Highest Antimicrobial Effect Research Articles

Https://acgpubs.org/doc/20220107214746A3-RAFC-2107-2149.pdf

In this study, antibacterial and antifungal properties of four medlar extracts obtained using four different solvents, ethanol, methanol, acetone and water, were investigated. The disk diffusion method was used to determine the antimicrobial effects of the extracts. In addition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) values were determined. The antibacterial effect of the pure water extract of medlar on S. aureus bacteria was found to be high (11.46 mm). In addition, the MIC and MBC values of the pure water extract were determined as 35.15 and 23.39 µg/mL for S. aureus bacteria. When the antifungal effect was examined, the antifungal effect of the pure water extract of medlar against P. crysogenum was found to be high (14.00 mm). The MIC and MFC values of the pure water extract of medlar are 23.43 and 11.72 µg/mL for P. crysogenum, respectively. Therefore, it was concluded that the pure water extract had the highest antimicrobial effect.

Cefixime-Containing Silica Nanoseeds Coated by a Hybrid PVA-Gold Network with a Cys–Arg Dipeptide Conjugation: Enhanced Antimicrobial and Drug Release Properties

Therapeutic nano-bioconjugates (TNBCs) as an advanced class of drug delivery systems have attracted much attention due to more efficacy than the individual medications. Hence, in this study, a novel anti-infection TNBC system is designed based on highly porous silica nanoparticles, gold nanoparticles (AuNPs), and hybridized polyvinyl alcohol (PVA) for the efficient delivery of cefixime (CFM). Furthermore, a conjugation of cysteine-arginine (CR) dipeptide is made onto the surfaces for the enhancement of cell adhesion. Concisely, the AuNPs incorporated inside the PVA network play the key role in the controlled release process triggered by localized surface plasmon resonance (LSPR) heating. The drug content of the CFM-containing cargo (named as CFM@SiO2/PVA/Au-CR) and related release profile have been precisely studied by the confirmed analytical methods. Eventually, confocal microscopy on the stained cells has revealed that the TNBC particles are capable of entering the Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacterial cells better than the individual CFM. Also, optical density experiments (OD600) have corroborated that the prepared CFM@SiO2/PVA/Au-CR TNBC includes a high antimicrobial effect on K. pneumoniae and E. coli cells with (93.0 ± 1.5) % and (86.8 ± 1.0) % success rates, respectively, whereas the same dosage of the individual CFM has shown a lower effect on the cell growth rate. Also, estimation of minimum inhibitory/bactericidal concentrations (MIC/MBC) confirmed the enhanced antibacterial property of the CFM through the presented delivery method. Overall, this product is suggested to be clinically administrated instead of the individual CFM due to its high efficacy and containing lower dosage of the antibiotic drug.

Effect of novel bottle inner surface coatings made with polylactic acid and plant extracts on the physiological status of Pseudomonas aeruginosa in real liquid foods using flow cytometry

AbstractPolylactic acid (PLA) was used, together with a novel optimized mixture (OM) of Thymus fontanesii essential oil (EOd) and the ethyl acetate (EA) fraction from Scirpus holoschoenus extract, to develop antimicrobial coatings for the inner surface of bottles for the preservation of food liquids against the pathogenic bacterium Pseudomonas aeruginosa. The effect of these coatings on the physiological status of P. aeruginosa was tested by flow cytometry (FC), filling coated bottles with previously contaminated fish soup or egg whites. As was expected, the release of phenolic compounds (PCs) from the inner coatings of the bottles to the liquid was temperature dependent. Although their antimicrobial activity in contaminated egg whites was negligible, probably due to the neutralization of bioactive substances by ovalbumin, the PLA‐OM‐coated bottles had a high antimicrobial effect when they were filled with fish soup. In this latter case, the percentage of viable cells greatly decreased, and the percentage of dead cells, killed by membrane damage, increased.

