scholarly journals 18 GHz electromagnetic field induces permeability of Gram-positive cocci

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
The Hong Phong Nguyen ◽  
Yury Shamis ◽  
Rodney J. Croft ◽  
Andrew Wood ◽  
Robert L. McIntosh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Electromagnetic Field ◽  
Cell Permeability ◽  
Scanning Electron Micrographs ◽  
Bacterial Cells ◽  
Silica Nanospheres ◽  
Bacterial Strains ◽  
Bacterial Membranes ◽  
Transmission Electron ◽  
Gram Positive Cocci

Abstract The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP 65.8T, S. aureus ATCC 25923 and S. epidermidis ATCC 14990T, was investigated. We demonstrate that exposing the bacteria to an EMF induced permeability in the bacterial membranes of all strains studied, as confirmed directly by transmission electron microscopy (TEM) and indirectly via the propidium iodide assay and the uptake of silica nanospheres. The cells remained permeable for at least nine minutes after EMF exposure. It was shown that all strains internalized 23.5 nm nanospheres, whereas the internalization of the 46.3 nm nanospheres differed amongst the bacterial strains (S. epidermidis ATCC 14990T~ 0%; Staphylococcus aureus CIP 65.8T S. aureus ATCC 25923, ~40%; Planococcus maritimus KMM 3738, ~80%). Cell viability experiments indicated that up to 84% of the cells exposed to the EMF remained viable. The morphology of the bacterial cells was not altered, as inferred from the scanning electron micrographs, however traces of leaked cytosolic fluids from the EMF exposed cells could be detected. EMF-induced permeabilization may represent an innovative, alternative cell permeability technique for applications in biomedical engineering, cell drug delivery and gene therapy.

scholarly journals CdSe QD Biosynthesis in Yeast Using Tryptone-Enriched Media and Their Conjugation with a Peptide Hecate for Bacterial Detection and Killing

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1463 ◽  
Author(s):  
Vishma Pratap Sur ◽  
Marketa Kominkova ◽  
Zaneta Buchtova ◽  
Kristyna Dolezelikova ◽  
Ondrej Zitka ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synthesis Process ◽  
Synthesis Methods ◽  
Bacterial Cells ◽  
Cdse Qds ◽  
Yeast Saccharomyces Cerevisiae ◽  
Shape Distribution ◽  
Transmission Electron ◽  
A Cell ◽  
Physical And Chemical

The physical and chemical synthesis methods of quantum dots (QDs) are generally unfavorable for biological applications. To overcome this limitation, the development of a novel “green” route to produce highly-fluorescent CdSe QDs constitutes a promising substitute approach. In the present work, CdSe QDs were biosynthesized in yeast Saccharomyces cerevisiae using a novel method, where we showed for the first time that the concentration of tryptone highly affects the synthesis process. The optimum concentration of tryptone was found to be 25 g/L for the highest yield. Different methods were used to optimize the QD extraction from yeast, and the best method was found to be by denaturation at 80 °C along with an ultrasound needle. Multiple physical characterizations including transmission electron microscopy (TEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), and spectrophotometry confirmed the optical features size and shape distribution of the QDs. We showed that the novel conjugate of the CdSe QDs and a cell-penetrating peptide (hecate) can detect bacterial cells very efficiently under a fluorescent microscope. The conjugate also showed strong antibacterial activity against vancomycin-resistant Staphylococcus aureus (VRSA), methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli, which may help us to cope with the problem of rising antibiotic resistance.

scholarly journals Utilization of Mn-Doped ZnSe/ZnS Core/Shell Quantum Dots for Rapid Detection of Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Thi-Diem Bui ◽  
Quang-Liem Nguyen ◽  
Thi-Bich Luong ◽  
Van Thuan Le ◽  
Van-Dat Doan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Fluorescent Labeling ◽  
Core Shell ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
E Coli ◽  
Mn Doped

In this study, Mn-doped ZnSe/ZnS core/shell quantum dots (CSQDs) were synthesized in aqueous solution using polyethylene glycol as a surface stabilizer and successfully applied in the detection of Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) for the first time. The CSQDs were conjugated with anti-E. coli antibody and anti-MRSA antibody via protein A supported by 1-ethyl-3-(-3-dimethylaminopropyl)carbodiimide hydrochloride for fluorescent labeling of the intact bacterial cells. The detection was performed for the bacterial strains cultivated in Luria-Bertani liquid medium. The obtained results indicate that E. coli O157:H7 and MRSA can be detected within 30 min at a high sensitivity of 101 CFU/mL. This labeling method based on the highly fluorescent CSQDs may have great potential for use in the food industry to check and prevent outbreaks of foodborne illness.

scholarly journals Potential Use of Silica Nanoparticles for the Microbial Stabilisation of Wine: An In Vitro Study Using Oenococcus oeni as a Model

