scholarly journals A Bioinspired Peptide in TIR Protein as Recognition Molecule on Electrochemical Biosensors for the Detection of E. coli O157:H7 in an Aqueous Matrix

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2559
Author(s):  
Jose Luis Ropero-Vega ◽  
Joshua Felipe Redondo-Ortega ◽  
Yuli Juliana Galvis-Curubo ◽  
Paola Rondón-Villarreal ◽  
Johanna Marcela Flórez-Castillo
Keyword(s):  
Protein A ◽  
Fast Response ◽  
Electrochemical Characteristics ◽  
Selective Detection ◽  
E Coli ◽  
Recognition Element ◽  
Sensitivity And Selectivity ◽  
User Friendly ◽  
First Time ◽  
Recognition Molecule

Currently, the detection of pathogens such as Escherichia coli through instrumental alternatives with fast response and excellent sensitivity and selectivity are being studied. Biosensors are systems consisting of nanomaterials and biomolecules that exhibit remarkable properties such as simplicity, portable, affordable, user‑friendly, and deliverable to end‑users. For this, in this work we report for the first time, to our knowledge, the bioinformatic design of a new peptide based on TIR protein, a receptor of Intimin membrane protein which is characteristic of E. coli. This peptide (named PEPTIR‑1.0) was used as recognition element in a biosensor based on AuNPs‑modified screen‑printed electrodes for the detection of E. coli. The morphological and electrochemical characteristics of the biosensor obtained were studied. Results show that the biosensor can detect the bacteria with limits of detection and quantification of 2 and 6 CFU/mL, respectively. Moreover, the selectivity of the system is statistically significant towards the detection of the pathogen in the presence of other microorganisms such as P. aeruginosa and S. aureus. This makes this new PEPTIR‑1.0 based biosensor can be used in the rapid, sensitive, and selective detection of E. coli in aqueous matrices.

scholarly journals Evidence for Direct Protein-Protein Interaction between Members of the Enterobacterial Hha/YmoA and H-NS Families of Proteins

2002 ◽  
Vol 184 (3) ◽  
pp. 629-635 ◽  
Author(s):  
J. M. Nieto ◽  
C. Madrid ◽  
E. Miquelay ◽  
J. L. Parra ◽  
S. Rodríguez ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Protein A ◽  
Nitrilotriacetic Acid ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis ◽  
E Coli ◽  
Protein Protein Interaction ◽  
New Family ◽  
Missense Mutant ◽  
First Time

ABSTRACT Escherichia coli nucleoid-associated H-NS protein interacts with the Hha protein, a member of a new family of global modulators that also includes the YmoA protein from Yersinia enterocolitica. This interaction has been found to be involved in the regulation of the expression of the toxin α-hemolysin. In this study, we further characterize the interaction between H-NS and Hha. We show that the presence of DNA in preparations of copurified His-Hha and H-NS is not directly implicated in the interaction between the proteins. The precise molecular mass of the H-NS protein retained by Hha, obtained by mass spectrometry analysis, does not show any posttranslational modification other than removal of the N-terminal Met residue. We constructed an H-NS-His recombinant protein and found that, as expected, it interacts with Hha. We used a Ni2+-nitrilotriacetic acid agarose method for affinity chromatography copurification of proteins to identify the H-NS protein of Y. enterocolitica. We constructed a six-His-YmoA recombinant protein derived from YmoA, the homologue of Hha in Y. enterocolitica, and found that it interacts with Y. enterocolitica H-NS. We also cloned and sequenced the hns gene of this microorganism. In the course of these experiments we found that His-YmoA can also retain H-NS from E. coli. We also found that the hns gene of Y. enterocolitica can complement an hns mutation of E. coli. Finally, we describe for the first time systematic characterization of missense mutant alleles of hha and truncated Hha′ proteins, and we report a striking and previously unnoticed similarity of the Hha family of proteins to the oligomerization domain of the H-NS proteins.

scholarly journals HERMES: a molecular formula-oriented method to target the metabolome

2021 ◽  
Author(s):  
Roger Giné ◽  
Jordi Capellades ◽  
Josep M. Badia ◽  
Dennis Vughs ◽  
Michaela Schwaiger-Haber ◽  
...  
Keyword(s):  
Data Analysis ◽  
Environmental Water ◽  
R Package ◽  
Molecular Formula ◽  
Structural Annotation ◽  
Mass Spectral ◽  
E Coli ◽  
Sensitivity And Selectivity ◽  
User Friendly ◽  
Suboptimal Strategies

ABSTRACTComprehensive metabolome analyses are hampered by low identification rates of metabolites due to suboptimal strategies in MS and MS2 acquisition, and data analysis. Here we present a molecular formula-oriented and peak detection-free method, HERMES, that improves sensitivity and selectivity for metabolite profiling in MS and structural annotation in MS2. An analysis of environmental water, E. coli, and human plasma extracts by HERMES showed increased biological specificity of MS2 scans, leading to improved mass spectral similarity scoring and identification rates when compared to iterative data-dependent acquisition (DDA). HERMES is available as an R package with a user-friendly graphical interface to allow data analysis and interactive tracking of compound annotations.