Mycochemical contents, Free-radical scavenging capacity and anti-microbial activity of wild edible mushroom from Algeria

Edible fungal species like desert truffles are often considered a healthy food source, contributing to high antioxidant and antimicrobial effects which have been used as functional foods for health promotion and disease prevention, and as treatments for a variety of diseases since antiquity. The use of desert truffles in traditional medicine has led to modern scientific investigation into their bioactive properties. This study is part of this perspective and consists of doing in a first time the determination of the nutritional value of Terfezia boudieri harvested from North-western of Algeria, Secondly, we have evalu-ated the antioxidant capacity using two complementary test systems, name-ly DPPH free radical scavenging and iron reduction (FRAP) , and finely the antimicrobial properties were screened against seventeen Gram positive and Gram negative pathogenic bacterial strains; and two strains of yeast using agar well diffusion method. The quantitative estimate of nutritional value shows that T. boudieri showed a preponderance of proteins and minerals with12.57 ± 0.13 and 15 ± 3g / 100g dry weight respectively; In addition, the methanolic extract of the ascocarps contains a high content of total phenols estimated at 44.68 ± 0.22 mg GAE / g, vitamin c and carotenoids are also present in large quantities. The methanolic extract has good capacity re-duction with iron. The free radical scavenging capacity DPPH is very inte-resting with an IC50 = 0.30 mg / ml; this last remains greater than the radical trapping capacity DPPH of ascorbic acid, whose IC50 = 0.08 mg / ml. Results of antimicrobial activity in particular against Gram (+) bacteria, the diameter of which varies from 10 ± 0.01 to 30 ± 0.57 mm where Bacillus subtilis ap-pears to be the most sensitive. On the other hand, they have moderate activ-ity against Gram (-) bacteria where Enterobacter cleacae, and Actinobacter baumannii, are the only Gram (-) bacteria that show hyper-sensitivity, our methanolic extract did not show anticandidal activity against Candida albi-cans. Therefore, the current results have demonstrated that this mushroom is nutritious and contain multiple antioxidants and has confirmed that desert truffle extracts have antimicrobial properties that are effective against com-mon pathogens that cause disease in humans, which can be further exploit-ed for clinical use.

In vitro antibacterial and antibiofilm effects of cold atmospheric microwave plasma against Pseudomonas aeruginosa causing canine skin and ear infections.

Pseudomonas aeruginosa is an opportunist pathogen that causes purulent inflammation in the skin and in the ears of dogs. Among the various virulence factors of P. aeruginosa, biofilms have been reported to result in antibiotic resistance, leading to therapeutic limitations. Cold atmospheric microwave plasma (CAMP) is known to have a high antimicrobial effect, which causes physical cell wall rupture and DNA damage. The objective of this study was to evaluate the antibacterial and antibiofilm effects of CAMP against planktonic bacteria and the biofilm of P. aeruginosa. The antibacterial effect of CAMP against P. aeruginosa ATCC10145 and clinical isolates (n = 30) was evaluated using the colony count method. We also assessed the effect of CAMP on biofilm of P. aeruginosa ATCC strain by the colony count method, water-soluble tetrazolium salt (WST) assay and confocal laser scanning microscopy (CLSM). The complete eradication of P. aeruginosa (ATCC strain and clinical isolates) was achieved within 120 s at 50 W, and clinical isolates required 60 s shorter than the ATCC strain for complete eradication at 50 W. We also confirmed the time-dependent bactericidal effect of CAMP at 50 W against ATCC strain biofilm. CAMP was effective against both planktonic bacteria and biofilm formation of P. aeruginosa. However, further studies on in vivo efficacy and safety in canine skin and ears are necessary to fully validate its clinical application.

Essential oil of Cymbopogon martini, source of geraniol, as a potential antibacterial agent against Bacillus subtilis, a pathogen of the bakery industry.