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1338
Author(s):  
Kamila Pachnowska ◽  
Krzysztof Cendrowski ◽  
Xymena Stachurska ◽  
Paweł Nawrotek ◽  
Adrian Augustyniak ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Oenococcus Oeni ◽  
Chemical Oxidation ◽  
Alternative Methods ◽  
Bacterial Cells ◽  
Silica Nanospheres ◽  
Cell Counts ◽  
Transmission Electron ◽  
Phosphate Buffered Saline

The emerging trend towards the reduction of SO2 in winemaking has created a need to look for alternative methods to ensure the protection of wine against the growth of undesired species of microorganisms and to safely remove wine microorganisms. This study describes the possible application of silica nanospheres as a wine stabilisation agent, with Oenococcus oeni (DSM7008) as a model strain. The experiment was conducted firstly on model solutions of phosphate-buffered saline and 1% glucose. Their neutralising effect was tested under stirring with the addition of SiO2 (0.1, 0.25, and 0.5 mg/mL). Overall, the highest concentration of nanospheres under continuous stirring resulted in the greatest decrease in cell counts. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses showed extensive damage to the bacterial cells after stirring with silica nanomaterials. Then, the neutralising effect of 0.5 mg/mL SiO2 was tested in young red wine under stirring, where cell counts were reduced by over 50%. The obtained results suggest that silica nanospheres can serve as an alternative way to reduce or substitute the use of sulphur dioxide in the microbial stabilisation of wine. In addition, further aspects of following investigations should focus on the protection against enzymatic and chemical oxidation of wine.

scholarly journals Vorinostat Pretreatment Enhanced Ciprofloxacin-Induced Antibacterial Activity

2016 ◽  
Author(s):  
Majed M. Masadeh ◽  
Karem H. Alzoubi ◽  
Sayer I. Al-azzam ◽  
Ahlam M. Al-buhairan
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Oxidative Dna Damage ◽  
Molecular Mechanisms ◽  
Interactive Effect ◽  
Future Research ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Bacterial Cell Death ◽  
Zones Of Inhibition

The mechanism of ciprofloxacin action involves interference with transcription and replication of bacterial DNA, which results in elevated oxidative stress, and bacterial cell death. Vorinostat was shown to induce oxidative DNA damage. In the current work, the possibility for interactive effect of vorinotat on ciprofloxacin-induced cytotoxicity against a number of reference bacteria was investigated. Standard bacterial strains were Escherichia coli ATCC 35218, Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC 9027, Staphylococcus epidermidis ATCC 12228, Acinetobacter baumannii ATCC 17978, Proteus mirabilis ATCC 12459, Klebsiella pneumoniae ATCC 13883, methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), and Streptococcus pneumoniae (ATCC 25923). The antibacterial activity of ciprofloxacin with or without pretreatment of bacterial cells by vorinostat was examined using disc diffusion procedure and determination of the minimum inhibitory concentration (MIC) and zones of inhibition of bacterial growth. All tested bacterial strains showed sensitivity to ciprofloxacin. When pretreated with vorinostat, significantly larger zones of inhibition and smaller MIC values were observed in all bacterial strains compared ciprofloxacin alone. As a conclusion, current results showed the possible agonistic properties for vorinostat when it is used together with ciprofloxacin. Future research will be focus on molecular mechanisms possible for such interactive effect.

Hemolysis, Platelet Aggregation and Antibacterial Activities of Human Antiphospholipid Antibody

2020 ◽  
Vol 18 (3) ◽  
pp. 268-274
Author(s):  
Farzaneh Ahmadi Shapoorabadi ◽  
Maryam Sadat Mirbagheri Firoozabad ◽  
Neda Habibi ◽  
Giti Emtiazi
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Transmission Electron Microscopy ◽  
Antiphospholipid Antibodies ◽  
Diffusion Method ◽  
Klebsiella Pneumonia ◽  
Antiphospholipid Antibody ◽  
Bacterial Membranes ◽  
Transmission Electron ◽  
And Staphylococcus Aureus

