Study Of Antibacterial Properties Research Articles

Lanthanide furoate complexes as promising systems with double effects – From suppression of mycobacteria to potential bioimaging

Several ternary complexes of rare earth ions (Gd3+, Eu3+, Sm3+) with 3-furoic (H3fur) / 5-nitro-2-furoic (Hnfur) acids and 1,10-phenanthroline (phen) have been synthesized. According to the X-ray data the resulting complexes can be divided into two groups − heterocarboxylate [Ln2(3fur)4(OAc)2(phen)2]·L and homocarboxylate complexes [Ln2(nfur)6(phen)2]·L (LnIII = Gd (1, 2), Eu (3, 4), Sm (5, 6, 7); L = 4EtOH (1–4), 4MeOH (5), H2O (7)). The stability of the complexes 1–6 in solutions was studied by recording electronic absorption spectra for two days. Optical properties of the complexes 1–6 were studied by recording absorption, excitation and luminescence spectra. The study of antibacterial properties 1–7 showed high activity of complexes in vitro against non-pathogenic Mycolicibacterium smegmatis. For the most active 3, antibacterial activity against the reference strain Mycobacterium tuberculosis H37Rv was determined (minimum inhibitory concentration (MIC) up to 12.5 μg/mL)..

Hybrid Molecules of Azithromycin with Chloramphenicol and Metronidazole: Synthesis and Study of Antibacterial Properties.

The sustained rise of antimicrobial resistance (AMR) causes a strong need to develop new antibacterial agents. One of the methods for addressing the problem of antibiotic resistance is through the design of hybrid antibiotics. In this work, we proposed a synthetic route for the conjugation of an azithromycin derivative with chloramphenicol and metronidazole hemisuccinates and synthesized two series of new hybrid molecules 4a-g and 5a-g. While a conjugation did not result in tangible synergy for wild-type bacterial strains, new compounds were able to overcome AMR associated with the inducible expression of the ermC gene on a model E. coli strain resistant to macrolide antibiotics. The newly developed hybrids demonstrated a tendency to induce premature ribosome stalling, which might be crucial since they will not induce a macrolide-resistant phenotype in a number of pathogenic bacterial strains. In summary, the designed structures are considered as a promising direction for the further development of hybrid molecules that can effectively circumvent AMR mechanisms to macrolide antibiotics.

Aniline derivatives containing a cage monoterpenoid fragment at the nitrogen atom: synthesis and study of antibacterial properties

Aniline derivatives containing a cage monoterpenoid fragment at the nitrogen atom: synthesis and study of antibacterial properties

Investigation of Antibacterial Properties of Corrosion-Resistant 316L Steel Alloyed with 0.2 wt.% and 0.5 wt.% Ag.

The article is devoted to the study of melted ingots, plates rolled from them, and the resulting spherical powder made of corrosion-resistant 316L steel with the addition of 0.2 wt.% and 0.5 wt.% Ag. The study of antibacterial properties, microstructure, and distribution of silver concentrations, as well as qualitative analysis of silver content was carried out. The optimal mode of homogenization annealing of the ingot was 1050 °C for 9 h, which leads to the formation of an austenitic structure. It is shown that the addition of a small amount of silver does not affect the formation of the austenitic structure and silver is distributed evenly throughout the volume of the ingot. The austenitic structure also prevails in the plates after rolling. Silver is distributed evenly throughout the entire volume of the plate. It is noted that the addition of 0.2 wt.% Ag does not affect the strength, elongation, and microhardness of steel, and the addition of 0.5 wt.% Ag does not significantly reduce the strength of steel, however, all samples meet the mechanical characteristics according to the ASTM A240 standard. The qualitative chemical composition of samples made of corrosion-resistant steels was confirmed by X-ray fluorescence analysis methods. By the method of energy-dispersion analysis, the presence of a uniform distribution of silver over the entire volume of the powder particle was determined. The particles have a spherical shape with a minimum number of defects. The study of the antibacterial activity of plates and powder shows the presence of a clear antibacterial effect (bacteria of the genus Xanthomonas campestris, Erwinia carotovora, Pseudomonas marginalis, Clavibacter michiganensis) in samples No. 2 and No. 3 with the addition of 0.2 wt.% and 0.5 wt.% Ag.