Background: Bacteria can adhere and grow on any surface due to their chemical and physical interaction, leading to the development of biofilms. Essential oils have a great potential for use in the food industry, as they can effectively prevent the presence of some pathogenic microorganisms. Species such as those in the Bacillus genus have the ability to produce toxins. Some strains of Bacillus subtilis have been related to cases of food-borne diseases. In the bakery industry, B. subtilis also has been related to "rope" disease, linked to bread preservation processes. Methods: The aim of the study was to analyse the antibacterial properties of 24 chemotyped essential oils against the growth of B. subtilis. The biological activity study was carried out using disk diffusion in agar and broth dilution methods. Results: The essential oil of Cymbopogon martinii var. motia had a high geraniol content (>80.53%) and showed a high antimicrobial effect against the Gram-positive bacterium B. subtilis. Binary combinations of Cymbopogon martinii var. motia oil with Eugenia caryophyllus showed antagonistic effects on B. subtilis. Conclusions: The essential oil of Cymbopogon martinii var. motia has an interesting potential use in the bakery industry as a preservative, in applications such as nano encapsulation for bakery doughs, active packaging of baked products, or surface disinfectants.

SYNTHESIS, SPECTRAL CHARACTERIZATION AND ANTIMICROBIAL ACTIVITIES OF BIS(CYCLOPENTADIENYL)TITANIUM(IV) COMPLEXES WITH SCHIFF BASES DERIVED FROM5-(SUBSTITUTED ARYL)-2-HYDRAZINO-1, 3, 4-OXADIAZOLE AND INDOLINE-2, 3-DIONE

Titanium(IV) complexes of type[(η5-C5H5)2TiCl(L)] have been synthesized by the reactions of bis(cyclopentadienyl)titanium(IV)dichloride with Schiff bases (LH) derived by the condensation of 5-(substituted aryl)-2-hydrazino-1,3,4-oxadiazole and indoline-2,3-dione in tetrahydrofuranin the presence oftriethylamine. All these complexes are soluble in PhNO2, DMF and DMSO.The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, UV-Vis, IR, 1H NMR, 13C NMR, XRD and SEM spectral techniques. Low molar conductance values indicate that they are non-electrolytes. The spectral data indicate5-coordinate geometry for the complexes.XRD pattern indicate that the complexes have monoclinic crystal system and particle sizes were found 49.36 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillusniger, Aspergillusflavus,ColletotrichumfalcatumandIn vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, S.typhi) and gram positive (S. aureus and B.subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The titanocene(IV) complexes have higher antimicrobial effect than the parent Schiff bases.

Multifunctional Nanofibrous Dressing with Antimicrobial and Anti-Inflammatory Properties Prepared by Needle-Free Electrospinning.

An active wound dressing should address the main goals in wound treatment, which are improved wound healing and reduced infection rates. We developed novel multifunctional nanofibrous wound dressings with three active ingredients: chloramphenicol (CAM), beta-glucan (βG) and chitosan (CHI), of which βG and CHI are active nanofiber-forming biopolymers isolated from the cell walls of Saccharomyces cerevisiae and from shrimp shells, respectively. To evaluate the effect of each active ingredient on the nanofibers’ morphological features and bioactivity, nanofibers with both βG and CHI, only βG, only CHI and only copolymers, polyethylene oxide (PEO) and hydroxypropylmethylcellulose (HPMC) were fabricated. All four nanofiber formulations were also prepared with 1% CAM. The needle-free NanospiderTM technique allowed for the successful production of defect-free nanofibers containing all three active ingredients. The CAM-containing nanofibers had a burst CAM-release and a high absorption capacity. Nanofibers with all active ingredients (βG, CHI and CAM) showed a concentration-dependent anti-inflammatory activity, while maintaining the antimicrobial activity of CAM. The promising anti-inflammatory properties, together with the high absorption capacity and antimicrobial effect, make these multifunctional nanofibers promising as dressings in local treatment of infected and exuding wounds, such as burn wounds.

