scholarly journals Исследование фотокаталитической антимикробной активности нанокомпозитов на основе TiO-=SUB=-2-=/SUB=--Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- при воздействии светодиодного излучения (405 nm) на стафилококки

2021 ◽  
Vol 129 (6) ◽  
pp. 736
Author(s):  
А.В. Светлакова ◽  
М. Sanchez Mendez ◽  
Е.С. Тучина ◽  
А.Н. Ходан ◽  
М. Traore ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Photocatalytic Activity ◽  
Aluminum Oxide ◽  
Heterogeneous Photocatalysis ◽  
Pathogenic Microorganisms ◽  
Tio2 Content ◽  
Antibacterial Efficiency ◽  
Antimicrobial Coating

The photocatalytic activity of nanocomposites based on theta-modification of aluminum oxide Al2O3 with different TiO2 content for heterogeneous photocatalysis and biodegradation of pathogenic microorganisms under the action of LED radiation with a wavelength of 405 nm has been studied. It was found that all the investigated nanocomposites have photocatalytic activity. The maximum antibacterial efficiency of composites with a TiO2 content of 8 wt% (reduction of CFU of Staphylococcus aureus 209 P to 86%), which allows us to recommend this nanomaterial as a promising antimicrobial coating.

scholarly journals Zirconium-Doped Chromium IV Oxide Nanocomposites: Synthesis, Characterization, and Photocatalysis towards the Degradation of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 117
Author(s):  
Zahir Muhammad ◽  
Farman Ali ◽  
Muhammad Sajjad ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Solid State ◽  
Room Temperature ◽  
Organic Dyes ◽  
Uv Light ◽  
Heterogeneous Photocatalysis ◽  
Ft Ir ◽  
Complete Mineralization

Degradation of organic dyes and their byproducts by heterogeneous photocatalysts is an essential process, as these dyes can be potentially discharged in wastewater and threaten aquatic and xerophyte life. Therefore, their complete mineralization into nontoxic components (water and salt) is necessary through the process of heterogeneous photocatalysis. In this study, Zr/CrO2 (Zirconium-doped chromium IV oxide) nanocomposite-based photocatalysts with different compositions (1, 3, 5, 7 & 9 wt.%) were prepared by an environmentally friendly, solid-state reaction at room temperature. The as-prepared samples were calcined under air at 450 °C in a furnace for a specific period of time. The synthesis of Zr/CrO2 photocatalysts was confirmed by various techniques, including XRD, SEM, EDX, FT-IR, UV-Vis, and BET. The photocatalytic properties of all samples were tested towards the degradation of methylene blue and methyl orange organic dyes under UV light. The results revealed a concentration-dependent photocatalytic activity of photocatalysts, which increased the amount of dopant (up to 5 wt.%). However, the degradation efficiency of the catalysts decreased upon further increasing the amount of dopant due to the recombination of holes and photoexcited electrons.

scholarly journals Pseudomonas aeruginosa and Staphylococcus aureus virulence factors as biomarkers of infection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Artur J. Sabat ◽  
Daniele Pantano ◽  
Viktoria Akkerboom ◽  
Erik Bathoorn ◽  
Alexander W. Friedrich
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Clinical Status ◽  
Clinical Samples ◽  
Pathogenic Microorganisms ◽  
Bacterial Identification ◽  
Accurate Identification ◽  
Culture Independent ◽  
And Staphylococcus Aureus

Abstract The gold standard for the diagnosis of bacterial infections in clinical samples is based on culture tests that are time-consuming and labor-intense. For these reasons, an extraordinary effort has been made to identify biomarkers as the tools for sensitive, rapid and accurate identification of pathogenic microorganisms. Moreover, biomarkers have been tested to distinguish colonization from infection, monitor disease progression, determine the clinical status of patients or predict clinical outcomes. This mini-review describes Pseudomonas aeruginosa and Staphylococcus aureus biomarkers, which contribute to pathogenesis and have been used in culture-independent bacterial identification directly from patient samples.

