Minimum Bactericidal Concentration Research Articles

Comparative evaluation of antimicrobial efficacy of chitosan nanoparticles and calcium hydroxide against endodontic biofilm of Enterococcus faecalis: An in vitro study

Aim: The aim of the study was to assess and evaluate the antimicrobial effectiveness of chitosan nanoparticles (CSNPs) with calcium hydroxide in the elimination of Enterococcus faecalis. Materials and Methods: Using the broth microdilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of calcium hydroxide and CSNPs were measured. The antibiofilm effect of calcium hydroxide and CSNPs against E. faecalis biofilm was qualitatively analyzed using a crystal violet assay. A 7-day-old biofilms of E. faecalis grown on dentine discs were assigned to the following three groups (n = 11 dentine discs), normal saline (group I), calcium hydroxide (group II), and CSNPs (group III). Quantification of live and dead cells using confocal microscopy was done to evaluate the antibiofilm efficacy of the medicaments included in the study. Results: MIC of calcium hydroxide and CSNPs against E. faecalis was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. MBC of calcium hydroxide and CSNPs was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. Using Crystal Violet (CV) assay, calcium hydroxide and CSNPs showed biofilm inhibition at concentrations of 2.5 mg/mL and 0.625 mg/mL, respectively. Confocal laser scanning microscopy analysis found that both calcium hydroxide and CSNPs showed a significant decrease in viable cells at their MBC values compared to the control group’s normal saline. CSNPs showed a significantly lower percentage of live cells than calcium hydroxide (P < 0.05). Conclusion: The study results reveal that the antimicrobial efficacy of CSNPs is better than calcium hydroxide and normal saline against E. faecalis biofilm.

Therapeutic Potential of Mangosteen Pericarp Extract-Loaded Liposomes against Superficial Skin Infection Caused by Staphylococcus pseudintermedius in a Murine Model.

α-mangostin (α-MG) demonstrates antibacterial activity against Staphylococcus species. Therefore, this study aimed to explore the antibacterial activity of α-MG-rich mangosteen pericarp extract (MPE)-loaded liposomes against Staphylococcus isolates from companion animal skin diseases in vitro and evaluated their therapeutic potential in a murine model of superficial skin infection caused by S. pseudintermedius. α-MG-rich extract was purified from mangosteen pericarp and then complexed with γ-cyclodextrin (γ-CD), forming the inclusion complexes. Nanoliposomes containing MPE and γ-CD complexes were prepared by adding lecithin and casein. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of MPE-loaded liposomes were determined using agar dilution and broth microdilution methods. The therapeutic potential of MPE-loaded liposomes was evaluated in vivo on tape-stripped skin lesions infected with S. pseudintermedius. Purified MPE and MPE-loaded liposomes contained 402.43 mg/g and 18.18 mg/g α-MG, respectively. MPE-loaded liposomes showed antibacterial activity against clinical Staphylococcus isolates in vitro but did not show antibacterial activity against Gram-negative bacterial isolates. MPE-loaded liposomes demonstrated consistent MICs and MBCs against Staphylococcus isolates. These liposomes significantly reduced bacterial numbers and lesional sizes in a superficial skin infection model. Moreover, they reconstructed the epidermal barrier in skin lesions. The therapeutic concentrations of MPE-loaded liposomes did not induce cytotoxicity in canine progenitor epidermal keratinocyte cells. In conclusion, MPE-loaded liposomes hold promise for the development of a prospective topical formulation to treat superficial pyoderma in companion animals.

Enriched advanced platelet-rich fibrin plus gold nanoparticles against Enterococcus faecalis for its potential use in revascularization for necrotic immature permanent teeth

Background: Regenerative endodontic procedures allow reinforcement of root canal wall and continuation of root development, opening new therapeutic possibilities. The root canal system of infected teeth is colonized by a variety of microorganisms, which hinder the regenerative process, leading to treatment failure if not adequately addressed, thereby requiring careful attention to microbial control. Aim and Objective: The aim of the study was to assess the antimicrobial activity of advanced platelet-rich fibrin (A-PRF) and gold nanoparticles (AuNps) against Enterococcus faecalis. Materials and Methods: Intravenous blood (5–6 ml) was drawn from four healthy individuals, and A-PRF was prepared through centrifugation at 1500 revolutions per minute (rpm) for 14 min. A-PRF was doped with 3 µl of AuNps and centrifuged at 1000 rpm for 1 min. Antimicrobial activity was assessed using disk diffusion; inhibition zones were measured. For minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), A-PRF + AuNps were added to the microbial broth at varying concentrations to determine growth inhibition and microbial death. Results: Disk diffusion assays revealed significant antibacterial effects against E. faecalis. Norfloxacin displayed the highest mean zone of inhibition (20.33 ± 1.53 mm), followed by the Test group (A-PRF + AuNPs) (19.33 ± 0.58 mm). Multiple comparisons indicated significant differences (P < 0.001). MIC of A-PRF + AuNPs against E. faecalis was 0.031 mg/ml, with MBC at 0.015 mg/ml. Conclusion: The addition of AuNPs to A-PRF offers the potential for sustained growth factor release while maintaining the sterility of the canal, leading to successful revitalization and regeneration. The combined use of A-PRF + AuNps shows promise for enhancing revascularization in necrotic immature permanent teeth.