Antimicrobial Activity of Calcium Hydroxide Synthesized from Indonesian Limestone against <i>Enterococcus faecalis</i>

Recurrent endodontic infections of treated teeth are mainly linked to microbial persistency in the root canal system. Enterococcus faecalis is a bacterium that is often identified in these recurrent infections. Calcium hydroxide (Ca(OH)2) is a widely used root canal medicament and is now being developed to be produced from natural materials. Ca(OH)2, which is synthesized from natural limestone from Palimanan, Indonesia, has a structure similar to Ca(OH)2, which is often used as a root canal medicament. The purpose of this study was to determine the antimicrobial property of Ca(OH)2 paste synthesized from natural limestone compared to conventional Ca(OH)2 paste. This study is an in vitro experimental study consists of 3 groups (n=24, namely, conventional Ca(OH)2 paste, limestone synthesized Ca(OH)2 paste, and saline as the negative control, for 2 intervals of time and evaluated by Total Plate Counting (TPC) method. Samples were mandibular first premolar root canal prepared by root canal preparation and contaminated with E. faecalis (ATCC 29212). The infected root canals of each group were treated by the medicaments, and samples from the root canals were taken on day 7 (n=4) and 14 (n=4). Results showed that both Ca(OH)2 groups had antimicrobial activities against E. faecalis. The limestone Ca(OH)2 paste group had the least amount of bacterial colonies on the 7th day compared to other groups. In contrast, on the 14th day, the conventional Ca(OH)2 paste had the least bacterial colonies. It can be concluded that the Ca(OH)2 paste synthesized from natural limestone has an antimicrobial effect on E. faecalis, the antimicrobial effect was higher on the 7th day but decreases on the 14th day, whereas the conventional Ca(OH)2 had a higher antimicrobial effect on day 14 compared to day 7. Further studies are expected to improve the long-term antimicrobial effectiveness and sustainability of the natural limestone synthesized Ca(OH)2 paste.

Effects of thymol and rosemary essential oils and red beet extract on low‐nitrite and carmine‐free beef Mortadella

In the present study, essential oils were used in order to reduce the nitrite in beef Mortadella, and the red beet extract was used instead of carmine. Beef Mortadella samples containing thymol and rosemary essential oils and red beet extract were produced. Chemical, physical, sensorial, and microbiological analyses were performed during the storage period. The antimicrobial and antioxidant effects of nitrite can be achieved by using thymol and rosemary essential oils. Thiobarbituric acid values of nitrite-free samples were found to be higher than nitrite-containing samples. Redness values of samples containing red beet extract and samples containing nitrite were highest. It can be recommended to use rosemary essential oil and red beet extract in reduced-nitrite and carmine-free meat products. The rosemary essential oil was reported to be more acceptable than thymol from sensorial aspect, although thymol has high antimicrobial and antioxidant effects and high phenolic content when compared with rosemary essential oil. Novelty impact statement To investigate the effects of nitrite-reduced and carmine-free beef Mortadella samples at the same time with two different essential oils and red beet extract and with different quality characteristics, To rank the general tastes with multiple decision-making techniques of sensory analysis, To compare the quality characteristics of the samples.

Interstrain Variability of Human Vaginal Lactobacillus crispatus for Metabolism of Biogenic Amines and Antimicrobial Activity against Urogenital Pathogens.

Lactobacillus crispatus is the dominant species in the vagina of many women. With the potential for strains of this species to be used as a probiotic to help prevent and treat dysbiosis, we investigated isolates from vaginal swabs with Lactobacillus-dominated and a dysbiotic microbiota. A comparative genome analysis led to the identification of metabolic pathways for synthesis and degradation of three major biogenic amines in most strains. However, targeted metabolomic analysis of the production and degradation of biogenic amines showed that certain strains have either the ability to produce or to degrade these compounds. Notably, six strains produced cadaverine, one produced putrescine, and two produced tyramine. These biogenic amines are known to raise vaginal pH, cause malodour, and make the environment more favourable to vaginal pathogens. In vitro experiments confirmed that strains isolated from women with a dysbiotic vaginal microbiota have higher antimicrobial effects against the common urogenital pathogens Escherichia coli and Enterococcus faecium. The results indicate that not all L. crispatus vaginal strains appear suitable for probiotic application and the basis for selection should not be only the overall composition of the vaginal microbiota of the host from which they came, but specific biochemical and genetic traits.

