scholarly journals Profluorescent Fluoroquinolone-Nitroxides for Investigating Antibiotic–Bacterial Interactions

Antibiotics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 19 ◽  
Author(s):  
Anthony Verderosa ◽  
Rabeb Dhouib ◽  
Kathryn Fairfull-Smith ◽  
Makrina Totsika
Keyword(s):  
Fluorescent Probes ◽  
Antimicrobial Properties ◽  
Chemical Processes ◽  
Cell Entry ◽  
Fluorescence Signal ◽  
Bacterial Cells ◽  
Significant Suppression ◽  
Bacterial Interactions ◽  
Radical Trapping ◽  
Nitroxide Probe

Fluorescent probes are widely used for imaging and measuring dynamic processes in living cells. Fluorescent antibiotics are valuable tools for examining antibiotic–bacterial interactions, antimicrobial resistance and elucidating antibiotic modes of action. Profluorescent nitroxides are ‘switch on’ fluorescent probes used to visualize and monitor intracellular free radical and redox processes in biological systems. Here, we have combined the inherent fluorescent and antimicrobial properties of the fluoroquinolone core structure with the fluorescence suppression capabilities of a nitroxide to produce the first example of a profluorescent fluoroquinolone-nitroxide probe. Fluoroquinolone-nitroxide (FN) 14 exhibited significant suppression of fluorescence (>36-fold), which could be restored via radical trapping (fluoroquinolone-methoxyamine 17) or reduction to the corresponding hydroxylamine 20. Importantly, FN 14 was able to enter both Gram-positive and Gram-negative bacterial cells, emitted a measurable fluorescence signal upon cell entry (switch on), and retained antibacterial activity. In conclusion, profluorescent nitroxide antibiotics offer a new powerful tool for visualizing antibiotic–bacterial interactions and researching intracellular chemical processes.

scholarly journals Zinc Oxide Nanocomposites—Extracellular Synthesis, Physicochemical Characterization and Antibacterial Potential

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4347 ◽  
Author(s):  
Paweł Pomastowski ◽  
Anna Król-Górniak ◽  
Viorica Railean-Plugaru ◽  
Bogusław Buszewski
Keyword(s):  
Control Sample ◽  
Physicochemical Characterization ◽  
Microscopic Analysis ◽  
Luminescent Properties ◽  
Infrared Range ◽  
Fluorescence Signal ◽  
Bacterial Cells ◽  
Ointment Formulation ◽  
Ph Range ◽  
Organic Deposits

This research presents, for the first time, the potential of the Lactobacillus paracasei LC20 isolated from sweet whey as a novel, effective and accessible source for post-cultured ZnO nanocomposites synthesis. The obtained nanocomposites were subjected to comprehensive characterization by a broad spectrum of instrumental techniques. Results of spectroscopic and microscopic analysis confirmed the hexagonal crystalline structure of ZnO in the nanometer size. The dispersion stability of the obtained nanocomposites was determined based on the zeta potential (ZP) measurements—the average ZP value was found to be −29.15 ± 1.05 mV in the 7–9 pH range. The ZnO nanocomposites (NCs) demonstrated thermal stability up to 130 °C based on the results of thermogravimetric TGA/DTG) analysis. The organic deposit on the nanoparticle surface was recorded by spectroscopic analysis in the infrared range (FT-IR). Results of the spectrometric study exhibited nanostructure-assisted laser desorption/ionization effects and also pointed out the presence of organic deposits and, what is more, allowed us to identify the specific amino acids and peptides present on the ZnO NCs surfaces. In this context, mass spectrometry (MS) data confirmed the nano-ZnO formation mechanism. Moreover, fluorescence data showed an increase in fluorescence signal in the presence of nanocomposites designed for potential use as, e.g., biosensors. Despite ZnO NCs’ luminescent properties, they can also act as promising antiseptic agents against clinically relevant pathogens. Therefore, a pilot study on the antibacterial activity of biologically synthesized ZnO NCs was carried out against four strains (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa) by using MIC (minimal inhibitory concentration). Additionally, the colony forming units (CFU) assay was performed and quantified for all bacterial cells as the percentage of viable cells in comparison to a control sample (untreated culture) The nanocomposites were effective among three pathogens with MIC values in the range of 86.25–172.5 μg/mL and showed potential as a new type of, e.g., medical path or ointment formulation.