Comparative evaluation of antimicrobial efficacy of chitosan nanoparticles and calcium hydroxide against endodontic biofilm of Enterococcus faecalis: An in vitro study

Aim: The aim of the study was to assess and evaluate the antimicrobial effectiveness of chitosan nanoparticles (CSNPs) with calcium hydroxide in the elimination of Enterococcus faecalis. Materials and Methods: Using the broth microdilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of calcium hydroxide and CSNPs were measured. The antibiofilm effect of calcium hydroxide and CSNPs against E. faecalis biofilm was qualitatively analyzed using a crystal violet assay. A 7-day-old biofilms of E. faecalis grown on dentine discs were assigned to the following three groups (n = 11 dentine discs), normal saline (group I), calcium hydroxide (group II), and CSNPs (group III). Quantification of live and dead cells using confocal microscopy was done to evaluate the antibiofilm efficacy of the medicaments included in the study. Results: MIC of calcium hydroxide and CSNPs against E. faecalis was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. MBC of calcium hydroxide and CSNPs was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. Using Crystal Violet (CV) assay, calcium hydroxide and CSNPs showed biofilm inhibition at concentrations of 2.5 mg/mL and 0.625 mg/mL, respectively. Confocal laser scanning microscopy analysis found that both calcium hydroxide and CSNPs showed a significant decrease in viable cells at their MBC values compared to the control group’s normal saline. CSNPs showed a significantly lower percentage of live cells than calcium hydroxide (P < 0.05). Conclusion: The study results reveal that the antimicrobial efficacy of CSNPs is better than calcium hydroxide and normal saline against E. faecalis biofilm.

Antibacterial Properties of Fucoidan from Thirteen Indian Brown Seaweeds against Various Pathogenic Bacteria

The present study aimed to evaluate the antibacterial properties of hot water extracted fucoidan from thirteen Indian brown seaweeds against various pathogenic bacteria. The agar-well diffusion method was used to assess the antibacterial test of different fucoidan. The results revealed that S. vulgare fucoidan had higher antibacterial activity against many pathogenic bacteria, while fucoidan from other brown seaweeds had the least or no antibacterial activity in comparison to S. vulgare fucoidan. Therefore, we evaluated the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and brine shrimp toxicity assay in S. vulgare fucoidan. The MIC and MBC values were found to be 1.25 mg/mL and 10 mg/mL in S. vulgare fucoidan against pathogenic bacteria. S. vulgare fucoidan were found to be nontoxic as no mortality (Artemia) was found at different fucoidan concentrations. In addition, characterizations such as ultraviolet-visible spectroscopy, fourier-transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy were studied in Sargassum vulgare fucoidan and revealed the properties of fucoidan. This study revealed that hot water extracted fucoidan may have other biological activities but not antibacterial action. Furthermore, studies may reveal the mode of action in fucoidan.

Influence of critical micelle concentration of choline-based long chain fatty acid soaps on their antibacterial activity against Methicillin resistant Staphylococcus aureus

HypothesisAntimicrobial resistance (AMR) is a pressing global health concern. ESKAPEE pathogens, such as Methicillin-resistant Staphylococcus aureus (MRSA) are notable of concern in healthcare settings due to their resistance to critical antibiotics. To combat AMR, the development of alternatives such as bacterial membrane-active agents is crucial. Fatty acids (FAs) have emerged as a sustainable, antibiotic-free solution with inherent antibacterial activity. However, long chain saturated fatty acids (LCFAs) sodium soaps exhibit poorly antibacterial properties in comparison to short chain FAs, believed to be linked to limited solubility in aqueous media. ExperimentsWe employed choline as a chaotropic organic counter-ion to enhance the solubility of LCFAs and investigated their antibacterial effects against MRSA. The optimal medium conditions for micelle formation for LCFAs was first investigated. Then, we determined the critical micelle concentration (CMC), micellar morphology, and aggregation number through surface tension measurements and small angle neutron scattering experiments. Antimicrobial activity was assessed using minimum bactericidal concentration (MBC) assays and time-kill experiments. FindingsWe have identified conditions where LCFAs are effective against MRSA for the first time, providing valuable insights for developing new antibacterial agents to fight AMR. LCFAs need to be used above their Krafft temperatures and CMC to exhibit antibacterial efficacy.

