Highest Antimicrobial Effect Research Articles

Study of Synthesis, Characterization, DFT, and In Vitro Biological Activity of Cu(II), Co(II), and Fe(II) Metal Complexes Based on Heterocyclic Azo Pyrazole Dye Ligand

A new azo dye ligand was synthesized by coupling 5-amino-3-methyl-1-phenylpyrazole with a diazonium ion of 2-amino-1-naphthalene sulfonic acid. Its Co(II), Fe(II), and Cu(II) complexes were also synthesized. This ligand and its complexes were characterized based on elemental analysis, IR, 1H NMR, UV-vis spectra, and thermogravimetric analysis. The data showed that the proposed complexes have an octahedral geometry around the central metal ion. The nonelectrolytic nature of the complexes was confirmed by molar conductance measurement. X-ray powder diffraction indicates that Co(II) and Fe(II) complexes are amorphous in nature, whereas the Cu(II) complex has crystalline and amorphous phases. The bond strength and molecular stability between the interaction of metal ions and the ligand were investigated by density functional theory (DFT). The in vitro antibacterial activity of the ligand and complexes was tested against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Neisseria gonorrhoeae) and a fungus (Candida albicans). The Cu(II) complex exhibited a high antimicrobial effect against all tested microorganisms. The DNA fragmentation percentage and cytotoxic activity against human liver cancer cells (HepG2) were evaluated. All tested compounds showed potential anticancer activity, and the Co(II) complex showed better activity results than the other tested compounds, with IC50 = 19.55 μg/mL.

New thiadiazole modified chitosan derivative to control the growth of human pathogenic microbes and cancer cell lines

The emergence of multidrug-resistant microbes and the propagation of cancer cells are global health issues. The unique properties of chitosan and its derivatives make it an important candidate for therapeutic applications. Herein, a new thiadiazole derivative, 4-((5-(butylthio)-1,3,4-thiadiazol-2-yl) amino)-4-oxo butanoic acid (BuTD-COOH) was synthesized and used to modify the chitosan through amide linkages, forming a new thiadiazole chitosan derivative (BuTD-CH). The formation of thiadiazole and the chitosan derivative was confirmed by FT-IR, 1H/13C-NMR, GC–MS, TGA, Elemental analysis, and XPS. The BuTD-CH showed a high antimicrobial effect against human pathogens Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Candida albicans with low MIC values of 25–50 μg ml−1 compared to unmodified chitosan. The in-vitro cytotoxicity of BuTD-CH was evaluated against two cancer cell lines (MCF-7 and HepG2) and one normal cell (HFB4) using the MTT method. The newly synthesized derivatives showed high efficacy against cancerous cells and targeted them at low concentrations (IC50 was 178.9 ± 9.1 and 147.8 ± 10.5 μg ml−1 for MCF-7 and HepG2, respectively) compared with normal HFB4 cells (IC50 was 335.7 ± 11.4 μg ml−1). Thus, low concentrations of newly synthesized BuTD-CH could be safely used as an antimicrobial and pharmacological agent for inhibiting the growth of human pathogenic microbes and hepatocellular and adenocarcinoma therapy.

Biocompatibility and biocidal effects of modified polylactide composites.