Construction of Antimicrobial Material-Loaded Porous Tricalcium Phosphate Beads for Treatment of Bone Infections.

Due to low success rates of antibiotic therapy in most osteomyelitis diseases, continuous efforts have been made to fabricate local delivery systems with high antimicrobial effects. Here, we reported a kind of ε-polylysine(PL)/Ag-loaded porous tricalcium phosphate (TCP) bead instead of antibiotics as local delivery systems for the treatment of Staphylococcus aureus-caused osteomyelitis. Such local delivery systems were prepared by the fabrication of porous TCP beads at first and then the loading of Ag and PL in turn into porous TCP beads via in situ Ag-doping and layer-by-layer methods. In vitro experiments demonstrated that the release of PL and Ag was controllable. Especially, the release dosage of Ag could be controlled to be less than 0.05 ppm 28 days later. The surface coating of PL improved the cytocompatibility and antibacterial activity of local delivery systems. In vivo experiments demonstrated that the Ag/PL-loaded porous TCP beads displayed strong antibacterial activity and good osteoconductivity, and the combination of Ag and PL was better than the use of single antibacterial materials to treat S. aureus-caused osteomyelitis. The implantation of Ag into the infected marrow had low toxicity because Ag has been integrated into the TCP grains, which could be absorbed in marrow. Therefore, the Ag/PL-loaded porous TCP beads presented potential for treating osteomyelitis, especially sequestrum-debrided osteomyelitis.

One-pot synthesis and antimicrobial of novel 6-ethoxy-6-oxido-3-oxo(thioxo) (imino)-5-substituted-2,7-dihydro-1,2,4-triazolo[3,4-e][1,2,3]diazaphospholes

A series of novel 6-ethoxy-6-oxido-3-oxo(thioxo)(imino)-5-substituted-2,7-dihydro-1,2,4-triazolo[3,4-e][1,2,3]diazaphospholes 2a-f was synthesized and characterized by IR and NMR (1H, 13C, and 31P) spectroscopic analysis. The methodology developed was one-pot three-component reaction of ethyl bromoacetate, triethyl phosphite and carbo(thio)(amino)hydrazides. The synthesized compounds were screened for their antimicrobial activities. 6-Ethoxy-6-oxido-3-oxo(thioxo)-5-phenyl-2,5,7-trihydro-1,2,4-triazolo[3,4-e][1,2,3]diazaphospholes (2c,d) exhibited significantly higher antimicrobial effects against the tested bacterial and fungal strains compared to other compounds and standard drug.

Determination of antimicrobial action of "Apicold oral spray"

Introduction: The causative agents of acute tonsillopharyngitis are viruses and bacterial flora. Treatment of acute pharyngitis is mainly local, which includes aerosols with antiseptics. Aim: Study of antimicrobial action of "Apicold oral spray" on clinical isolates of microorganisms Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans isolated from patients' oropharynx in patients. Material and methods: The effect of Apicold Oral Spray (manufactured by APIPHARMA doo) on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and Candida albicans in Ukrainian patients was studied. Antimicrobial activity was assessed after 5, 10 and 20 minutes of action of one dose of "Apicold oral spray" on microorganisms. Bactericidal and fungicidal action (inhibition of cell growth of microorganisms) is expressed as a percentage according to the control. Results and discussion: Apicold Oral Spray has a 100% antimicrobial effect after 5 minutes on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans (complete growth inhibition of all 5 clinical isolates after 20 minutes). Conclusion: "Apicold oral spray" has a high antimicrobial effect on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans, which is confirmed by 100% inhibition of the growth of all bacteria after 5 minutes

The Evaluation of Anti-Microbial-Effect to Enterococcus Faecalis by Hypochlorous Acid Water