Antimicrobial Activity of Formulated Origanum and Thyme Essential Oil Nanoemulsions - A Comparative Study

Introduction: This study focused on the formulation processing and antimicrobial activities of Origanum and Thyme essential oils (OEO) (TEO) and their nanoemulsions (OEON) (TEON) on gram-positive and gram-negative bacteria and yeast. Optimal nanoemulsion formulation and stability were achieved through balancing between requisite hydrophilic-lipophilic balance (rHLB) and surfactant concentration (Smix) of nanoemulsions. Methods: The smallest droplet sizes of OEON: (z -185.1 nm ± 0.85) and TEON (z -130.1 nm ± 0.60), were achieved by using 10 g/100 mL of OEO and TEO with 15 g/100 mL Smix at ultrasonication for 2 min with no phase separation. The size of nanoemulsion droplet and PDI was found to be influenced by HLB value, treatment time, and Smix concentration. Antimicrobial analyses, including a zone of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill kinetics assay, were performed against Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae. Results: The antimicrobial findings demonstrated that OEO exhibited higher antimicrobial activity compared to TEO (P<0.05). Meanwhile, the OEON and TEON substantially reduced the MIC and MBC values, compared to OEO and TEO against all tested microorganisms (P<0.05). Throughout the time-kill assay, E. coli was reduced by 5 log CFU/ml within 120 minutes, while S. cerevisiae and S. aureus were eradicated after 60 and 120 minutes of incubation with OEON, respectively. Conclusion: In turn, TEON reduced E. coli by 5 log CFU/ml and S. cerevisiae by 4 log CFU/ml within 120 minutes, while S. aureus was inhibited within the same time of incubation with TEON. The nanoemulsion formulations of OEO and TEO considerably enhanced the antimicrobial properties, which provides a promising alternative plant-derived antimicrobial for pharmaceuticals and food applications.

Effect of Nigella sativa L. essential oil on oxidative stability and microbial growth of local white Feta cheese

Controlling the development of pathogenic and spoilage microorganisms is critical for food manufacturers to preserve their products. Cheese provides favourable conditions for microbial growth and oxidative degradation due to the presence of water, fat, protein, and minerals. The present work thus aimed to determine the influence of Nigella sativa L. essential oil on microbial growth and oxidative stability of cheese made from fresh milk. The analysis of the chemical composition of N. sativa essential oil was performed by gas chromatography-mass spectrometry. The main compounds detected were 9,12-octadecadienoic acid (27.96%), cis-vaccenic acid (20.69%), 6-epi-shyobunol (7.08%), benzene, 1-methyl-3-(1-methylethyl)- (6.33%), n-hexadecanoic acid (3.86%), o-cymene (2.77%), and cis-4-methoxy thujane (2.71%). The antioxidant activity of N. sativa essential oil was calculated by the 2,2-diphenyl-1-picrylhydrazyl method with IC50 = 8.08 μg/mL. The microdilution test showed that the minimum inhibitory concentration (MIC) of N. sativa essential oil for all pathogens was 500 μg/mL, while the minimum bactericidal concentration (MBC) was 1,000 μg/mL for Staphylococcus aureus and Bacillus cereus, and 2,000 μg/mL for Escherichia coli and Pseudomonas aeruginosa. The physicochemical properties of the cheese showed that the addition of essential oil did not affect the dry matter, but increased the pH, decreased the % acidity, and decreased the peroxide value compared to the control sample (sample without essential oil). In addition, the essential oil reduced the bacterial and fungal counts of the cheese compared to the control sample, and affected the sensory characteristics of the cheese during the 90-day storage period. Results also showed that the addition of 0.5% essential oil of N. sativa not only prevented microbial growth and oxidative degradation, but also improved the taste and overall acceptability of cheese.