Polylactide (PLA) materials treated with antimicrobial fillers represent a suitable alternative to the production of medical devices. Their advantage is that they can prevent the growth of microorganisms and the formation of microbial biofilms on the surface and around composites. The work is focused on the evaluation of biocompatibility and biocide effect of PLA composite films filled with vermiculite and graphene oxide modified with silver (Ag+ and Ag nanoparticles), hexadecylpyridinium (HDP) and hexadecyltrimethylammonium (HDTMA) cations and their degradation leachates monitored at 1-3-6-month intervals. The antimicrobial effect of the leachates was detected by microdilution methods on gram-negative (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis), gram-positive (Staphylococcus aureus, Streptococcus salivarius) bacteria and yeast (Candida albicans). The biocidal effect of composites on biofilm formation on the surface of composites was monitored by Christensen method and autoaggregation and motility tests. The biocompatibility of the composite and the leachates was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) cytotoxicity assay. The evaluation of the antimicrobial effect of the leachates demonstrated that leachates of PLA composite filled with graphene oxide and Ag+ showed a stronger antimicrobial effect than leachates of PLA composite filled with vermiculite and Ag+ and Ag nanoparticles. The leachates of PLA composites containing vermiculite with HDP and HDTMA cations had a higher antimicrobial effect on G+ bacteria and yeast than G- bacteria. Bacterial growth, biofilm formation, autoaggregation and motility of the tested bacteria were most inhibited by the composite with vermiculite and Ag+ and Ag nanoparticles. Even after a 6-month degradation of this composite, bacterial growth and biofilm formation continued to be strongly inhibited up to 42 and 91%, respectively. The cytotoxic effect was proved only in the leachate of the composite with vermiculite containing HDP after 6 months of its degradation. Tests evaluating the biocompatibility of materials have shown that the vermiculite is the most preferred carrier and can be used in the future to bind other compounds. The study confirmed that PLA composite filled with vermiculite and Ag+ and Ag nanoparticles was the most stable and effective composite with the best biocompatible and biocidal properties.

Efficacy of plasma activated saline in a co-culture infection control model

Plasma activated liquids have demonstrated antimicrobial effects and receive increasing attention due to the potential to strengthen the armoury of novel approaches against antibiotic resistant bacteria. However, the antibacterial activity and cytotoxic effects of these solutions need to be understood and balanced before exposure to humans. In this study, the antibacterial effects of plasma activated saline (PAS) were tested against Gram negative and positive bacteria, and HaCaT keratinocytes were used for cytotoxicity studies. For the first time, a co-culture model between these bacteria and eukaryotic cells under the influence of PAS has been described. Exposure of saline to plasma resulted in high concentrations of nitrate, hydrogen peroxide and a reduction of pH. PAS caused high antibacterial effects in the co-culture model, accompanied by high cytotoxic effects to the monolayer of mammalian cells. We present evidence and provide a deeper understanding for the hypothesis that upon treatment with PAS, chemical species generated in the liquid mediate high antimicrobial effects in the co-culture setup as well as mitochondrial depolarization and glutathione depletion in HaCaT cells and cell lysis due to acidic pH. In conclusion, PAS retains strong antibacterial effects in a co-culture model, which may have unintended negative biological effects on mammalian cells.

Synthesis, antimicrobial and antifungal activity of 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles

To select a molecule that could become a promising pharmacological agent, chemists use already-known heterocyclic bases by adding pharmacologically active groups. One such heterocyclic system is 1,2,4-triazole base, on the basis of which a huge number of biologically active compounds have already been found. It is known that 1,2,4-triazole derivatives show a fairly high antimicrobial and antifungal effect while remaining low-toxic compounds and 5-alkylthio-1,2,4-triazoles exhibit antimicrobial and antifungal activity. Based on the literature search, it can be concluded that 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles are insufficiently studied. The aim of the work was to synthesize and investigate antimicrobial and antifungal activity among 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles. Materials and methods. It was used 5-(2-bromophenyl)-4-phenyl-4H-1,2,4-triazole-3-thiol as a starting substance, which was synthesized by previously described techniques. 3-(2-Bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles were obtained by alkylation of the starting thiol with halohenalkanes (according to the first method) and the addition of hydrochloric acid in an alcoholic medium, then subsequent heating in microwave synthesis system (by the second method). To study the antimicrobial and antifungal activity of the newly synthesized 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles, the method of serial dilutions was used according to guidelines. Results. 3-(2-Bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles were obtained by two methods: a) an equivalent amount of halohenalkane was added to 5-(2-bromophenyl)-4-phenyl-4H-1,2,4-triazole-3-thiol (I) (solvent – KOH pre-dissolved in 2-propanol). Boiled to pH = 7; b) 5-(2-bromophenyl)-4-phenyl-4H-1,2,4-triazole-3-thiol (I) (solvent – methyl or 1-propyl alcohol and 10 drops of HCl) was heated in Milestone Flexi Wave microwave synthesis system. Reaction conditions: The mixture was heated for 45 minutes at a temperature of 150 °C, a pressure 14.4 bar, ΔMW ≈ 200 W. The completeness of the reaction was determined using a gas chromatograph Agilent 7890B with a mass spectrometric detector 5977B. Antimicrobial and antifungal activity of 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles (6 new compounds) was investigated. The most active compound with antifungal and antimicrobial effect was IIi. Substances IIa–IIe had moderate antimicrobial effect. Conclusions. New 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazoles were synthesized by two methods. The antimicrobial and antifungal activity was investigated for the obtained compounds. The most active compound was 3-(2-bromophenyl)-5-(decylthio)-4-phenyl-4H-1,2,4-triazole (IIi). Some conclusions were drawn regarding the dependence of “structure – antimicrobial and antifungal effect”: the antimicrobial effect increased with the length of the carbon radical; changing the decyl radical to another one in the molecule 3-(2-bromophenyl)-5-(alkylthio)-4-phenyl-4H-1,2,4-triazole reduced antifungal activity.