scholarly journals Systems developed for application as self-cleaning surfaces and/or antimicrobial properties: a short review on materials and production methods

Cerâmica ◽  
2019 ◽  
Vol 65 (375) ◽  
pp. 477-484 ◽  
Author(s):  
M. P. Madeira ◽  
A. O. Lobo ◽  
B. C. Viana ◽  
E. C. Silva Filho ◽  
J. A. Osajima
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Photocatalytic Activity ◽  
Medical Devices ◽  
Spin Coating ◽  
Antimicrobial Properties ◽  
Short Review ◽  
Dip Coating ◽  
Production Methods ◽  
Self Cleaning

Abstract Herein we present a short review of different materials and techniques that have been used for the production of surfaces with self-cleaning and/or antimicrobial properties. From this, it was verified that titanium dioxide was the most frequently used compound to obtain surfaces with these properties; however, other materials such as silica, zinc and silver have also been used for this purpose. The spin-coating and dip-coating techniques were the most used techniques, and the bacteria Staphylococcus aureus and Escherichia coli were the most used in the antimicrobial assays. The analyzed studies showed that it is possible to obtain surfaces with both self-cleaning and/or antimicrobial properties, as well as with photocatalytic activity. Regarding possible applications, it is possible to highlight the interest in the production of glass and medical devices with self-cleaning and/or antimicrobial action.

scholarly journals Piperine Plays an Anti-Inflammatory Role inStaphylococcus aureusEndometritis by Inhibiting Activation of NF-κB and MAPK Pathways in Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Wen-jun Zhai ◽  
Zhen-biao Zhang ◽  
Nian-nian Xu ◽  
Ying-fang Guo ◽  
Changwei Qiu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Inflammatory Response ◽  
Mouse Model ◽  
Biological Activities ◽  
Dependent Manner ◽  
Pathogenic Microorganisms ◽  
Histopathological Changes ◽  
Natural Medicine ◽  
Anti Inflammatory ◽  
Dose Dependent

Endometritis is commonly caused by pathogenic microorganisms, includingStaphylococcus aureus(S. aureus). Piperine, which is a natural medicine, has shown a variety of biological activities. To explore the effect and mechanism of piperine onS. aureusendometritis, a mouse model ofS. aureusendometritis was successfully established in the present study. Histopathological changes were observed with H&E staining, cytokines were analyzed by ELISA, mRNA was analyzed by qPCR, and proteins were detected by western blot. The results showed that piperine could significantly alleviate inflammatory injury inS. aureusendometritis. The qPCR and ELISA results showed that piperine effectively reduced theS. aureus-induced overexpression of TNF-α, IL-1β, and IL-6 but increased the expression of IL-10. TheS. aureus-induced inflammation was related to TLR-2 and TLR-4 because the results showed that their expression was increased inS. aureusinfection but then decreased with piperine treatment. To further confirm that piperine caused an anti-inflammatory response by targeting NF-κB and MAPKs, the expression of I-κB, p65, p38, ERK, and JNK was measured. The phosphorylation of I-κB, p65, p38, ERK, and JNK was inhibited by piperine in a dose-dependent manner. All of the results indicated that piperine may be a potential anti-inflammatory drug both in endometritis and in otherS. aureus-induced diseases.

scholarly journals Photocatalytic effect of led radiation (405 nm) and new Al2O3 3D-nanocomposites on the growth of Staphylococcus aureus

2021 ◽  
Vol 21 (2) ◽  
pp. 185-189
Author(s):  
Anna V. Svetlakova ◽  
◽  
Elena S. Tuchina ◽  
Keyword(s):  
Staphylococcus Aureus ◽  
Aluminum Oxide ◽  
Bacterial Growth ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Semiconductor Material ◽  
Photocatalytic Properties ◽  
Photocatalytic Effect ◽  
Antibiotic Drugs ◽  
Progressive Growth