Nanocarrier-Based Biological Fluorescent Probes for Simultaneous Detection of Ketamine and Amphetamine in Latent Fingermarks

NANO ◽  
2019 ◽  
Vol 14 (02) ◽  
pp. 1950026 ◽  
Author(s):  
Jing Zhou ◽  
Gaoling Zhao ◽  
Wangwei Lu ◽  
Lingtong Zhan ◽  
Gaorong Han
Keyword(s):  
Fluorescent Probes ◽  
Simultaneous Detection ◽  
Personal Identification ◽  
Step Test ◽  
Individual Identification ◽  
Fluorescence Signal ◽  
Fluorescent Nanoparticles ◽  
Functional Roles ◽  
Dual Functional ◽  
Green Fluorescent

Nanocarrier-based biological fluorescent probes for ketamine and amphetamine have been prepared by conjugating red and green fluorescent nanoparticles (150-nm-sized) with anti-ketamine and anti-amphetamine antibodies, respectively, with the assistance of carbodiimide/[Formula: see text]-hydroxysuccinimide. Biological fluorescent probes for ketamine and amphetamine could simultaneously detect these two drugs within a single fingermark by one-step test. Nanoparticles as carrier played dual-functional roles for not only fingermark visualization but also drug recognition. Latent fingermarks were visualized by the fluorescence signal generated from nanoparticles. The developed fingermarks clearly revealed ridge pattern and sufficient minutiae for individual identification. Ketamine and amphetamine were recognized by simply observing the colors of fluorescent images when the fingermark was checked in red and green channels. Detection limit of ketamine or amphetamine was 50[Formula: see text]ng in fingermark. This work therefore provides a novel nanocarrier-based strategy of drug detection as well as personal identification with high selectivity, low background interference and fast testing, which can be further broadened to other drugs and molecules.

Theoretical design and investigation of 1,8-naphthalimide-based two-photon fluorescent probes for detecting cytochrome P450 1A with separated fluorescence signal

2018 ◽  
Vol 20 (19) ◽  
pp. 13290-13305 ◽  
Author(s):  
Chun Zhang ◽  
Ai-Min Ren ◽  
Jing-Fu Guo ◽  
Dan Wang ◽  
Li-Ying Yu
Keyword(s):  
Cytochrome P450 ◽  
Fluorescent Probe ◽  
Fluorescent Probes ◽  
Fluorescence Signal ◽  
Two Photon ◽  
Theoretical Design ◽  
Cytochrome P450 1A

Two-photon fluorescent probe for detecting CYP1A enzyme with separated fluorescence signal.

scholarly journals Impact of an Engineered Copper-Titanium Dioxide Nanocomposite and Parent Substrates on the Bacteria Viability, Antioxidant Enzymes and Fatty Acid Profiling

2020 ◽  
Vol 21 (23) ◽  
pp. 9089
Author(s):  
Oliwia Metryka ◽  
Daniel Wasilkowski ◽  
Anna Nowak ◽  
Małgorzata Adamczyk-Habrajska ◽  
Agnieszka Mrozik
Keyword(s):  
Antioxidant Enzymes ◽  
Fatty Acid ◽  
Opposite Effect ◽  
Antimicrobial Properties ◽  
Bacterial Cells ◽  
Fatty Acid Profiles ◽  
Tio2 Nps ◽  
E Coli ◽  
Fatty Acid Profiling ◽  
Life Issues

Due to the systematic increase in the production of nanomaterials (NMs) and their applications in many areas of life, issues associated with their toxicity are inevitable. In particular, the performance of heterogeneous NMs, such as nanocomposites (NCs), is unpredictable as they may inherit the properties of their individual components. Therefore, the purpose of this work was to assess the biological activity of newly synthesized Cu/TiO2-NC and the parent nanoparticle substrates Cu-NPs and TiO2-NPs on the bacterial viability, antioxidant potential and fatty acid composition of the reference Escherichia coli and Bacillus subtilis strains. Based on the toxicological parameters, it was found that B. subtilis was more sensitive to NMs than E. coli. Furthermore, Cu/TiO2-NC and Cu-NPs had an opposite effect on both strains, while TiO2-NPs had a comparable mode of action. Simultaneously, the tested strains exhibited varied responses of the antioxidant enzymes after exposure to the NMs, with Cu-NPs having the strongest impact on their activity. The most considerable alternations in the fatty acid profiles were found after the bacteria were exposed to Cu/TiO2-NC and Cu-NPs. Microscopic images indicated distinct interactions of the NMs with the bacterial outer layers, especially in regard to B. subtilis. Cu/TiO2-NC generally proved to have less distinctive antimicrobial properties on B. subtilis than E. coli compared to its parent components. Presumably, the biocidal effects of the tested NMs can be attributed to the induction of oxidative stress, the release of metal ions and specific electrochemical interactions with the bacterial cells.