Antibacterial polymeric micelles based on kojic acid/acrylic acid/chitosan

In the present study, antibacterial micelles based on poly [5-(benzyloxy)-4-oxo-4H-pyran-2-yl] methyl acrylate/polyacrylic acid/chitosan(PBOPMA-PAA-Cs) terpolymer with suspended kojic acid groups was synthesized. For this purpose, first, protected kojic acid (BOP) was prepared by reaction of 5-hydroxy-2-hydroxymethyl-4 H-pyran-4-one with benzyl chloride. Subsequently, [5-(benzyloxy)-4-oxo-4H-pyran-2-yl] methyl acrylate(BOPMA) was prepared by esterification reaction between protected kojic acid hydroxyl groups and carboxylic groups related to acrylic acid. The initiator, [5-(benzyloxy)-4-oxo-4H-pyran-2-yl] methyl-2-bromo-2-methylpropanoate (BOPBr), was synthesized via acyl nucleophilic substitution. Polymerization of BOPMA by ATRP polymerization using initiator (BOPBr) was performed. The PBOPMA-PAA copolymer was prepared by free radical polymerization. In the final step, PBOPMA-PAA-Cs terpolymer was prepared by esterification reaction of the N-phthaloylated chitosan hydroxyl group with the carboxylic acid groups of the PBOPMA-PAA copolymer. Micelles with a size of 20 ± 5 nm were prepared from amphiphilic terpolymers and their morphology and size were evaluated by TEM and DLS, respectively. The structure, thermal stability, and morphology of synthesized compounds were confirmed by FT-IR, 1H-NMR, TGA, and SEM. Furthermore, in the study of antibacterial properties against gram-positive and negative bacteria, PBPMA, PBPMA-PAA, and PBPMA-PAA-Cs behaved differently, however, all three had good antibacterial properties compared to gentamicin and ampicillin.

A novel SiO2/Polyetherimide (PEI) Composite Synthesized by Sol‐Gel Route: Characterization and Antibacterial Activity

AbstractPolyetherimide (PEI), an amorphous thermoplastic material, is a promising candidate for wide applications due to its high heat stability and its biocompatibility in human tissues. In the present paper, PEI (4 wt%) is added to SiO2 inorganic matrix in order to obtain a novel composite biomaterial through sol‐gel route. Structural characterization by means of Fourier Transform Infrared Spectroscopy (FTIR) confirmed, through hydrogen bond interactions, the presence of both organic and inorganic components in the structure. Concerning the compatibility in the biological systems, a study of antibacterial properties is carried out, analyzing the effect of SiO2/PEI composite on Escherichia coli (gram‐negative) and Enterococcus faecalis (gram‐positive).

The Study of Antibacterial Properties of Anbarnasara Smoke on Multi-Drug Resistant Bacteria Isolated From Urinary Infection in Pregnant Women

Background: Using smoke from burning donkey dung has been popular in the treatment of many diseases in Iran. Objective: This study aimed to investigating the antimicrobial properties of donkey dung smoke on multi-drug resistant (MDR) bacteria isolated from urinary infection. Materials and Methods: First, 300 and 200 urine samples were collected from pregnant and non-pregnant women in Isfahan, Iran. Then in each group, 100 bacterial isolates including Escherichia coli, Klebsiella pneumonia, Proteus vulgaris, Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus saprophyticus were isolated. Antibiotic resistant protocol was determined by antibiogram test. Donkey dung was sterilized, disintegrated, and heated. The smokes were concentrated in n-hexane solvent (65%) and were collected after evaporation of the solvent. Finally, the antibacterial activities of the concentrations of 0.25, 0.5 and 1 mg/mL of the smokes were detected using disk diffusion and macrodilution methods. Results: The most abundant MDR isolates causing urinary infections in pregnant and non-pregnant women was Escherichia coli. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of donkey dung smoke on MDR isolates from pregnant women were 0.25 mg/mL and 0.5 mg/mL, respectively. In the case of MDR isolates in non-pregnant women, the MIC of the smoke on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was 0.25 mg/mL, and the MBC on these isolates was 0.5 mg/mL. Conclusion: The smokes from donkey dung investigated in the present study have suitable potentials for controlling the infections after In vivo analysis.