A novel FRET-based fluorescent probe for the selective detection of hydrogen sulfide (H2S) and its application for bioimaging

2018 ◽  
Vol 6 (30) ◽  
pp. 4903-4908 ◽  
Author(s):  
Qi Zhao ◽  
Fangjun Huo ◽  
Jin Kang ◽  
Yongbin Zhang ◽  
Caixia Yin
Keyword(s):  
Hydrogen Sulfide ◽  
Detection Limit ◽  
Fluorescent Probe ◽  
Nude Mice ◽  
High Sensitivity ◽  
Fast Response ◽  
Living Cells ◽  
Selective Detection ◽  
Low Detection Limit ◽  
Sensitivity And Selectivity

Herein, our group developed a fast response fluorescent probe (Flu-N3) for H2S on the basis of the 7-amino-4-methylcoumarin and fluorescein FRET system with high sensitivity and selectivity and a low detection limit of 0.031 μM. Moreover, the probe was successfully applied to image exogenous and endogenous H2S in living cells and nude mice.

scholarly journals Novel Model To Study Virulence Determinants of Escherichia coli K1

2007 ◽  
Vol 75 (12) ◽  
pp. 5735-5739 ◽  
Author(s):  
Naveed Ahmed Khan ◽  
Graham John Goldsworthy
Keyword(s):  
Escherichia Coli ◽  
Protein A ◽  
Deletion Mutants ◽  
Virulence Determinants ◽  
E Coli ◽  
K 12 ◽  
Cytotoxic Necrotizing Factor 1 ◽  
First Time ◽  
The Brain

ABSTRACT It is shown here for the first time that locusts can be used as a model to study Escherichia coli K1 pathogenesis. E. coli K-12 strain HB101 has very low pathogenicity to locusts and does not invade the locust brain, whereas the injection of 2 × 106 E. coli K1 strain RS218 (O18:K1:H7) kills almost 100% of locusts within 72 h and invades the brain within 24 h of injection. Both mortality and invasion of the brain in locusts after injection of E. coli K1 require at least two of the known virulence determinants shown for mammals. Thus, deletion mutants that lack outer membrane protein A or cytotoxic necrotizing factor 1 have reduced abilities to kill locusts and to invade the locust brain compared to the parent E. coli K1. Interestingly, deletion mutants lacking FimH or the NeuDB gene cluster are still able to cause high mortality. It is argued that the likely existence of additional virulence determinants can be investigated in vivo by using this insect system.

scholarly journals Electrochromic Performance and Capacitor Performance of α-MoO3 Nanorods Fabricated by a One-Step Procedure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Ying Duan ◽  
Chen Wang ◽  
Jian Hao ◽  
Yang Jiao ◽  
Yanchao Xu ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Fast Response ◽  
Cycle Stability ◽  
Electrochromic Devices ◽  
Step Procedure ◽  
One Step ◽  
Supercapacitor Performance ◽  
First Time ◽  
Prepared Nanorods

In this paper, we propose for the first time the synthesis of α-MoO3 nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO3 nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO3 nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO3 nanorods may be good candidates for applications in electrochromic devices and supercapacitors.

scholarly journals Efficacy of compressed sodium chloride (CSC) against E. coli and Candida auris in minutes and methods improvement for testing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lan N. Truong ◽  
Brayden D. Whitlock
Keyword(s):  
Sodium Chloride ◽  
Improved Method ◽  
Candida Auris ◽  
Antimicrobial Surfaces ◽  
E Coli ◽  
Route Of Transmission ◽  
The World ◽  
Short Time ◽  
First Time ◽  
Time Point

AbstractControlling infections has become one of the biggest problems in the world, whether measured in lives lost or money spent. This is worsening as pathogens continue becoming resistant to therapeutics. Antimicrobial surfaces are one strategy being investigated in an attempt to decrease the spread of infections through the most common route of transmission: surfaces, including hands. Regulators have chosen two hours as the time point at which efficacy should be measured. The objectives of this study were to characterize the new antimicrobial surface compressed sodium chloride (CSC) so that its action may be understood at timepoints more relevant to real-time infection control, under two minutes; to develop a sensitive method to test efficacy at short time points; and to investigate antifungal properties for the first time. E. coli and Candida auris are added to surfaces, and the surfaces are monitored by contact plate, or by washing into collection vats. An improved method of testing antimicrobial efficacy is reported. Antimicrobial CSC achieves at least 99.9% reduction of E. coli in the first two minutes of contact, and at least 99% reduction of C. auris in one minute.

scholarly journals Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Food Industry ◽  
Balkan Peninsula ◽  
Antimicrobial Activities ◽  
Natural Sources ◽  
E Coli ◽  
Food Borne ◽  
Metabolite Profiles ◽  
Aspergillus Sp ◽  
First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

scholarly journals Integrating virtual reality in qualitative research methods: Making a case for the VR-assisted interview