Granule contents from rat polymorphonuclear leukocytes: antimicrobial properties and characterization

1986 ◽  
Vol 32 (6) ◽  
pp. 498-504 ◽  
Author(s):  
Richard L. Hodinka ◽  
Malcolm C. Modrzakowski
Keyword(s):  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bacterial Cells ◽  
Gram Positive Bacteria ◽  
Properties And Characterization ◽  
Bacterial Mutants ◽  
Killing Action ◽  
Gram Negative Organisms ◽  
Ph Range ◽  
Static Conditions

The nonoxidative antibacterial properties of isolated rat polymorphonuclear leukocyte granule contents were examined using Salmonella typhimurium LT-2 and a series of progressively rough lipopolysaccharide mutants of this strain as target bacteria. The granule extract was most active at 37 °C, with a substantial decrease in activity observed at lower temperatures. Deep rough bacterial mutants were killed best within a pH range of 6–8, while killing of mutants with increased lipopolysaccharide content was most efficient at an acid pH of 5. The activity of the extract was dependent on incubation time but was independent of the number of bacterial cells present in the assay mixture. The killing action of the granule extract was inhibited by the cations Na+, K+, Mg2+, Ca, and Fe2+. The degree of inhibition was dependent on the type and concentration of ion used. Rough mutants grown with aeration to log phase were killed more efficiently than the same mutants grown to stationary phase under static conditions. Also, gram-positive bacteria were more susceptible to the extract than were gram-negative organisms.

scholarly journals Antibacterial Composite Layers on Ti: Role of ZnO Nanoparticles

2016 ◽  
Vol 61 (1) ◽  
pp. 213-216
Author(s):  
A. Roguska ◽  
A. Belcarz ◽  
P. Suchecki ◽  
M. Andrzejczuk ◽  
M. Lewandowska
Keyword(s):  
Zno Nanoparticles ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Bacterial Cells ◽  
Metallic Oxide ◽  
Moderate Amount ◽  
Orthopaedic Infections ◽  
Composite Layers ◽  
Biomedical Coatings

Problem of Post-operative infections of implant materials caused by bacterial adhesion to their surfaces is very serious. Enhancement of antibacterial properties is potentially beneficial for biomaterials value. Therefore, the metallic and metallic oxide nanoparticles attract particular attention as antimicrobial factors. The aim of this work was to create nanotubular (NT) oxide layers on Ti with the addition of ZnO nanoparticles, designed for antibacterial biomedical coatings. Antimicrobial activities of titanium, TiO2NT and ZnO/TiO2NT surfaces were evaluated against bacterial strain typical for orthopaedic infections: S. epidermidis. TiO2NT alone killed the free bacterial cells significantly but promoted their adhesion to the surfaces. The presence of moderate amount of ZnO nanoparticles significantly reduced the S. epidermidis cells adhesion and viability of bacterial cells in contact with modified surfaces. However, higher amount of loaded nanoZnO showed the reduced antimicrobial properties than the medium amount, suggesting the overdose effect.

scholarly journals Antibacterial Composite Layers on Ti: Role of ZnO Nanoparticles

2016 ◽  
Vol 61 (2) ◽  
pp. 937-940 ◽  
Author(s):  
A. Roguska ◽  
A. Belcarz ◽  
P. Suchecki ◽  
M. Andrzejczuk ◽  
M. Lewandowska
Keyword(s):  
Zno Nanoparticles ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Bacterial Cells ◽  
Metallic Oxide ◽  
Moderate Amount ◽  
Orthopaedic Infections ◽  
Composite Layers ◽  
Biomedical Coatings

Abstract Problem of post-operative infections of implant materials caused by bacterial adhesion to their surfaces is very serious. Enhancement of antibacterial properties is potentially beneficial for biomaterials value. Therefore, the metallic and metallic oxide nanoparticles attract particular attention as antimicrobial factors. The aim of this work was to create nanotubular (NT) oxide layers on Ti with the addition of ZnO nanoparticles, designed for antibacterial biomedical coatings. Antimicrobial activities of titanium, TiO2 NT and ZnO/TiO2 NT surfaces were evaluated against bacterial strain typical for orthopaedic infections: S. epidermidis. TiO2 NT alone killed the free bacterial cells significantly but promoted their adhesion to the surfaces. The presence of moderate amount of ZnO nanoparticles significantly reduced the S. epidermidis cells adhesion and viability of bacterial cells in contact with modified surfaces. However, higher amount of loaded nanoZnO showed the reduced antimicrobial properties than the medium amount, suggesting the overdose effect.