The in vitro Effect of Heat, Lactic Acid-Silver Nanoparticle Combination on Shiga Toxigenic Escherichia coli

Lactic acid and silver nanoparticle compositions’ effects as antimicrobial to reduce Shiga Toxigenic Escherichia coli (STEC) contamination were studied in vitro conditions. Four silver nanoparticle sizes, 20, 40, 100, 150 nm with lactic acid (LA) solutions of 1.5%, 2%, 2.5%, were applied and heated in a water bath to 20°C, 40°C and 50°C. Shiga toxigenic E. coli O26, O103, O111, O145 and O157 were used as control microorganism. Microbial counts were analyzed using a general linear model univariate test. According to our results, 20, 100, and 150 nm Ag Nanoparticles (AgNPs) in 2% and 2.5% LA density at 40 °C and 50 °C have a decrease of 3 log10 CFU/ml and more. The highest antimicrobial effect was seen at 150 nm AgNP, 2.5% LA at 50°C. Our findings show that AgNP combined with lactic acid can be a low-cost reduction method and promise a novel antimicrobial agent.

Development and characterization of alginate-derived crosslinked hydrogel membranes incorporated with ConA and gentamicin for wound dressing applications.

This work sought to develop and characterize alginate-based hydrogel membranes containing ConA and gentamicin for wound dressing applications. A rotational central composite design was applied to evaluate the influence of three variables (alginate, glycerol, calcium chloride) on the macroscopic quality of alginate-derived membranes. The samples with best quality were selected for incorporation of ConA and gentamicin and evaluation of antimicrobial action against Staphylococcus aureus and Pseudomonas aeruginosa. Following, the morphological, mechanical and physicochemical characteristics (thickness, humidity, roughness, color, water vapor sorption, cytocompatibility) of the membrane with higher antimicrobial effects were characterized. Among the seventeen alginate-based membranes, the samples 3, 4, 7 and 12 were selected based on their quality score. The sample 3 exhibited the highest antimicrobial activity. The incorporation of ConA did not change the microbial inhibition by gentamicin; however, ConA/gentamicin-loaded membranes showed better distribution of both compounds, in addition to greater roughness and transparency. The ConA/gentamicin-loaded membranes were also more efficient for absorption of liquids and vapors without showing cytotoxicity. The results obtained by ConA/gentamicin-loaded membranes reveals promising perspectives in the treatment of skin lesions, demonstrating effective antimicrobial activity and encouraging the subsequent in vivo investigation of healing properties.

Essential Oil Variability in Iranian Populations of Heracleum persicum Desf. ex Fischer: A Rich Source of Hexyl Butyrate and Octyl Acetate.