Background: Anti-phospholipid antibodies have the potential to become an alternative to conventional antibiotics for humans. The Antiphospholipid Syndrome (APS) is an autoimmune disease where the body’s defense system incorrectly reacts against its own phospholipids. APS is distinct through the existence of venous and arterial thromboses, frequently multiple and recurring fetal losses, commonly accompanied by moderate thrombocytopenia. Anti-phospholipid antibodies include lupus anti-coagulant, anti- cardiolipin, anti-beta 2 glycoprotein 1, and anti-prothrombin antibodies. Methods: In this study, the mechanism of action of Anti-phospholipid antibodies against Klebsiella pneumonia and Staphylococcus aureus was investigated in great detail using a unique combination of imaging and biophysical techniques. Antibacterial activity of antiphospholipid antibodies was detected by a diffusion method and the investigation of the complexity of antibody-antigen was done by spectroscopic examination, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) imaging. Results: There was a profound change in the bacteria treated with healthy and patient serum in the optical microscopic study. In all of the studied fields, bacterial treatment with patient serum immediately induced bacterial swelling and cumulative accumulation of the bacteria while no changes were observed in the healthy serum. Anti-bacterial activities of patient serum were detected on the plate. The result of this study showed that after platelet activation by thrombin and incubation with antiphospholipid antibodies, the platelet was aggregated. The transmission electron microscopy (TEM) image showed that the cell wall of Klebsiella pneumonia and Staphylococcus aureus incubated with antiphospholipid had a bizarre shape and antiphospholipid antibodies bound to bacterial membranes. Conclusion: The data indicated that antiphospholipid antibodies with hemolysis activities have an effect on Gram-positive and negative bacteria and these antibodies have the potential to become antibiotic for human.

scholarly journals Pse-T2, an Antimicrobial Peptide with High-Level, Broad-Spectrum Antimicrobial Potency and Skin Biocompatibility against Multidrug-ResistantPseudomonas aeruginosaInfection

2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Hee Kyoung Kang ◽  
Chang Ho Seo ◽  
Tudor Luchian ◽  
Yoonkyung Park
Keyword(s):  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Helical Structure ◽  
Multidrug Resistant ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Bacterial Membranes

ABSTRACTPseudin-2, isolated from the frogPseudis paradoxa, exhibits potent antibacterial activity but also cytotoxicity. In an effort to develop clinically applicable antimicrobial peptides (AMPs), we designed pseudin-2 analogs with Lys substitutions, resulting in elevated amphipathic α-helical structure and cationicity. In addition, truncated analogs of pseudin-2 and Lys-substituted peptides were synthesized to produce linear 18-residue amphipathic α-helices, which were further investigated for their mechanism and functions. These truncated analogs exhibited higher antimicrobial activity and lower cytotoxicity than pseudin-2. In particular, Pse-T2 showed marked pore formation, permeabilization of the outer/inner bacterial membranes, and DNA binding. Fluorescence spectroscopy and scanning electron microscopy showed that Pse-T2 kills bacterial cells by disrupting membrane integrity.In vivo, wounds infected with multidrug-resistant (MDR)Pseudomonas aeruginosahealed significantly faster when treated with Pse-T2 than did untreated wounds or wounds treated with ciprofloxacin. Moreover, Pse-T2 facilitated infected-wound closure by reducing inflammation through suppression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). These data suggest that the small antimicrobial peptide Pse-T2 could be useful for future development of therapeutic agents effective against MDR bacterial strains.

scholarly journals In vitro biological activity of liposomal-containing antimony trioxide

2021 ◽  
Vol 10 (11) ◽  
pp. e391101119755
Author(s):  
Altevir Rossato Viana ◽  
Angelita Bottega ◽  
Marissa Bolson Serafin ◽  
Bruno Salles ◽  
Rosmari Horner ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Lines ◽  
Ph Value ◽  
Culture Collection ◽  
Free Form ◽  
Antimony Trioxide ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Diphenyltetrazolium Bromide

Antimonials are used as chemotherapy for leishmaniasis, but have limited results due to their toxicity and broad resistance already acquired by the parasites. Nanotechnology offers an alternative to reduce these effects through the use of biocompatible nanocarriers, which can be vectorized to the target site. In addition, the redirection of molecules, already developed for the treatment of other pathologies, has the advantage of being already approved for therapy by regulatory agencies. The present study addresses the production of liposomal vesicles containing antimony trioxide (LC Sb2O3), as well as the evaluation of activity against tumor and bacterial cells. We produce liposomes in order of nanometric size, polydispersity index (PDI <0.3), pH value close to physiological (7.2), and zeta potential (anionic). Cytotoxicity was evaluated in 24 and 72 hours, in the HepG2, T98G, and U87MG tumor cell lines, by the method (3-4.5 dimethylthiazole-2.5 diphenyltetrazolium bromide) (MTT). The minimum inhibitory concentration (MIC) was tested on three bacterial strains (American Type Culture Collection – ATCC-Escherichia coli ATCC 35218, Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212) and mandatory (Staphylococcus aureus and Klebsiella pneumoniae). The liposomes were more cytotoxic than Sb2O3 in the free form, for all tested cell lines. This effect was stronger after 72 hours incubation. Antimony trioxide in both free and liposomal forms showed low antibacterial activity. Based on our results, we suggest that liposomes containing antimony trioxide have the potential for the repositioning of drugs addressing anticancer therapy.

scholarly journals Magnetically controlled microorganisms for the biological industrial wastewater treatment