Periapical periodontitis is a major disease, and difficult to achieve successful treatment in some cases. Therefore, root canal irrigation is one of the most important processes to successful endodontic treatment. Sodium Hypochlorite (NaOCl) solution is the most commonly used root canal irrigate. However using NaOCl solution on endodontic treatment should be considered its problems such as allergy, serious tissue damage when inadvertently injected into the maxillary sinus or oral mucosa. Therefore, another root canal irrigant that is safe and has a high antimicrobial effect is desirable. In this study, Hypochlorous Acid (HClO) water was used to evaluate the microbicidal efficacy of the Enterococcus faecalis (E. faecalis) and considered the possibility to be a future root canal irrigant candidate. Original (200ppm), 10% diluted (20ppm), 25% diluted (50ppm) and 50% diluted (100ppm) HClO water were used in this study. Each experimental solution was mixed with low concentrations (5×107 CFU/ml) or high concentration (5×109 CFU/ml) of E. faecalis at 30 seconds, 1minute, 3 minutes, 5 minutes respectively. Then they were placed onto BHI agar plates and incubated for 48 h at 37 ºC, followed by counting the number of Colony formation. The results showed that in the condition of 5×107 CFU/ml E.faecalis, no colony formation was shown within 30 seconds by 50 % diluted HClO water. Whereas only original water was attained to inhibit colony formation completely within 30 seconds under the density of 5×109 CFU/ml E, faecalis. In conclusion, 200ppm HClO water has a capacity to anti-microbiological effect against E.faecalis same as NaOCl solution. Keywords: root canal irrigant, hypochlorous acid (HClO) water, Enterococcus faecalis (E. faecalis)

Biochemical compositions, antioxidant activity, and in vitro antibacterial activity of extract from wild bitter melon (Momordica charantia var. abbreviata Ser.)

Wild bitter melon (Momordica charantia var. abbreviata Ser.) is a type of vine that grows wildly in the mountains and plains in Vietnam. The main use parts of the tree are fruit, stem, and leaf that can be eaten as vegetables. This study aims to (1) identify several bioactive chemical compounds in the stems and leaves of bitter melon trees in the forests in the district of Mang Yang, Gia Lai province; (2) evaluate the nutrient composition, antioxidant activity, and antimicrobial ability of fresh juice and extract with ethanol 70°. The results indicated that fresh juice and ethanol 70° extract currently inhibited the growth of experimental strains of microorganisms, in which ethanol 70o extract gives the highest antimicrobial effect. The qualitative results determined that the chemical components of wide bitter melon consist of flavonoids, saponins, tannins, free reducing sugar, organic acids, starch, and fatty acids as the basis for the standardization of exploitation of medicinal resources this material.

Evaluation of antibacterial properties of Chitosan Modified Glass Ionomer on StreptococcusMutans in Comparison With the Conventional glass ionomer

Purpose: To evaluate the antibacterial characters of Glass Ionomer modified with CH on Streptococcus Mutans in Comparison With the original glass ionomer. Materials and methods: caries removal of 30 extracted primary molars, these teeth divided into three groups the first group restored with chitosan modified glass ionomer and second one restored with conventional glass ionomer and the third group restored with glacial acetic acid modified glass ionomer then sterilized at oven 60c for 72 hours. Each group was placed in mitis salivarius media with well-defined number of bacteria of streptococcus mutans, then left them for 48 hours , after 48 hours solution of each group was taken and was placed in mitis salivarius plate for another 48 hours and then bacterial counting was made to see if number of bacteria increased or decreased. Results: The Chitosan modified glass ionomer had higher antimicrobial effect than conventional glass ionomer and glass ionomer modified with glacial. Statistical analysis between the groups revealed that actually a statistically considerable difference between the all groups (P-value < 0.0001). Conclusion: Chitosan can be used as a natural material for modification of glass ionomer to increase the antibacterial effect against streptcoccus mutans and also should be supported by in vivo studies.

Optimization and antimicrobial efficacy of curcumin loaded solid lipid nanoparticles against foodborne bacteria in hamburger patty.