Heracleum persicum Desf. ex Fischer seeds are a rich source of essential oils (EOs) with high antimicrobial and antioxidant effects. In order to determine the phytochemical variability in various Iranian H. persicum populations, seed samples were collected from 10 different climatic locations. The current study indicated that hexyl butyrate (20.9–44.7%), octyl acetate (11.2–20.3%), hexyl-2-methylbutyrate (4.81–8.64%), and octyl 2-methyl butyrate (3.41–8.91%) were the major components of the EOs. The maximum (44.7%) and the minimum (20.9%) content of hexyl butyrate were obtained from Kaleibar and Sari populations, respectively. Moreover, the octyl acetate content ranged from 2% (in Mahdasht) to 20.3% in Torghabeh population. The CA and PCA analysis divided the 10 Iranian H. persicum populations into three major groups. Populations from Khanghah, Kaleibar, Shebeilo, Showt, Mahdasht, and Amin Abbad showed a distinct separation in comparison with the other populations, having high contents of hexyl butyrate (39.8%) and low contents of octyl acetate (13.5%) (Chemotype II). According to correlation analysis, the highest correlation coefficient was among habitat elevation and hexyl butyrate content. In addition, the mean annual precipitation was negatively correlated with the content of hexyl butyrate. Although octyl acetate content showed high correlation with soil EC and mean annual temperature, it was not statistically significant. In general, in order to have plants with a high content of hexyl butyrate, it is recommended to harvest these plants from regions with high altitude and low rainfall such as Kaleibar.

Sodium alginate edible coating containing Ferulago angulata (Schlecht.) Boiss essential oil, nisin, and NaCl: Its impact on microbial, chemical, and sensorial properties of refrigerated chicken breast

This study aimed to investigate the effects of sodium alginate (ALG) coating incorporated with Ferulago angulata (Schlecht.) Boiss essential oil (FAEO, 10 and 20 mg/mL), nisin (N, 500 and 1000 IU/mL), and NaCl (2 %) on microbial (lactic acid bacteria, LAB; total viable bacteria, TVC; psychrotrophic bacteria; Pseudomonas; Enterobacteriaceae, and yeast and mold), chemical (pH, PV, TVB-N, and TBARS), sensory (color, odor, texture, and overall acceptance), and antioxidant properties of refrigerated (4 °C) chicken breasts. GC–MS analysis revealed that trans-β-ocimene (45.36 %) and α-pinene (18.01 %) constituted most of the components in FAEO. The antioxidant properties of FAEO were evaluated via the DPPH method. The IC50 value of FAEO was 562 mg/mL. The results of antimicrobial evaluations indicated that there was no significant difference between control and ALG treatments (p > 0.05). The highest antimicrobial effect was associated with ALG + FAEO2 + N2 + NaCl treatment. The logarithmic reduction of the TVC, psychrotrophic count, Pseudomonas count, Enterobacteriaceae, LAB, as well as yeast and mold count in the ALG + FAEO2 + N2 + NaCl treatment were 1.40, 0.92, 1.20, 1.02, 0.88, and 1 log CFU/g, respectively compared to the control treatment. The initial level of TVB-N in the control treatment was 8.26 mg/100 g, which reached 42.84 mg/100 g at the end of the storage period. In ALG+ FAEO2 + N2 + NaCl treatment, the lowest TVB-N was observed, being 36.37 mg/100 g at the end of the storage period. The initial level of PV in the control treatment was 0.14 meq/kg, which reached 3.04 meq/kg at the end of the storage period. In the treatments containing FAEO, PV was lower than in other treatments, indicating the antioxidant properties of FAEO. There was a significant difference between control and other treatments in pH and TBARS evaluation (p < 0.05). The samples treated with FAEO had a lower pH than control. At the end of the storage period, the TBARS level in the control treatment reached 1.20 mg MDA/kg, while in the treatment of ALG+ FAEO2 + N2 + NaCl treatment, its level was 0.36 mg MDA/kg. The results of sensory properties indicated that in evaluating the color, odor, texture, and overall acceptance on the final days, treatments containing FAEO, nisin, and NaCl had higher scores due to their antimicrobial and antioxidant properties. In conclusion, this study indicated that adding FAEO, nisin, and NaCl to ALG coating would enhance the shelf-life of chicken meat.