Green algae-produced multimer cathelicidin-RC1 disrupts membrane integrity for inhibiting bacterial growth

Cathelicidin-RC1, extracted from the bullfrog Rana catesbeiana, has been found to effectively combat gram-negative bacteria but has limited inhibitory effects on gram-positive bacteria. Additionally, the specific mechanism of cathelicidin-RC1’s interaction with bacteria remains unclear. In this research, we present the expression analysis of a chimeric peptide composed of three repetitive units of cathelicidin-RC1 (3×cathelicidin-RC1) with a hemagglutinin (HA) and a 6×His tag attached at its C-terminus in Chlamydomonas reinhardtii, leading to the production of a chimeric peptide with a molecular mass of ~16.2kDa. The recombinant peptide, 3×cathelicidin-RC1-HA-6×His, demonstrates a wide range of antimicrobial activity, with minimum inhibitory concentration (MIC) values of approximately 20~30µg/ml and 10~60µg/ml against gram-positive and negative bacteria, respectively. The minimum bactericidal concentration (MBC) values of 3×cathelicidin-RC1-HA-6×His varies from 1× to 3×MIC. Furthermore, 3×cathelicidin-RC1-HA-6×His demonstrates excellent stability, pH stability, and resistance to digestion by certain proteases. It also exhibits low cytotoxicity and negligible hemolytic activity against rat erythrocytes. Scanning electron microscopy and propidium iodide analysis indicate that 3×cathelicidin-RC1-HA-6×His disrupts bacterial cell membranes, leading to inhibition of bacterial growth. Overall, our findings demonstrate that 3×cathelicidin-RC1-HA-6×His, produced in the heterologous expression host C. reinhardtii, effectively inhibits bacterial growth and holds great promise for potential application.

Potential of Cosmos caudatus Kunth. extract as natural food sanitiser

Bacterial growth in food sources after harvesting and during food manufacturing has emerged as a major agricultural concern. Currently, several chemical preservatives have been added to foods to prevent or inhibit bacterial growth. These phenomena, however, become a concern when consumers begin to demand the safety of the food they consume, thus resulting in a search for natural plant extracts as an alternative. The antimicrobial activity of Cosmos caudatus leaf extract against six food pathogens was thus investigated in the present work. The disc-diffusion test, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) tests were used to determine the antibacterial potential. Time-kill kinetics were used to determine their killing endpoints at various incubation times. Thereafter, Bacillus cereus was selected as a representative bacterium to be viewed under the light sheet electron microscope (LSEM) to observe the morphological changes. For the application as a sanitiser, different concentrations of C. caudatus extract were applied to chicken meat and oyster mushroom to determine bacterial reduction and sensory acceptability. The toxicity test using brine shrimp lethality assay was also performed to determine the toxicity level of C. caudatus extract. Results showed that C. caudatus extract contain five major peaks of flavonoids. In the antibacterial test, all tested pathogens were inhibited, with B. cereus being the most susceptible, with a significant reduction time of more than 3 log10 at 3.125 mg/mL. Under LSEM, the population of B. cereus was reduced, and the shape was wrinkled. In the application, C. caudatus extract at 0.05% for 5 min treatment time was chosen as the best formulation, whereas the brine shrimp tests showed that C. caudatus extract was safe for human consumption (LC50: 3.54 mg/mL). In conclusion, C. caudatus extract could have the potential to be further explored as a natural food sanitiser.

Evaluation of anti-microbial activity of biotite and biotite composite based on crystallographic parameters: Estimation of crystallite size employing X-ray diffraction data

This study dealt with naturally occurring biotite from the river sediment to synthesize biotite based composite to evaluate antimicrobial activities against gram positive bacteria, negative bacteria and fungi. Biotite mineral, and synthesized carbon aerogel –biotite (CBt) composite and carbon aerogel-biotite –ZnO (CBtZ) composites were considered for the antimicrobial study. The samples were characterized by X-ray diffraction technique and different crystallographic parameters were computed applying X-ray diffraction data. Also, FESEM was performed to understand the surface morphology of the samples. Crystal size of the biotite, CBt and CBtZ were computed 103.215, 57.567, and 36.496 nm respectively. Tabulated microstrain are 0.175, 0.499 and 0.935 for the biotite, CBt and CBtZ respectively. Various models and equations were used to justify crystallite size, including the Williamson-Hall plot, linear straight line model, Scherrer equation, Monshi-Scherrer model, Size-strain plot (SSP) model, Halder-Wagner method and Sahadat-Scherrer model. For the both composite samples, following models confirmrd the presence of nanocrystal with a range of 50.789 -97.777 nm (CBt) and 36.496-105.843 nm(CBtZ). However, for the biotite, all mentioned models were proved invalid except scherrer equation, SSP model and Monshi-Scherrer model. Linear straight line model was found invalid to calculate crystallite size of the three samples. Moreover, different crystal parameters like dislocation density, volume of the unit cell, lattice parameters were computed. Zone of inhabitation estimation method was employed to estimate antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus, Salmonella abony, Escherichia coli and Candida albicans. Required minimum inhibitory concentration (MIC) together with minimum bactericidal concentration (MBC) also estimated in this study. Crystal size effect on the antimicrobial activities of the samples were evaluated in this study.

