ◽  
Rabah Boukherroub ◽  
Djamel Drider

Lacticaseibacillus paracasei CNCM I-5369, formerly Lactobacillus paracasei CNCM I-5369, produces bacteriocins that are remarkably active against Gram-negative bacteria, among which is the Escherichia coli-carrying mcr-1 gene that is involved in resistance to colistin. These bacteriocins present in the culture supernatant of the producing strain were extracted and semi-purified. The fraction containing these active bacteriocins was designated as E20. Further, E20 was loaded onto alginate nanoparticles (Alg NPs), leading to a highly active nano-antibiotics formulation named hereafter Alg NPs/E20. The amount of E20 adsorbed on the alginate nanoparticles was 12 wt.%, according to high-performance liquid chromatography (HPLC) analysis. The minimal inhibitory concentration (MIC) values obtained with E20 ranged from 250 to 2000 μg/mL, whilst those recorded for Alg NPs/E20 were comprised between 2 and 4 μg/mL, which allowed them to gain up to 500-fold in the anti-E. coli activity. The damages caused by E20 and/or Alg NPs/E20 on the cytology of the target bacteria were characterized by transmission electron microscopy (TEM) imaging and the quantification of intracellular proteins released following treatment of the target bacteria with these antimicrobials. Thus, loading these bacteriocins on Alg NPs appeared to improve their activity, and the resulting nano-antibiotics stand as a promising drug delivery system.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xinzhu Huo ◽  
Yuxuan He ◽  
Shiqi Ma ◽  
Yingying Jia ◽  
Jiaming Yu ◽  
...  

In this study, undoped carbon quantum dots (UCQDs, UCQDs-peel) and N-doped carbon dots (NCQDs) were prepared by a facile one-pot environmentally friendly hydrothermal method using grapefruit as carbon sources in the absence and presence of area, respectively. The structure, morphology, and fluorescence properties of three samples were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and photoluminescence (PL). It was found that three types of CQDs could emit blue fluorescence with different intensities when irradiated with ultraviolet light. Compared to the luminescence properties of UCQDs, NCQDs, and UCQDs-peel, it can be seen that the fluorescence intensity of NCQDs was strongest due to the presence of NH and C-N bonds.


Molbank ◽  
10.3390/m1058 ◽  
2019 ◽  
Vol 2019 (2) ◽  
pp. M1058
Author(s):  
Vinuta Kamat ◽  
Rangappa Santosh ◽  
Suresh Nayak

5-methyl-2-(pyridin-3-yl)-1,3-thiazole-4-carbohydrazide (1) on treatment with 4-fluorobenzaldehyde in presence of catalytic amount of acetic acid, accessed the target compound (2) with the yield of 79%. The target compound was confirmed by 1H-NMR, 13C-NMR, FT-IR and LCMS. In vitro antibacterial activity against Staphylococcus aureus (S. Aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) were carried out and compound 2 showed promising activity against B. subtilis. In addition, compound 2 was analyzed for DNA binding study. It revealed that compound 2 has a promising affinity towards DNA double helix.


2020 ◽  
Vol 21 (2) ◽  
pp. 106-113
Author(s):  
D.K. Adeyemi ◽  
A.O. Adeluola ◽  
M.J. Akinbile ◽  
O.O. Johnson ◽  
G.A. Ayoola

Background: Nanotechnology offers an advantage as a green route for synthesis of metal nanoparticles (NPs) with plant extracts as capping agent. Spondias mombin is a fruit-bearing tree and its leaf extracts have been reported to possess anxiolytic, hypoglycaemic, antiepileptic, antipsychotic, sedative, antioxidant, and antimicrobial properties. The objective of the study is to determine the antibacterial potential of a simple non-toxic product of green synthesis of metallic (Ag, Zn and Cu) nanoparticles using the leaf of Spondias mombin aqueous extracts (SMAE) as a reducing and capping agents of the metal ions.Methodology: Nanoparticles were characterized by UV visible spectrophotometeric analysis, Fourier Transform Infra-Red (FT-IR) spectrophotometer and scanning electron microscope (SEM). Antimicrobial activities of synthesized NPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were determined by agar well diffusion technique.Results: The synthesized NPs varied in colour from dark brown to green and appears dominantly spherical, occasionally rod or triangular shaped with size ranging from 65-90 nm. UV spectroscopy absorption spectra of Ag, Zn and Cu NPs had absorbance peak at 267, 262 and 765 nm respectively. FT-IR spectrometry of Zn NP, Cu NP, and SMAE gave wave number ranging from 895.71-3320.67, 747.02-3225.45 and 658.25-3674.49 respectively. FT-IR analysis showed that SMAE acted as reducing and stabilizing agent while the NPs exhibited lower energy absorption band when compared to the plant extract. The NPs demonstrated higher antimicrobial activities against S. aureus than Ps. aeruginosa and E. coli. The antimicrobial activity was higher with copper NP than Ag and Zn NPs, and also higher than SMAE.Conclusion: The result from this study presents an indication for an alternative means for development of novel antimicrobial agents for clinical and biotechnological applications.Keywords: synthesis, nanoparticles, FT-IR, UV-visible spectrophotometry, antibacterial activitiesFrench Title: Synthèse verte de nanoparticules d'Ag, de Zn et de Cu à partir d'extrait aqueux de feuilles de Spondias mombin et évaluation de leur activité antibactérienneContexte: La nanotechnologie offre un avantage en tant que voie verte pour la synthèse de nanoparticules métalliques (NP) avec des extraits de plantes comme agent de coiffage. Spondias mombin est un arbre fruitier et ses extraits de feuilles possèdent des propriétés anxiolytiques,  hypoglycémiques, antiépileptiques, antipsychotiques, sédatives,  antioxydantes et antimicrobiennes. L’objectif de l’étude est de déterminer le potentiel antibactérien d’un simple produit non toxique de synthèse verte de nanoparticules métalliques (Ag, Zn et Cu) à l’aide de la feuille d’extraits aqueux de Spondias mombin (SMAE) en tant qu’agent réducteur et coiffant de la ions métalliques.Méthodologie: Les nanoparticules ont été caractérisées par analyse  spectrophotométrique UV visible, spectrophotomètre à transformée de Fourier infrarouge (FT-IR) et microscope électronique à balayage (MEB). Lesactivités antimicrobiennes de NP synthétisées contre Escherichia coli, Staphylococcus aureus et Pseudomonas aeruginosa ont été déterminées par une technique de diffusion sur puits d’agar.Résultats: Les NP synthétisés ont une couleur allant du brun foncé au vert et apparaissent principalement sphériques, parfois en bâtonnets ou en triangles, avec des tailles allant de 65 à 90 nm. Les spectres  d'absorption par spectroscopie UV des NP Ag, Zn et Cu présentaient des pics  d'absorbance à 267, 262 et 765 nm respectivement. La spectrométrie FT-IR de Zn NP, Cu NP et SMAE a donné un nombre d'onde allant de 895,71 à 3320,67, 747,02 à 3225,45 et 658,25 à 3674,49 respectivement. L'analyse FT-IR a montré que le SMAE agissait en tant qu'agent réducteur et  stabilisant, alors que les NP présentaient une bande d'absorption d'énergie inférieure à celle de l'extrait de plante. Les NP ont démontré des activités antimicrobiennes plus élevées contre S. aureus que Ps. aeruginosa et E. coli. L'activité antimicrobienne était plus élevée avec les NP en cuivre que dans les NP Ag et Zn, et également supérieure à celle du SMAE.Conclusion: le résultat de cette étude présente une indication d'un autre moyen de développement de nouveaux agents antimicrobiens pour des applications cliniques et biotechnologiques.Mots-clés: synthèse, nanoparticules, FT-IR, spectrophotométrie UV-visible, activités antibactériennes 


Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 454 ◽  
Author(s):  
Imke H. E. Korf ◽  
Jan P. Meier-Kolthoff ◽  
Evelien M. Adriaenssens ◽  
Andrew M. Kropinski ◽  
Manfred Nimtz ◽  
...  

The aim of this study was to gain further insight into the diversity of Escherichia coli phages followed by enhanced work on taxonomic issues in that field. Therefore, we present the genomic characterization and taxonomic classification of 50 bacteriophages against E. coli isolated from various sources, such as manure or sewage. All phages were examined for their host range on a set of different E. coli strains, originating, e.g., from human diagnostic laboratories or poultry farms. Transmission electron microscopy revealed a diversity of morphotypes (70% Myo-, 22% Sipho-, and 8% Podoviruses), and genome sequencing resulted in genomes sizes from ~44 to ~370 kb. Annotation and comparison with databases showed similarities in particular to T4- and T5-like phages, but also to less-known groups. Though various phages against E. coli are already described in literature and databases, we still isolated phages that showed no or only few similarities to other phages, namely phages Goslar, PTXU04, and KWBSE43-6. Genome-based phylogeny and classification of the newly isolated phages using VICTOR resulted in the proposal of new genera and led to an enhanced taxonomic classification of E. coli phages.


2020 ◽  
Vol 10 (11) ◽  
pp. 1777-1787
Author(s):  
Yadian Xie ◽  
Shanshan Wang ◽  
Ning Fu ◽  
Yan Yang ◽  
Xingliang Liu ◽  
...  

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.


2016 ◽  
Vol 55 (2) ◽  
pp. 81-90 ◽  
Author(s):  
M.A. Prieto-Calvo ◽  
M.K. Omer ◽  
O. Alvseike ◽  
M. López ◽  
A. Alvarez-Ordóñez ◽  
...  

AbstractPhenotypic, chemotaxonomic and genotypic data from 12 strains ofEscherichia coli werecollected, including carbon source utilisation profiles, ribotypes, sequencing data of the 16S–23S rRNA internal transcribed region (ITS) and Fourier transform-infrared (FT-IR) spectroscopic profiles. The objectives were to compare several identification systems forE. coliand to develop and test a polyphasic taxonomic approach using the four methodologies combined for the sub-typing of O157 and non-O157E. coli. The nucleotide sequences of the 16S–23S rRNA ITS regions were amplified by polymerase chain reaction (PCR), sequenced and compared with reference data available at the GenBank database using the Basic Local Alignment Search Tool (BLAST) . Additional information comprising the utilisation of carbon sources, riboprint profiles and FT-IR spectra was also collected. The capacity of the methods for the identification and typing ofE. colito species and subspecies levels was evaluated. Data were transformed and integrated to present polyphasic hierarchical clusters and relationships. The study reports the use of an integrated scheme comprising phenotypic, chemotaxonomic and genotypic information (carbon source profile, sequencing of the 16S–23S rRNA ITS, ribotyping and FT-IR spectroscopy) for a more precise characterisation and identification ofE. coli. The results showed that identification ofE. colistrains by each individual method was limited mainly by the extension and quality of reference databases. On the contrary, the polyphasic approach, whereby heterogeneous taxonomic data were combined and weighted, improved the identification results, gave more consistency to the final clustering and provided additional information on the taxonomic structure and phenotypic behaviour of strains, as shown by the close clustering of strains with similar stress resistance patterns.


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