THE EFFECT OF ESSENTIAL OILS ON MICROORGANISMS CAUSING CARIES AND PERIODONTITIS

The oral cavity contains a large number of bacteria, some of which are involved in the development of caries and periodontitis (S. mutans, S. sobrinus, Lactobacilli spp, P. intermedia, P. gingivalis, and T. forythus). The disadvantages of existing antiseptics used in dentistry necessitate the study of antibacterial properties of herbal medicines, and, in particular, of essential oils. The aim of this review is to provide the analysis of literature sources from PubMed and Google Scholar databases related to the effects of essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components on cariogenic and periodontopathic microflora. It was found out that the most in vitro studies evaluated the effects of essential oils or isolated compounds (eugenol, menthol, thymol, carvacrol, eucalyptol, and terpinene-4-ol) on S. mutans, which is considered to be the most cariogenic of oral streptococci, and the researchers limited to defining the susceptibility of the microorganism and effects on biofilm formation. Only in a few studies, the effects of essential oils on the virulence factors of oral pathogens, in particular glycosyl transferase, are represented. Clinical trials of essential oils, their components and combinations confirm the therapeutic potential of these agents in vivo, but raise the question of their effectiveness, taking into account the short-term action, which does not exceed the potency of chlorhexidine. Essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components should be used for treating caries and periodontitis. They are also promising when used as agents of the oral care products, preservatives of the dental medicinal forms, and as remedies for halitosis. With a rational prescription, essential oils can be useful in improving the quality of dental treatment and preventive procedures.

Green Synthesis of Zinc Oxide Nanoparticles and their Antibacterial Properties using Plant Extract of Aristolochia elegans

Present paper deals with the synthesis of zinc oxide nanoparticles (ZnONPs) using leaf extract of Aristolochia elegans and study of antibacterial property for some human bacterial pathogens. The ZnONPs synthesized were characterized using UV-Vis, FT-IR, XRD, EDX, TEM and SEM techniques. The synthesized ZnONP having a crystallite size of 20.1 nm exhibited a distinct absorption peak maxima at 358 nm. The ZnONPs synthesized using the extract of A. elegans have shown antibacterial activity against M. luteus, S. aureus (Gram-positive), E. coli and P. aeruginosa (Gram-negative).

In- Vitro Study of Antibacterial Properties and Phytochemical Contents of Coriander Seeds Against Five Bacteria.

In- Vitro Study of Antibacterial Properties and Phytochemical Contents of Coriander Seeds Against Five Bacteria.

Study on the Properties of Composites of Carbon Quantum Dots and Zinc Oxide

In this paper, ZnO and carbon quantum dots (CQDs) were grafted by ultrasonic method to prepare ZnO/CQDs composites with good performance, through the study of antibacterial properties, we can find that the antibacterial activity against Gram-negative bacteria (Escherichia coli) is better than the Gram-positive bacteria (Staphylococcus aureus), and it has low cytotoxicity, the antibacterial activity can be contributed to the generation of hydrogen peroxide (H2O2) from their surfaces.