The progressive growth of bacterial resistance to antibiotic drugs requires the creation of highly efficient nanomaterials. Aluminum oxide is a stable non-toxic semiconductor material; however, the photocatalytic properties of its modifications in relation to microorganisms are not well understood. In this study, we used new 3D composites of aluminum oxyhydroxide (Al2O3 × nH2O) in three modifications (γ, α and θ), which are a mesh of 150 nm nanofibrils. The assessment of the photocatalytic antibacterial properties of the composites was carried out on the museum strain S. aureus 209 P. It was shown that, in combination with violet LED radiation (405 nm, 17 mW/cm2), the composites under study significantly suppress bacterial growth (from 65 to 89%), with the sample containing γ-Al2O3 showing the best result.

scholarly journals EXPERIMENTAL STUDY OF THE PHENOMENON OF MICROORGANISM-ASSOCIATED CRYSTALLOGENESIS

2021 ◽  
Vol 11 (3) ◽  
pp. 20-21
Author(s):  
Andrew Martusevich ◽  
Ivan Bocharin ◽  
Maxim Guryanov ◽  
Alexey Kochkurov ◽  
Elena Kochkurova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Experimental Study ◽  
Sodium Chloride ◽  
Functional State ◽  
Crystal Formation ◽  
Pathogenic Microorganisms ◽  
Salt Solutions ◽  
E Coli ◽  
And Staphylococcus Aureus

The aim of the study was to clarify the character of the initiatory activity of pathogenic and nonpathogenic microorganisms in regard to salt solutions. We selected colonies of two microorganisms: Escherichia coli (E. coli) and Staphylococcus aureus (St. aureus) [106 , 108 , 1010, 1012, 1014, 1016, 1018 and 1020 CFU/ml of solution]. A 10% solution of sodium chloride was used as the initiated substance, which made it possible to perform a tezigraphic test. On the basis of model experiments with colonies of some pathogenic and non-pathogenic microorganisms, a new phenomenon was confirmed — microbial initiation of crystal formation (the phenomenon of microorganismassociated crystallogenesis). This phenomenon is universal for microagents, but it also has specific features imposed by the species of the microorganism and its current functional state.

scholarly journals Antagonistic action of Lactobacillus spp. against Staphylococcus aureus in cheese from Mompox - Colombia

2015 ◽  
Vol 68 (2) ◽  
pp. 7721-7727
Author(s):  
Piedad M. Montero Castillo ◽  
Antonio Díaz Caballero ◽  
Marlene Durán Lengua
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Antagonistic Activity ◽  
Food Preservation ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Antagonistic Action ◽  
As Species ◽  
Chemical Products

In the food industry, food preservation techniques that do not use chemical products are becoming more common. Therefore, the aim of this research was to evaluate the antagonistic activity (antibiosis) of lactic-acid bacterial strains against pathogenic microorganisms. Lactic-acid bacterial strains were isolated from layered cheese and a commercial product (yogurt); and the same was done with pathogenic bacteria solely from layered cheese. The lactic-acid bacterial strains were identified as species from the Lactobacilli family, while the pathogenic bacteria from layered cheese were identified as Micrococcaceae family species (Staphylococcus aureus). Subsequently, in the same culture medium, bacteria of each species were sowed in order to determine the inhibitory activity ability of the Lactic Acid Bacteria (BAL) As a result, the highly antagonistic activity of the Lactobacilli (inhibition halos were larger than 0.5 centimeters in diameter) against isolated pathogenic microorganisms was demonstrated.

scholarly journals Application of Median Lethal Concentration (LC50) of Pathogenic Microorganisms and Their Antigens in Vaccine Development

2020 ◽  
Author(s):  
Saganuwan Alhaji Saganuwan
Keyword(s):  
Staphylococcus Aureus ◽  
Disease Virus ◽  
Vaccine Development ◽  
Hepatitis A Virus ◽  
Lethal Dose ◽  
Vaccine Dose ◽  
Pathogenic Microorganisms ◽  
Bacterial Colony ◽  
Mouth Disease Virus