The antimicrobial properties of new synthetic porphyrins

2003 ◽  
Vol 07 (11) ◽  
pp. 755-760 ◽  
Author(s):  
Tatyana O. Philippova ◽  
Boris N. Galkin ◽  
Oksana Yu. Zinchenko ◽  
Maria Yu. Rusakova ◽  
Vladimir A. Ivanitsa ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antimicrobial Properties ◽  
Middle Level ◽  
Membrane Receptors ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Free Base ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

The antimicrobial activity of new meso-tetrakis(N-methyl-6-quinolinyl)-substituted porphyrins and meso-tetrakis(N-methyl-6-quinolinyl)-substituted chlorins is described. The dark toxicity and photosensitising potentials of free-base (TQP and TQC) and its Sn(IV)-complexes [(TQP)Sn(IV) and (TQC)Sn(IV)] were tested on Gram-positive (Staphylococus aureus), Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and two species of yeasts (Candida albicans and Rhodotorula bogoriensis). The results described in this paper show that TQP and (TQP)Sn(IV) did not inhibit the growth of S. aureus in the dark, but efficiently photosensitize the inactivation of this Gram-positive bacteria. These porphyrins have no appreciable photosensitizing activity towards Gram-negative bacteria. However, (TQP)Sn(IV) shows high dark toxicity against E. coli and P. aeruginosa. The free-base derivatives demonstrated dark activity only in the case of P. aeruginosa. We suppose that these meso-tetrakis(N-methyl-6-quinolinyl)-substituted porphyrins can bind to the Gram-negative bacteria outer membrane receptors that transported vitamin B12. The meso-substituted chlorins TQC and (TQC)Sn(IV) have shown similar efficiency in the dark- and photoinactivation of S. aureus. They revealed a middle level of dark toxicity towards Gram-negative bacteria. The Sn(IV)-complex of chlorin in comparison with free base and metalloporphyrins are more effective in photoinactivation of Gram-negative bacteria. Yeasts, such as Candida albicans and Rhodotorula bogoriensis are more sensitive to photodynamic inactivation as bacterial cells. The effects of (TQP)Sn(IV) and (TQC)Sn(IV) are more expressed than effects of free bases.

scholarly journals Antimicrobial Properties of Magnesium Open Opportunities to Develop Healthier Food

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2363 ◽  
Author(s):  
Keren Demishtein ◽  
Ram Reifen ◽  
Moshe Shemesh
Keyword(s):  
Human Body ◽  
Biofilm Formation ◽  
Dairy Products ◽  
Antibacterial Effect ◽  
Antimicrobial Properties ◽  
Enzymatic Reactions ◽  
Bacterial Cells ◽  
Magnesium Ions ◽  
The Past ◽  
New Information

Magnesium is a vital mineral that takes part in hundreds of enzymatic reactions in the human body. In the past several years, new information emerged in regard to the antibacterial effect of magnesium. Here we elaborate on the recent knowledge of its antibacterial effect with emphasis on its ability to impair bacterial adherence and formation complex community of bacterial cells called biofilm. We further talk about its ability to impair biofilm formation in milk that provides opportunity for developing safer and qualitative dairy products. Finally, we describe the pronounced advantages of enrichment of food with magnesium ions, which result in healthier and more efficient food products.

scholarly journals Postbiotics, as Dynamic Biomolecules, and Their Promising Role in Promoting Food Safety

2021 ◽  
Vol 11 (6) ◽  
pp. 14529-14544
Keyword(s):  
Food Safety ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Energy Regulation ◽  
Bacterial Cells ◽  
Food Spoilage ◽  
New Approach ◽  
Functional Changes ◽  
Food Borne ◽  
Bacterial Cell Membrane

Many factors threaten food safety, such as physical, chemical, and biological hazards. In this regard, biological hazards are of paramount importance. Among them, the bacteria play important roles in causing food spoilage and food-borne diseases. Besides, a new approach has been used in recent years, which is based on probiotics and postbiotics to control the growth of pathogenic germs and their mediated corruption due to their significant antimicrobial properties. The outcomes of recent investigations suggest that postbiotics might be appropriate alternative elements for probiotic cells and can be employed as novel antimicrobial agents. The main antimicrobial mechanisms of postbiotics include acidifying the cellular cytoplasm and preventing energy regulation and production, suppressing the growth of pathogenic microorganisms by the formation of pores in cell membranes, and morphological and functional changes of sensitive components such as proteins and peptides by creating acidity in the bacterial cell membrane as well as inducing the oxidation of bacterial cells. Therefore, presently scientific literature approves that postbiotics can be applied as promising tools in food practice to prevent microbial corruption and develop functional foods due to their unique features. This review addresses the latest postbiotic applications with regards to food safety. Potential postbiotic applications in the inhibition of food spoilage and pathogenic microbes, food biopreservation, and biofilm control are also reviewed.

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