Study of antibacterial properties of honey to methycilin resistant Staphylococcus

For publishing this article, two important ideas were indicated: the first one is the necessity of scientific research to establish antibacterial properties in those substances that can replace antibiotics in the fight against antibiotic resistant microorganisms; the second is to expand the possibilities for using a national Ukrainian product, such as honey. Ukraine is one of the important exporters of honey in the EU. This honey may have unique physical and chemical properties that will characterize its therapeutic effect. In other countries, these issues are actively studied by scientists, which provide special healing brands to certain its species. These issues are not well study in Ukraine. The aim of present study was to an experimental study of the use of antibacterial properties of honey in relation to methicillin-resistant Staphylococcus spp. Materials for research were isolates of methicillin-resistant Staphylococcus spp. (MRSS) and samples of natural honey that were obtained from apiaries of the Odessa region. The standard methods of isolation Staphylococcus spp and methods determining the quality of honey were used. Qualitative indicators of honey included organoleptic studies, moisture and acidity, proline content. Determination of antibacterial properties of honey was studied in dilution it in distilled water in proportions 1:1, 1:2, 2:1 and 3:1 with following plating in nutrient agar wells on Petri dishes. It has been experimentally established that honey may be an excellent remedy against MRSS, but not all honey has the same antimicrobial activity. It has been established that the antibacterial properties of honey in relation to MRSS are influenced by the physical and chemical composition, namely the content of proline. It has been experimentally established that most types of investigated honey samples with high qualitative indices exhibited antibacterial action against antibiotic-resistant isolates of Staphylococcus spp., With higher levels of antibacterial activity showing those honey samples that had a higher proline content of more than 350 mg/kg. It was established that the antibacterial action of honey against antibiotic resistant isolates of Staphylococcus spp. It is better manifested in more concentrated solutions – when diluted in the ratio of honey / solvent as 2:1 and 3:1 (growth retardation zones from 34 mm to 58 mm) compared to solutions of honey diluted in proportions 1:1 and 1:2 (growth retardation zones from 10 mm to 15 mm).

THE STUDY OF NANOSTRUCTURED ANATASE COATINGS ON THE SURFACE OF RUTILE

Nanosized titanium dioxide allows solving complex engineering problems. One of such tasks is the creation of materials and coatings that reduce the likelihood of nosocomial infections on the surface of orthopedic structures including implant systems. The paper presents the results of the Raman spectroscopy, X-ray diffraction analysis and scanning electron microscopy of anatase ceramic coatings deposited by sol-gel technology on a sintered material based on a nanosized titanium dioxide powder (rutile modification). The resulting coating has a complex layered structure, which is almost completely represented by titanium dioxide in the anatase phase according to the Raman spectroscopy data. The simultaneous existence of both phases in the coating was recorded. The identification of rutile on diffractograms seems to be due to the fact that modified peak intensity rutile is mainly formed during the first stages of coating application on the polycrystalline rutile surface. The fact that non-stoichiometric phases also present in the diffractograms suggests that coating phase composition is not the same in thickness and is represented by a gradual layerwise transition from rutile to anatase. The coating thickness is 60 ± 15 μm. The coating is represented by lamellar blocks of various sizes. The thickness of a single plate in the coating is 60–80 nm. The developed technique makes it possible to apply the anatase coating not only on samples of titanium dioxide ceramics but also on the surface of titanium implants with the preliminary formation of a titanium dioxide layer in the form of rutile on the metal surface. Experiments on the study of antibacterial properties and morphological characteristics of bone tissue in contact with the implant were carried out at the Department of Prosthetic Dentistry at the PSMU.

Strategies for penicillin V dendronization with cationic carbosilane dendrons and study of antibacterial properties

Strategies to synthesize a cationic carbosilane dendron containing the antibiotic penicillin V potassium salt (PenVK) at the focal point are discussed. The preparation of such a compound requires the use of systems with no donor atoms such as N or S in their framework, because their presence favours the rupture of the penicillin β-lactam ring. The antibacterial activity of the new dendron containing ammonium groups, at the periphery, and the PenV moiety, at the focal point, against gram-positive Staphylococcus aureus strains was evaluated. These results were compared with those obtained for free PenVK, a related cationic dendron without a penicillin moiety at the focal point, and also compared with an equimolar mixture of this last dendron with free PenV. The data obtained indicate that, on one hand, the conjugation or interaction of PenV with cationic dendrons reduces its activity in comparison with free PenVK. On the other hand, the penicillin dendron is able to release the antibiotic in the presence of esterease, due to the breaking of the ester bond in this derivative.

