scholarly journals Detection of Escherichia coli bacteria by impact electrochemistry

The Analyst ◽  
2018 ◽  
Vol 143 (20) ◽  
pp. 4840-4843 ◽  
Author(s):  
Rosa A. S. Couto ◽  
Lifu Chen ◽  
Sabine Kuss ◽  
Richard G. Compton
Keyword(s):  
Escherichia Coli ◽  
Label Free ◽  
Redox Species ◽  
E Coli ◽  
Label Free Detection ◽  
Escherichia Coli Bacteria ◽  
First Time ◽  
Phenylene Diamine

Employing the redox species N,N,N′,N′-tetramethyl-para-phenylene-diamine (TMPD), the label-free detection of E. coli, based on an electrochemical “on”-signal during impact electrochemistry, is reported for the first time.

Size-dependent optical extinction of MoS2 nanosheets and their aptamer-induced dispersion behavior for the label-free detection of Escherichia coli O157:H7

The Analyst ◽  
2021 ◽  
Author(s):  
Jiye Li ◽  
Jie Wang
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Label Free ◽  
Mos2 Nanosheets ◽  
Optical Extinction ◽  
Size Dependent ◽  
Dispersion Behavior ◽  
Label Free Detection ◽  
First Time

For the first time, we have revealed the size-dependent extinction response of MoS2-NS aggregation, the phenomenon of which has been employed as a sensing strategy for the label-free detection of Escherichia coli O157:H7.

Label-free detection of Escherichia coli bacteria by cascaded chirped long period gratings immunosensor

2019 ◽  
Vol 90 (2) ◽  
pp. 025003 ◽  
Author(s):  
Siddharth Kaushik ◽  
Umesh Tiwari ◽  
Nilima ◽  
Shivendu Prashar ◽  
Bhargab Das ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Label Free ◽  
Long Period ◽  
Long Period Gratings ◽  
Label Free Detection ◽  
Escherichia Coli Bacteria

scholarly journals Rapid label-free detection of E. coli using antimicrobial peptide assisted impedance spectroscopy

2015 ◽  
Vol 7 (23) ◽  
pp. 9744-9748 ◽  
Author(s):  
Keren Jiang ◽  
Hashem Etayash ◽  
Sarfuddin Azmi ◽  
Selvaraj Naicker ◽  
Mahtab Hassanpourfard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Impedance Spectroscopy ◽  
Antimicrobial Peptide ◽  
Rapid Detection ◽  
Sensor Array ◽  
Label Free ◽  
E Coli ◽  
Sensor Platform ◽  
Label Free Detection

A compact, label-free sensor array for rapid detection ofEscherichia coli(E. coli) using antimicrobial peptide assisted impedimetric sensor platform.

scholarly journals Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huiyi Song ◽  
Ni Lou ◽  
Jianjun Liu ◽  
Hong Xiang ◽  
Dong Shang
Keyword(s):  
Escherichia Coli ◽  
Proteomic Analysis ◽  
Biofilm Formation ◽  
Lactobacillus Rhamnosus ◽  
Differentially Expressed ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Quantitative Proteomic Analysis ◽  
E Coli ◽  
Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

Label-Free Detection of Escherichia coli from Mixed Bacterial Cultures Using Bacteriophage T4 on Plasmonic Fiber-Optic Sensor

ACS Sensors ◽  
2021 ◽  
Author(s):  
Pallavi Halkare ◽  
Nirmal Punjabi ◽  
Jigme Wangchuk ◽  
Santhosh Madugula ◽  
Kiran Kondabagil ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fiber Optic ◽  
Bacteriophage T4 ◽  
Fiber Optic Sensor ◽  
Label Free ◽  
Bacterial Cultures ◽  
Optic Sensor ◽  
Label Free Detection

scholarly journals GREEN SYNTHESIS OF MAGNETIC IRON NANOPARTICLES USING MEDICINAL PLANT TRIDAX PROCUMBENS LEAF EXTRACTS AND ITS APPLICATION AS AN ANTIMICROBIAL AGENT AGAINST E. COLI