Physicochemical characteristics, GABA content, antimicrobial and antioxidant capacities of yogurt from Murrah buffalo milk with different fat contents

This study aimed to prepare yogurt from Murrah buffalo milk with high GABA content and low fat content while keeping the physicochemical characteristics, antimicrobial effects, and antioxidant capacity within acceptable levels. Yogurt samples were prepared using buffalo milk by adjusting the fat content to 0.2%, 3.5%, and 6.5%. The results showed that the fat content had no significant effects on the pH, titratable acidity, water activity, and cell viability. However, the fat content significantly affected the viscosity, particle size, and texture profile analysis of the yogurt. The GABA content was significantly higher in the 0.2% fat yogurt (61.57 ± 3.22 mmol L−1) compared to the 3.5% fat yogurt (43.64 ± 1.99 mmol L-1) and 6.5% fat yogurt (27.84 ± 2.64 mmol L−1). Glutamic acid and proline were the most abundant amino acids in the yogurt. In contrast, saturated fatty acids (butyric, lauric, myristic, palmitic, stearic, and oleic) and linoleic acid were abundant. Yogurt with 3.5% fat showed significantly high antioxidant capacity and antimicrobial effects on E. coli O157 and Salmonella sp. Based on the results, fat content significantly affects the rheological properties, GABA content, and antioxidant and antimicrobial capacities of yogurt. In the future, 3.5% fat should be chosen as the optimized formula for large-scale yogurt production from Murrah buffalo milk.

Perspectives for Uses of Propolis in Therapy against Infectious Diseases.

Propolis has gained wide popularity over the last decades in several parts of the world. In parallel, the literature about propolis composition and biological properties increased markedly. A great number of papers have demonstrated that propolis from different parts of the world is composed mainly of phenolic substances, frequently flavonoids, derived from plant resins. Propolis has a relevant role in increasing the social immunity of bee hives. Experimental evidence indicates that propolis and its components have activity against bacteria, fungi, and viruses. Mechanisms of action on bacteria, fungi, and viruses are known for several propolis components. Experiments have shown that propolis may act synergistically with antibiotics, antifungals, and antivirus drugs, permitting the administration of lower doses of drugs and higher antimicrobial effects. The current trend of growing resistance of microbial pathogens to the available drugs has encouraged the introduction of propolis in therapy against infectious diseases. Because propolis composition is widely variable, standardized propolis extracts have been produced. Successful clinical trials have included propolis extracts as medicine in dentistry and as an adjuvant in the treatment of patients against COVID-19. Present world health conditions encourage initiatives toward the spread of the niche of propolis, not only as traditional and alternative medicine but also as a relevant protagonist in anti-infectious therapy. Production of propolis and other apiary products is environmentally friendly and may contribute to alleviating the current crisis of the decline of bee populations. Propolis production has had social-economic relevance in Brazil, providing benefits to underprivileged people.

The Evaluation of Possibility for Future Root Canal Irrigant Candidate by Catechin Solution