2021 ◽  
Vol 14 (2) ◽  
pp. 205979912110307
Author(s):  
Dennis Mathysen ◽  
Ignace Glorieux
Keyword(s):  
Virtual Reality ◽  
Social Science ◽  
Social Science Research ◽  
Science Research ◽  
Structured Interview ◽  
Good Effect ◽  
Valuable Alternative ◽  
Specialized Hardware ◽  
User Friendly ◽  
First Time

Virtual reality (VR) is still very much a niche technology despite its increasing popularity since recent years. VR has now reached a point where it can offer photorealistic experiences, while also being consumer-friendly and affordable. However, so far only a very limited amount of software has been developed for the specific purpose of conducting (social science) research. In this article, we illustrate that integrating virtual reality to good effect in social science research does not necessarily require specialized hardware or software, an abundance of expertise regarding VR-technology or even a large budget. We do this by discussing our use of a method we have come to call ‘VR-assisted interviews’: conducting a (semi-structured) interview while respondents are confronted with a virtual environment viewed via a VR-headset. This method allows respondents to focus on what they are seeing and experiencing, instead of having them worry about how to operate a device and navigate an interface they are using for the first time. ‘VR-assisted interviews’ are very user-friendly for respondents but also limits options for interactiveness. We believe this method can be a valuable alternative, both because of methodological and practical considerations, for more complex applications of VR-technology in social science research.

scholarly journals Radical Dehalogenation and Purine Nucleoside Phosphorylase E. coli: How Does an Admixture of 2′,3′-Anhydroinosine Hinder 2-fluoro-cordycepin Synthesis

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 539
Author(s):  
Alexey L. Kayushin ◽  
Julia A. Tokunova ◽  
Ilja V. Fateev ◽  
Alexandra O. Arnautova ◽  
Maria Ya. Berzina ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Synthesis ◽  
Purine Nucleoside Phosphorylase ◽  
Purine Nucleoside ◽  
Preparative Synthesis ◽  
Nucleoside Phosphorylase ◽  
E Coli ◽  
First Time

During the preparative synthesis of 2-fluorocordycepin from 2-fluoroadenosine and 3′-deoxyinosine catalyzed by E. coli purine nucleoside phosphorylase, a slowdown of the reaction and decrease of yield down to 5% were encountered. An unknown nucleoside was found in the reaction mixture and its structure was established. This nucleoside is formed from the admixture of 2′,3′-anhydroinosine, a byproduct in the preparation of 3-′deoxyinosine. Moreover, 2′,3′-anhydroinosine forms during radical dehalogenation of 9-(2′,5′-di-O-acetyl-3′-bromo- -3′-deoxyxylofuranosyl)hypoxanthine, a precursor of 3′-deoxyinosine in chemical synthesis. The products of 2′,3′-anhydroinosine hydrolysis inhibit the formation of 1-phospho-3-deoxyribose during the synthesis of 2-fluorocordycepin. The progress of 2′,3′-anhydroinosine hydrolysis was investigated. The reactions were performed in D2O instead of H2O; this allowed accumulating intermediate substances in sufficient quantities. Two intermediates were isolated and their structures were confirmed by mass and NMR spectroscopy. A mechanism of 2′,3′-anhydroinosine hydrolysis in D2O is fully determined for the first time.

scholarly journals Antimicrobial Activity of L-Lysine and Poly-L-Lysine with Pulsed Electric Fields

2021 ◽  
Vol 11 (6) ◽  
pp. 2708
Author(s):  
Jurgita Švedienė ◽  
Vitalij Novickij ◽  
Rokas Žalnėravičius ◽  
Vita Raudonienė ◽  
Svetlana Markovskaja ◽  
...  
Keyword(s):  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Antimicrobial Treatment ◽  
Treatment Development ◽  
E Coli ◽  
Yeast Fungi ◽  
New Treatment ◽  
First Time ◽  
Resistant Microorganism ◽  
Susceptibility Patterns

For the first time, the possibility to use L-lysine (Lys) and poly-L-lysine (PLL) as additives with pulsed electric fields (PEF) for antimicrobial treatment is reported. The antimicrobial efficacy of Lys and PLL for Escherichia coli, Staphylococcus aureus, Trichophyton rubrum and Candida albicans was determined. Inactivation of microorganisms was also studied by combining Lys and PLL with PEF of 15 and 30 kV/cm. For PEF treatment, pulses of 0.5, 1, 10 or 100 μs were applied in a sequence of 10 to 5000 at 1 kHz frequency. The obtained results showed that 100 μs pulses were the most effective in combination with Lys and PLL for all microorganisms. Equivalent energy PEF bursts with a shorter duration of the pulse were less effective independently on PEF amplitude. Additionally, various treatment susceptibility patterns of microorganisms were determined and reported. In this study, the Gram-negative E. coli was the most treatment-resistant microorganism. Nevertheless, inactivation rates exceeding 2 log viability reduction were achieved for all analyzed yeast, fungi, and bacteria. This methodology could be used for drug-resistant microorganism’s new treatment development.

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