2020 ◽  
pp. 34-39
Author(s):  
YOJANA Y. PATIL ◽  
VAISHNVI B. SUTAR ◽  
ARPITA P. TIWARI
Keyword(s):  
Escherichia Coli ◽  
Magnetic Nanoparticles ◽  
Iron Nanoparticles ◽  
Most Probable Number ◽  
Leaf Extracts ◽  
Probable Number ◽  
Gram Negative ◽  
E Coli ◽  
Tridax Procumbens ◽  
Escherichia Coli Bacteria

Objective: The present study was aimed at the biological synthesis of magnetic iron nanoparticles by using the plant extract of Tridax procumbens and also to study their antimicrobial property against gram-negative bacteria (Escherichia coli). Methods: The synthesis of magnetic iron nanoparticles was carried out by the co-precipitation method using biological methods like plant extract as reducing agent and capping agents are biocompatible and non-hazardous. These nanoparticles were characterized by UV-Visible spectroscopy, XRD (X-Ray Diffraction), and SEM (Scanning Electron Microscope). As well as antibacterial activity of the nanoparticles was carried out by agar well diffusion method and Most Probable Number (MPN) method against gram-negative E. coli (Escherichia coli) bacteria. Results: The average crystallite size of Magnetic Nanoparticles (MNPs) was found to be 72 nm by X-ray diffraction. The optical absorption band at wavelengths of 240 nm and 402 nm was obtained from the UV Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (15±0.15 mm) at 2 mg/ml and 1 mg/ml concentration was found for Magnetic Nanoparticles. In the Most Probable Number (MPN) test it is seen that the bacterial count is reduced after adding synthesized NPs into the water sample. Conclusion: The results of the present study conclude that the Magnetic Nanoparticles synthesized using Tridax procumbens leaf extracts is found to be stable and show good antibacterial activity against gram-negative (Escherichia coli) bacteria.

scholarly journals Induction and control of the autolytic system of Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 26-34
Author(s):  
M Leduc ◽  
R Kasra ◽  
J van Heijenoort
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Acid Synthesis ◽  
Induction Method ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Carbonyl Cyanide ◽  
And Control ◽  
First Time ◽  
Induced Autolysis

Various methods of inducing autolysis of Escherichia coli cells were investigated, some being described here for the first time. For the autolysis of growing cells only induction methods interfering with the biosynthesis of peptidoglycan were taken into consideration, whereas with harvested cells autolysis was induced by rapid osmotic or EDTA shock treatments. The highest rates of autolysis were observed after induction by moenomycin, EDTA, or cephaloridine. The different autolyses examined shared certain common properties. In particular, regardless of the induction method used, more or less extensive peptidoglycan degradation was observed, and 10(-2) M Mg2+ efficiently inhibited the autolytic process. However, for other properties a distinction was made between methods used for growing cells and those used for harvested cells. Autolysis of growing cells required RNA, protein, and fatty acid synthesis. No such requirements were observed with shock-induced autolysis performed with harvested cells. Thus, the effects of Mg2+, rifampicin, chloramphenicol, and cerulenin clearly suggest that distinct factors are involved in the control of the autolytic system of E. Coli. Uncoupling agents such as sodium azide, 2,4-dinitrophenol, and carbonyl-cyanide-m-chlorophenyl hydrazone used at their usual inhibiting concentration had no effect on the cephaloridine or shock-induced autolysis.