To treatment for periapical periodontitis, root canal irrigation is one of most important process to obtain success of healing Sodium hypochlorite (NaOCl) is the most widely used as root canal irrigant. However using NaOCl on endodntics 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 safety and having high antimicrobial effect is desirable. In this study, catechin was to evaluated microbicidal efficacy to the Enterococcus. faecali (E.faecalis) and considered the possibility to be the future root canal irrigant candidate. 10%(100mg/ml) to 30%(300mg/ml) of catechin solution were prepared and used for this study. The anti-microbiologic effect against E.faecalis was evaluated with different concentrations (low: 5x107 CFU/ml, high: 5x109 CFU/ml), and different reaction time like as from 5minutes to 30 minutes respectively. Then they were placed onto BHI agar plates and incubated for 1 week at 37ºC. Then the number of colony formation was counted. Prevent colony formation by 30% catechin solution was caused within 5minutes in low density of E.faecalis, and within 20 minutes in high density of it. 20% catechin solution leaded to no colony formation at 10 min (low density) and 30 min (high density), respectively. For 10% catechin solution, it was necessary to attain no colony formation should be 30 minutes (low density), however high density of E.faecalis was not killed completely within 30minutes. These results suggested that Catechin has a benefit to anti-microbiologicl effect against E.faecalis. However to determine Satisfactory anti-microbiological effect, high concentration of catechin solution and long reaction time should necessary. Therefore usage of catechin in future root canal treatment might be recommended not for candidate of root canal irrigant but for candidate of intracanal medication.

Formulation and Evaluation of Moxifloxacin Loaded Bilosomes In-Situ Gel: Optimization to Antibacterial Evaluation.

In this study, moxifloxacin (MX)-loaded bilosome (BS) in situ gel was prepared to improve ocular residence time. MX-BSs were prepared using the thin-film hydration method. They were optimized using a Box–Behnken design (BBD) with bile salt (A, sodium deoxycholate), an edge activator (B, Cremophor EL), and a surfactant (C, Span 60) as process variables. Their effects were assessed based on hydrodynamic diameter (Y1), entrapment efficacy (Y2), and polydispersity index (Y3). The optimized formulation (MX-BSop) depicted a low hydrodynamic diameter (192 ± 4 nm) and high entrapment efficiency (76 ± 1%). Further, MX-BSop was successfully transformed into an in situ gel using chitosan and sodium alginate as carriers. The optimized MX-BSop in situ gel (MX-BSop-Ig4) was further evaluated for gelling capacity, clarity, pH, viscosity, in vitro release, bio-adhesiveness, ex vivo permeation, toxicity, and antimicrobial properties. MX-BSop-Ig4 exhibited an optimum viscosity of 65.4 ± 5.3 cps in sol and 287.5 ± 10.5 cps in gel states. The sustained release profile (82 ± 4% in 24 h) was achieved with a Korsmeyer–Peppas kinetic release model (R2 = 0.9466). Significant bio-adhesion (967.9 dyne/cm2) was achieved in tear film. It also exhibited 1.2-fold and 2.8-fold higher permeation than MX-Ig and a pure MX solution, respectively. It did not show any toxicity to the tested tissue, confirmed by corneal hydration (77.3%), cornea histopathology (no internal changes), and a HET-CAM test (zero score). MX-BSop-Ig4 exhibited a significantly (p < 0.05) higher antimicrobial effect than pure MX against Staphylococcus aureus and Escherichia coli. The findings suggest that bilosome in situ gel is a good alternative to increase corneal residence time, as well as to improve therapeutic activity.

A review, tabulation of the Antimicrobial Effect of Silver Nanoparticles

Silver nanoparticles are used in every single aspect of science including medical and pharmaceuticals, as they have high antimicrobial effects because of their large surface area to volume ratio, which is the curiosity of new researchers on antibiotics, the growing microbial resistance and the development of resistant strains. Silver nanoparticles are the superabundant antimicrobial agent for bacteria, fungi, algae and are less noxious to human cells than bacterial cells. Silver nanoparticles are used to control germination in a variety of applications, such as antibacterial coating for medicinal materials to promote wound healing and prevent infection, and antibacterial vaccines to control bacterial diseases. In the current work, a review of the antimicrobial properties of silver nanoparticles is compiled in tabular form reported by different research groups. The aim of this review is to discuss the present state of affairs and suggestions for future possibilities in this field.