The aim of the present study was to design a delivery system of curcumin (CU) loaded solid lipid nanoparticles (CU-CSLNs) for evaluating the antimicrobial properties in hamburger patty. Solid lipid nanoparticle (SLN) was prepared through a homogenizing technique. A response surface methodology was applied to optimize the CU-CSLNs to minimize the particle size (PS), polydispersity index (PDI), as well as to maximize the zeta potential to avoid aggregation of particles. The optimized sample revealed a spherical morphology under scanning electron microscope (SEM) and dynamic light scattering (DLS) with particle sizes of 126.87± 0.94nm and 0.21± 0.025 PDI. The zeta potential and encapsulation efficiency (EE %) were found to be -30± 0.3mV and 99.96± 0.01%, respectively. The CSLNs exhibited higher in vitro antimicrobial effect (142µg·ml-1 ) against Staphylococcus aureus and generic Escherichia coli as compared to free CU (1000µg·ml-1 ). Finally, the CSLNs antimicrobial effect was tested in hamburger patty inoculated with foodborne pathogens during eight days of storage at 4 °C. The results indicated that CSLNs had a higher antimicrobial effect than free CU. This study provides insight into the preparation of the novel antimicrobial nanoparticles for food safety applications.

Modulation of aggregation behavior, antimicrobial properties and catalytic activity of piperidinium surfactants by modifying their head group with a polar fragment

To establish the effect of surfactants structure on their functional activity a number of alkyl-N-hydroxyethylpiperidinium bromides with different length of the hydrophobic tail were synthesized and characterized. Aggregation parameters of these surfactants were determined using tensiometry and fluorimetry. It was shown that the piperidinium surfactants, including those functionalized with OH groups, show a high antimicrobial effect at concentrations lower than critical micelle concentration for both bacteria and fungi, with the low hemolytic activity revealed. In addition, these surfactants were studied as micellar catalysts in alkaline hydrolysis of carboxylic acid esters. Micellar catalytic effect increases with an growth in the length of the alkyl tail, as well as with an increase in the number of hydroxy groups in surfactant molecule and can exceed two orders of magnitude.

Antibacterial activities of hexadecanoic acid methyl ester and green-synthesized silver nanoparticles against multidrug-resistant bacteria.

Antibacterial drug resistance is considered one of the biggest threats tohuman health worldwide, and the overuse of antibiotics accelerates this problem. Multidrug-resistant (MDR) bacteria are becoming harder to treatas the antibiotics used to treat them become less effective. Therefore, it is necessary to evaluate novel methods to control MDR bacteria. In this study, 40 bacterial isolates were collected from diabetic patients. The sensitivity of 40 bacterial isolates to seven antibiotics was evaluated. Four bacterial isolates were resistant to all antibiotic groups. The MDR pathogenic bacteria were selected and identified morphologically and biochemicallyand confirmed by VITEK® 2 system as follows: Staphylococcus aureus W35, Pseudomonas aeruginosa D31, Klebsiella pneumoniae DF30, and K. pneumoniae B40. Identification of the most resistant P. aeruginosa D31 was confirmed by the sequencing of a 16S ribosomal RNA gene with an accession number (MW241596). The inhibitory activity of eight types of native grown plant extracts against MDR bacteria was studied. Clove alcoholic extract (CAE) showed the highest inhibitory activity against MDR bacteria. Gas chromatography-mass spectrometry analysis of partially purified CAE at 0.9 Rf detected by thin-layer chromatography showed an active compound named hexadecenoic acid methyl ester with the highest antimicrobial effect against clinical pathogenic bacteria. The formation of silver nanoparticles (AgNPs) by CAE was studied. Evaluation of AgNPs was investigated by X-ray diffraction, UV-Vis, and transmission electron microscopy. The antibacterial effect of AgNPs after 2, 4, and 6 days in light and dark conditions was evaluated. Finally, the AgNPs synthesized using CAE possessgood inhibition activity against the tested pathogenic bacteria. As a result, the bactericidal components listed above were promising in reducing MDR bacteria and can be used for treatments of bacterial infection and in the development of safe products with a natural base.