Functionalized Polymers as Receptors for Detection of Cells

2011 ◽  
Vol 64 (9) ◽  
pp. 1256 ◽  
Author(s):  
Miroslava Polreichova ◽  
Usman Latif ◽  
Franz L. Dickert
Keyword(s):  
Soft Lithography ◽  
Quartz Crystal ◽  
Coli Strain ◽  
Yeast Cells ◽  
Label Free ◽  
Sensitive Material ◽  
E Coli ◽  
Label Free Detection ◽  
Quartz Crystal Microbalances ◽  
Cell Strains

Mass sensitive sensors were applied for fast and label-free detection of bio-analytes. Robust and miniaturized sensor devices were fabricated by combining bio-mimetic imprinted surfaces with quartz crystal microbalances for the analysis of yeast and bacteria cells. These sensors allow us to differentiate between different growing stages of yeast cells. Moreover, the viability of cells was detected by structuring quartz crystal microbalance electrodes like a grid. Artificial yeast cells were produced to pattern the recognition layer, giving reversible enrichment of the respective bio-analytes. This approach was followed to ensure the reproducibility of the identical sensitive material in each case, because the properties of each cell depend on its growth stage, which varies over time. The strategy was further applied to develop a sensitive system for Escherichia coli. Structuring of these materials by soft lithography allows differentiation between cell strains, e.g. E. coli (strain W & B) with a five-fold selectivity.

Plasma catecholamines during E. coli bacteremia in conscious rats

1988 ◽  
Vol 254 (3) ◽  
pp. R470-R477 ◽  
Author(s):  
S. B. Jones ◽  
M. V. Westfall ◽  
M. M. Sayeed
Keyword(s):  
Escherichia Coli ◽  
Heart Rate ◽  
Plasma Catecholamines ◽  
Male Rats ◽  
Plasma Samples ◽  
Sympathetic Activation ◽  
Plasma Lactate ◽  
E Coli ◽  
Arterial Plasma ◽  
Escherichia Coli Bacteria

Fasted, conscious male rats, prepared with arterial and venous cannulas, were given doses (10(10)-10(11) organisms/kg) of live Escherichia coli bacteria. Heart rate and blood pressure were recorded, and arterial plasma samples were taken preinjection and at 30, 180, and 360 min after bacterial administration. Plasma was analyzed for lactate, glucose, norepinephrine (NE), and epinephrine (E). Rats given E. coli were normotensive but with significant tachycardia (P less than 0.05 vs. saline). Plasma NE and E levels increased severalfold during bacteremia (P less than 0.05 for all comparisons). Rats were euglycemic but had a sixfold increase in lactate 6 h (P less than 0.05) after E. coli treatment. Additional rats were subjected to the same protocol but had been made tolerant to bacterial endotoxin by multiple injections over the course of several days. Endotoxin-tolerant rats were also tolerant to live E. coli administration (P less than 0.05, 24 h survival) and had significantly reduced levels of E and NE at 6 h compared with nontolerant bacteremic rats (P less than 0.05). Increases in heart rate and plasma lactate were not significant in endotoxin-tolerant rats. These results suggest profound sympathetic activation during acute bacteremia with attenuated activation in endotoxin-tolerant rats. Tolerance appears to reduce the afferent stimuli that are presumably activated during the course of bacteremia.

scholarly journals A New 3-Prenyl-2-flavene and Other Extractives from Baphia massaiensis and Their Antimicrobial Activities

2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Ngonye Keroletswe ◽  
Runner R. T. Majinda ◽  
Ishmael B. Masesane
Keyword(s):  
Escherichia Coli ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
Spectroscopic Techniques ◽  
Good Activity ◽  
Gram Negative ◽  
E Coli ◽  
Chromatographic Techniques ◽  
Inhibition Zones ◽  
First Time

One new 3-prenyl-2-flavene, named baphiflavene A, 1, and eleven known compounds, 2-12, were isolated and reported for the first time from Baphia massaiensis using several chromatographic techniques. Their structures were elucidated using different spectroscopic techniques; 1D and 2D-NMR, HRMS, GC-MS, UV/Vis, FTIR and by comparison with literature data. The isolates were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans to establish their preliminary antimicrobial activities. The results revealed that compound 1 had moderate activities against both Gram positive ( B. subtilis and S. aureus) and Gram negative ( E. coli and P. aeruginosa) bacteria, and good activity against C. albicans with inhibition zones of 10–23 mm (compared to 19 mm for chloramphenicol and miconazole standards). To the best of our knowledge, this is the first phytochemical work reported on Baphia massaiensis.

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