Antimicrobial Effect of Honeys Collected in Bingol Region

In this research, the antimicrobial effects of honeys collected from Genç, Kiğı, Sancak, and Yedisu districts of Bingöl province were investigated by disc diffusion method. The antimicrobial effects of honey samples prepared at three different concentrations (500, 250, and 125 mg mL-1) were tested using Staphylococcus aureus ATCC 29213 and Listeria monocytogenes NCTC 5348 bacteria as Gram positive (+), Escherichia coli ATCC 25922 bacterium as Gram negative (-), Saccharomyces cerevisiae ATCC 76521 as yeast, and Candida albicans ATCC 90028 as fungus (mold). In addition, Ampicillin/Sulbactam (SAM) (20 µg/disc) was used as an antibiotic to better evaluate the antimicrobial effects of honeys in this research. The antimicrobial effect of Ampicillin/Sulbactam (SAM) (20 µg disc-1) against the microorganisms used in honey samples was also tested with the same method.As a result; while the 500 and 250 mg mL-1 concentrations among honey samples prepared at three different concentrations (500, 250, and 125 mg mL-1) have an antibacterial effect against Staphylococcus aureus, the antibacterial effect of the concentrations of 125 mg mL-1 against Staphylococcus aureus was not detected. All honey samples at three different concentrations showed no antibacterial effect against Listeria monocytogenes. While only the 500 mg mL-1 concentrations from different concentrations of Genç and Yedisu honey samples were found to have an antibacterial effect against Escherichia coli, the antibacterial effects of Kiğı and Sancak honey samples prepared at different concentrations against Escherichia coli were not detected. It was determined that only 500 mg mL-1 concentrations from all honey samples had an antimicrobial effect against Saccharomyces cerevisiae, while the other 250 and 125 mg mL-1concentrations did not have an antimicrobial effect against Saccharomyces cerevisiae. The studied concentrations of all honey samples did not show an antifungal effect against Candida albicans. Moreover, Ampicillin/Sulbactam (SAM) (20 µg disc-1) was found to have a high antimicrobial effect against Staphylococcus aureus and Listeria monocytogenes (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria), Saccharomyces cerevisiae (yeast), and Candida albicans (fungus) microorganisms.

Potential application for antimicrobial and antileukemic therapy of a flavonoid-rich fraction of Camellia sinensis

The antimicrobial and antileukemic effect of a purified fraction of flavonoids from the leaves of Camellia sinensis was evaluated. An extraction yield of 9.77 mg.g-1 total flavonoids was recovered through a pressurized liquid extraction associated with solid-phase extraction. This fraction was tested against pathogenic microorganisms (Staphylococcus, Salmonella, and Enterococcus), considering the minimum inhibitory concentration. In addition, the human monocyte cell line THP-1, derived from a patient with acute monocytic leukemia, was used for the antitumor assay. The results show that the flavonoid-rich fraction obtained by coupling a Pressurized Liquids Extraction in-line with a Solid Phase Extraction (PLE-SPE) has a high antimicrobial effect and resulted in cell cycle blockage G0 / G1, increased DNA fragmentation, and altered leukemic cell morphology. These results suggest that a flavonoid-rich fraction obtained from Camellia sinensis can be applied as potential adjuvants in chemotherapy treatment to mitigate the side effects caused by chemotherapy or even as a supplement to cancer therapy.

The use of bacteriophage-based edible coatings for the biocontrol of Salmonella in strawberries

The physicochemical quality and the effectiveness of antimicrobial activity against Salmonella and phage stability of dip-coated strawberries were investigated in this study by using bacteriophage cocktail with four different biopolymers for a period of 5 day at +4°Ϲ. The biopolymers used in this study were whey protein concentrate (WPC), carboxymethyl cellulose (CMC), chitosan (CH), and sodium alginate (SA). The phage cocktail was prepared using S. Enteritidis and S. Typhimurium obtained from the phages isolated from different environmental sources as host bacteria. Uncoated fruit was used as a control. The color, pH, and titratable acidity (TA) of strawberry samples and the stability and antimicrobial activity of bacteriophages during storage were also investigated. Amongst all the biopolymers, WPC coating showed the least escalation in pH and the least decrease in TA. During storage, 0.7 log-unit (PFU/g) reduction in WPC coating with the bacteriophage cocktail was observed. The highest antimicrobial effect was observed in WPC with a reduction of 3.1 log (CFU/g) after 5 days when the multiplicity of infection was 1000. In the light of the results, it was concluded that the phage loaded WPC coating had much better physicochemical and microbiological quality during refrigerated storage; therefore, it could be used effectively to extend the postharvest life of strawberries.