Effect of doping on structural and optical properties of ZnO nanoparticles: study of antibacterial properties

Abstract Sol-gel method was successfully used for synthesis of ZnO nanoparticles doped with 10 % Mg or Cu. The structure, morphology and optical properties of the prepared nanoparticles were studied as a function of doping content. The synthesized ZnO:(Mg/Cu) samples were characterized using XRD, TEM, FTIR and UV-Vis spectroscopy techniques. The samples show hexagonal wurtzite structure, and the phase segregation takes place for Cu doping. Optical studies revealed that Mg doping increases the energy band gap while Cu incorporation results in decrease of the band gap. The antibacterial activities of the nanoparticles were tested against Escherichia coli (Gram negative bacteria) cultures. It was found that both pure and doped ZnO nanosuspensions show good antibacterial activity which increases with copper doping, and slightly decreases with adding Mg.

Novel Copper (Cu) Loaded Core–Shell Silica Nanoparticles with Improved Cu Bioavailability: Synthesis, Characterization and Study of Antibacterial Properties

We report synthesis of a novel core-shell silica based antimicrobial nanoparticles where the silica shell has been engineered to accommodate copper (Cu). Synthesis of the core-shell Cu-silica nanoparticle (C-S CuSiO2NP) involves preparation of base-hydrolyzed Stöber silica "seed" particles first, followed by the acid-catalyzed seeded growth of the Cu-silica shell layer around the core. The Scanning Electron Microscopy (SEM) and the Transmission Electron Microscopy (TEM) measured the seed particle size to be -380 nm and the shell thickness to be -35 nm. The SEM particle characterization confirms formation of highly monodispersed particles with smooth surface morphology. Characterization of particle size distribution in solution by Dynamic Light Scattering (DLS) technique was fairly consistent with the electron microscopy results. Loading of Cu to nanoparticles was confirmed by the SEM-Energy Dispersive X-Ray Spectroscopy (EDS) and Atomic Absorption Spectroscopy (AAS). The Cu loading was estimated to be 0.098 microg of metallic copper per mg of C-S CuSiO2NP material by the AAS technique. Antibacterial efficacy of C-S CuSiO2NP was evaluated against E. coli and B. subtilis using Cu hydroxide ("Insoluble" Cu compound, sub-micron size particles) as positive control and silica "seed" particles (without Cu loading) as negative control. Bacterial growth in solution was measured against different concentrations of C-S CuSiO2NP to determine the Minimum Inhibitory Concentration (MIC) value. The estimated MIC values were 2.4 microg metallic Cu/mL for both E. coli and B. subtilis. Bac-light fluorescence microscopy based assay was used to count relative population of the live and dead bacteria cells. Antibacterial study clearly shows that C-S CuSiO2NP is more effective than insoluble Cu hydroxide particles at equivalent metallic Cu concentration, suggesting improvement of Cu bioavailability (i.e., more soluble Cu) in C-SCuSiO2NP material due to its core-shell design.

Deposition and characterization of ZnO:Mg thin films: the study of antibacterial properties

ZnO:Mg thin films with different amounts of Mg were deposited on a glass substrate using the spray pyrolysis technique. The structural, optical and antibacterial properties of the films were studied as a function of the dopant concentration. The ZnO:Mg films were characterized using methods such as x-ray diffractometry, scanning electron microscopy, scanning tunneling microscopy and UV–Vis spectroscopy. The samples display hexagonal wurtzite structure, with no secondary phase. Morphological studies indicated the deposition of a uniform film, and particle size decreases with Mg doping. Optical studies revealed that the optical band gap and optical transmittance increase with Mg concentration. The antibacterial activities of the samples against Escherichia coli (gram-negative) cultures were tested by the drop test method, which shows that Mg doping increases antibacterial activities of thin films.