Abstract Objective: Lack of ideal mathematical models to qualify and quantify both pathogenicity, and virulence is a dreadful setback in development of new antimicrobials and vaccines against resistance pathogenic microorganisms. Hence, the modified arithmetical formula of Reed and Muench has been integrated with other formulas and used to determine bacterial colony forming unit/ viral concentration, virulence and immunogenicity. Results: Microorganisms’antigens tested are Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa in mice and rat, Edwardsiella ictaluri, Aeromonas hydrophila, Aeromonas veronii in fish, New Castle Disease virus in chicken, Sheep Pox Virus, Foot-and-Mouth Disease Virus and Hepatitis A virus in vitro, respectively. The LC50s for the pathogens using different routes of administrations are 1.93 x 103(sheep poxvirus) and 1.75 x 1010 for Staphylococcus aureus (ATCC29213) in rat respectively. Titer index (TI) equals N log10 LC50 and provides protection against lethal dose in graded fashion which translates to protection index. N is the number of vaccine dose that could neutralize the LC50. Hence, parasite inoculum of 103 to 1011may be used as basis for determination of LC50 and median bacterial concentrations (BC50).Pathogenic dose for immune stimulation should be sought at concentration about LC10.

scholarly journals Novel Pt-Ag3PO4/CdS/Chitosan Nanocomposite with Enhanced Photocatalytic and Biological Activities

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2320
Author(s):  
Mahsa Kiani ◽  
Mojtaba Bagherzadeh ◽  
Reyhaneh Kaveh ◽  
Navid Rabiee ◽  
Yousef Fatahi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Photocatalytic Activity ◽  
Klebsiella Pneumoniae ◽  
Visible Light ◽  
Salmonella Typhimurium ◽  
Bacillus Cereus ◽  
Visible Light Irradiation ◽  
Light Irradiation

Decorating photocatalysts with noble metal nanoparticles (e.g., Pt) often increases the catalysts’ photocatalytic activity and biomedical properties. Here, a simple and inexpensive method has been developed to prepare a Pt-Ag3PO4/CdS/chitosan composite, which was characterized and used for the visible light-induced photocatalytic and antibacterial studies. This synthesized composite showed superior photocatalytic activity for methylene blue degradation as a hazardous pollutant (the maximum dye degradation was observed in 90 min of treatment) and killing of Gram positive bacterial (Staphylococcus aureus and Bacillus cereus) as well as Gram negative bacteria (Klebsiella pneumoniae, Salmonella typhimurium, Escherichia coli, and Pseudomonas aeruginosa) under visible light irradiation. The antibacterial activity of CdS, CdS/Ag3PO4, and Pt-Ag3PO4/CdS/chitosan against E. coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus cereus showed the zone of inhibition (mm) under visible light and under dark conditions at a concentration of 20 µg mL−1. Furthermore, the cell viability of the CdS/chitosan, Ag3PO4, Ag3PO4/CdS/chitosan, and Pt-Ag3PO4/CdS/chitosan were investigated on the human embryonic kidney 293 cells (HEK-293), Henrietta Lacks (HeLa), human liver cancer cell line (HepG2), and pheochromocytoma (PC12) cell lines. In addition, the results indicated that the photodegradation rate for Pt-Ag3PO4/CdS/chitosan is 3.53 times higher than that of CdS and 1.73 times higher than that of the CdS/Ag3PO4 composite. Moreover, Pt-Ag3PO4/CdS/chitosan with an optimal amount of CdS killed large areas of different bacteria and different cells separately in a shorter time period under visible-light irradiation, which shows significantly higher efficiency than pure CdS and other CdS/Ag3PO4 composites. The superb performances of this composite are attributed to its privileged properties, such as retarded recombination of photoinduced electron/hole pairs and a large specific surface area, making Pt-Ag3PO4/CdS/chitosan a valuable composite that can be deployed for a range of important applications, such as visible light-induced photocatalysis and antibacterial activity.

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