Selective laser welding in liquid: A strategy for preparation of high-antibacterial activity nanozyme against Staphylococcus aureus

Nanozyme was considered as one of the most promising substitutes for antibiotics, due to the selective catalysis for pathogens. In this work, a high-antibacterial activity SOD-like nanozyme based on hybrid Ag/CeO2 nanocomposite was facilely prepared by using an innovative approach of selective laser welding in liquid. This prepared nanozyme displayed a high antimicrobial effect against Staphylococcus aureus under visible light illumination, the sterilization rate as high as 82.4%, which was 2.93 and 2.99 times higher than those of pure Ag and pure CeO2, respectively. The enhanced antibacterial activity was attributed to the anchoring of Ag nanospheres on the surface of CeO2 nanosheets, which induced the reduction of CeO2 bandgap and boosted the visible light harvesting. Therefore, the charge carriers can be effectively stimulated to produce abundant reactive oxygen species on the Ag/CeO2 nanocomposite via a SOD-like route. This work demonstrated a facile strategy for the preparation of high-antibacterial activity nanozyme, giving it great potential for scalable application in the biomedical and pharmaceutical industry.

Antimicrobial effect of radiant catalytic ionization.

The main purpose of micro-organisms elimination from the air and surfaces is to ensure microbiological safety in health care facilities or food production plants. Currently, many disinfection methods are used, both physical, chemical and, increasingly, biological. Scientists seek new solutions with high antimicrobial effectiveness (especially against the drug-resistant strains of bacteria), low production and operating costs, and, above all, the safety of patients and food consumers. The limitation of the methods used so far is primarily the micro-organisms acquire the resistance, mainly to antimicrobial agents. One of the new and alternative methods of disinfection is radiant catalytic ionization (RCI). RCI is an active method of air and surface purification. The technology proved high efficiency against viruses, Gram-positive and -negative bacteria, and fungi, both in the air and on surfaces (planktonic forms and biofilm). RCI has many advantages as well as some minor limitations. This overview summarizes the current knowledge about RCI technology.

In-vitro Susceptibility Profile of Pseudomonas aeruginosa to Selected Medicinal Plants Obtained from University of Calabar Farm, Nigeria

Antibiotic resistance represents the greatest challenges to global health. Strategies to curb the menace of antibiotic resistance include researching for new antimicrobials from plants. This study is aimed at determine the in-vitro susceptibility of Pseudomonas aeruginosa to Chromolaena odorata, Jatropha tanjorensis, Ocimum gratissimum, Vernonia amydalina, Hibiscus sabdariffa and Aloe barbadensis obtained within University of Calabar farm. All the test carried out were performed according to standard microbiological procedure. Ethanol was used for extraction of Phytochemicals and were purified using column chromatography. In-vitro susceptibility of selected plants against P. aeruginosa was in the order C. odorata&gt;J. tanjorensis &gt; O. gratissimum &gt; H. sabdariffa &gt;V. amydalina &gt; A. barbadensis (Aloe vera). The result revealed that the leaves of C. odorata had the highest antimicrobial effect against P. aeruginosa. The first column of all the plant extracts showed no antimicrobial activity. MIC of C. odorata, J. tanjorensis, O. gratissimum and H. sabdariffa were observed in 10-7, 10-6, 10-5 and 10-4 dilution respectively. Statistical analysis between the zone of inhibitions and layers of column chromatography was significant (&lt;0.05). Ethanol extract and the third column of Chromolaena odorata, Jatropha tanjorensis, Ocimum gratissimum have great potential antibacterial activity against P. aeruginosa.