2020 ◽  
Vol 10 (2) ◽  
pp. 185-200
Author(s):  
Irina V. Vladimtseva ◽  
Irina V. Mogilevskaya ◽  
Olga V. Kolotova ◽  
Valery E. Drevin
Keyword(s):  
Electromagnetic Field ◽  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Nutrient Media ◽  
Industrial Wastewater Treatment ◽  
Magnetic Carriers ◽  
Effective Technology ◽  
Biomass Increase

Microorganisms immobilized on magnetic carriers are used in biotechnology to increase efficiency and simplify work with microbial cells. The aim of this study was to obtain magnetically controlled immobilized forms of the environmentally significant microorganisms and to study the possibility of their cultivation with artificial nutrient media. Two bacterial strains, identified as the genus Bacillus, were used as the research object: B. subtilis ВГТУ05 and B. species ВГТУ06, promising for biological industrial wastewater treatment. The work carried out the immobilization of strains in magnetic alginate carriers. Established the bacterial cells’ immobilization did not affect their vitality. The optimal parameters of the electromagnetic field strength for growing strains in liquid nutrient media were selected. Shown the bacterial destructive strains immobilized into magnetic carriers gave the biomass increase of 24.3–25.0% during the cultivation in the electromagnetic field. The results could be used to develop the effective technology for local biological industrial wastewater treatment.

scholarly journals A novel cell permeability assay for macromolecules

2020 ◽  
Author(s):  
Yensi Alejandra Flores Bueso ◽  
Sidney Peter Walker ◽  
Mark Tangney
Keyword(s):  
Mammalian Cells ◽  
Binding Activity ◽  
Cell Permeability ◽  
Bacterial Cells ◽  
New Host ◽  
Bacterial Membranes ◽  
Specific Permeability ◽  
Biotin Binding ◽  
Permeability Assay ◽  
Formalin Fixed

Abstract Background Many cell permeabilisation methods to mediate internalisation of various molecules to mammalian or bacterial cells have been developed. However, no size-specific permeability assay suitable for all cells exists. Results We report for the first time, use of intrinsically biotinylated cell components as the target for reporter molecules for assessing permeabilisation. Due to its well-described biotin binding activity, we developed an assay using Streptavidin (SAv) as a molecular weight marker for assessing eukaryotic and prokaryotic cell internalisation, using flow cytometry as a readout. This concept was tested here in the development of host DNA depletion strategies for microbiome analysis of formalin-fixed samples. This strategy requires differential cell permeabilisation, where mammalian cells but not bacterial cells are permeabilised, and are subsequently treated with a nuclease. Here, the internalisation of a SAv-conjugate was used as a reference for nucleases of similar dimensions. With this assay, it was possible to demonstrate that FF does not generate pores which allow the introduction of 60 KDa molecules in both mammalian and bacterial membranes/envelopes. Among surfactants tested, Saponin showed the best selectivity for mammalian cell permeabilisation, which, when coupled with Benzonase nuclease, provided the best results for host DNA depletion, representing a new host depletion strategy for formalin fixed samples. Conclusion The assay presented provides researchers with a sensitive and accessible tool for discerning membrane/cell envelop permeability for different size macromolecules.

scholarly journals The strongest resistance of Staphylococcus aureus to erythromycin is caused by decreasing uptake of the antibiotic into the cells

2012 ◽  
Vol 17 (4) ◽  
Author(s):  
Elżbieta Piątkowska ◽  
Jerzy Piątkowski ◽  
Anna Przondo-Mordarska
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Resistance ◽  
Permeability Barrier ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Erythromycin Resistance ◽  
Genetic Investigation ◽  
Efflux Mechanism ◽  
Resistant Strains ◽  
Very High

AbstractThe consequence of excessive use of macrolides is a high occurrence of mechanisms responsible for resistance to these drugs. Of 97 erythromycin-resistant bacterial strains gathered in the Wrocław area in Poland, 60% exhibited very high resistance, and those with the inducible MLSB (macrolide-lincosamide-streptogramin B) resistance phenotype predominated. Direct genetic investigation revealed that the erm genes coding for ribosomal methylases are the most frequently occurring erythromycin resistance-determining genes. No genetic resistance determinant was detected in 13% of the erythromycin-resistant strains. The efflux mechanism occurs in strains isolated from the nasopharyngeal cavity twice as often as in those isolated from other material, where the mechanism connected with target site modification predominates. Measurements of radiolabelled antibiotic accumulation inside bacterial cells revealed that in highly resistant strains (MIC > 1024 μg/ml), an important factor responsible for the resistance is the permeability barrier at the cell wall level. This would be a hitherto unknown mechanism of resistance to erythromycin in Staphylococcus aureus.

Sign in / Sign up

Export Citation Format

Share Document