Comparative evaluation of minimal inhibitory concentration and minimal bactericidal concentration of various herbal irrigants against Enterococcus faecalis

Context: The purpose of this article is to evaluate the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of Herbal Irrigants. Aim: The aim of the study was to evaluate MIC and MBC of herbal extracts of Azadirachta indica, Curcuma longa, and Green Tea Against Enterococcus faecalis. Methodology: The MIC and MBC of extracts of A . indica (neem), C. longa (turmeric), and Green Tea were evaluated to establish them as standard root canal irrigants against E. faecalis using agar well diffusion method. Statistical Analysis Used: The collected data were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software. Results: The present study found that green tea exhibited the most substantial antimicrobial activity among the tested herbal extracts, which was comparable to chlorhexidine. Although A. indica and C. longa required higher concentrations for effectiveness, their antimicrobial properties were also apparent. Conclusions: Within the constraints of this study, it can be concluded that green tea could be considered a promising alternative to chlorhexidine in treating endodontic infections due to its substantial antimicrobial activity against E. faecalis at lower concentrations.

Antibacterial behavior and mechanism of nitrogen, silicon-doped amphiphilic carbon dots

A new kind of amphiphilic carbon dots (CDs) was prepared with citric acid and silane coupling agent as raw materials. Due to the doping of nitrogen and silicon elements, the surface of CDs contains not only oxygen-containing functional groups, but also alkyl hydrophobic chains, showing amphiphilic characteristic. The micro molecular structure and elemental composition of CDs were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and other tests. The antibacterial behavior of CDs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was studied by the disk antibacterial method, plate colony, scanning electron microscopy (SEM) and other methods. The biocompatibility of CDs was evaluated by cytotoxicity and hemolysis in vitro. The results proved that CDs possessed the average particle size of 1.75 nm and the negative surface potential of −2.71 mV. For E. coli and S. aureus, the minimum bactericidal concentrations of CDs were 500 μg/mL and 400 μg/mL, respectively. These co-doped CDs also possessed the ability to inhibit biofilm formation. The antibacterial mechanism was mainly through the adsorption force to rupture the bacterial membrane and induce the generation of reactive oxygen species in bacterial cells. In addition, CDs exhibited excellent biocompatibility because of their low cytotoxicity and hemolysis, indicating that they can be used as a new material in the antibacterial field.

Potensi Antimikroba dan Antioksidan Beberapa Ekstrak Daun Benalu (Scurrula ferruginea (Roxb. ex Jack) Danser dari Archidendron sp. terhadap Staphylococcus aureus, Escherichia coli, dan Candida albicans

Scurrula ferruginea (Roxb. ex Jack) Danser is known for its role as an antimicrobial and antioxidant agent due to its content of phenolic compounds, alkaloids, and terpenoids. S. ferruginea has been widely used in traditional medicine for skin infections, diarrhea, hypertension, and digestive tract diseases. This study aims to determine the antimicrobial and antioxidant potential of various treatments of S. ferruginea mistletoe extracts. The experimental method used in this research is the nested pattern experiment. The extract treatments applied include fresh extract, boiled dry extract, boiled fresh extract, brewed dry extract, and brewed fresh extract. Antimicrobial potential was assessed using disc diffusion and dilution methods. Antioxidant activity (IC50) was determined using the DPPH (1,1-Diphenyl-2-Picryl-Hydrazine) method, and Total Phenolic Content (TPC) was also determined. The results indicate that the highest antimicrobial activity against Escherichia coli and Staphylococcus aureus was found in the strong category of fresh extract treatment, whereas there was no significant effect on Candida albicans growth. The fresh extract treatment exhibited the highest antimicrobial activity with a total phenolic content of 20.77321 mgGAE/mL. The Minimum Inhibitory Concentration (MIC) values for the fresh extract against S. aureus and E. coli were 6.25%, and the Minimum Bactericidal Concentration (MBC) values were 12.5% against both bacteria. The antioxidant value of the fresh extract was 101.26 μg/mL, categorized as moderate. Based on the conducted research, it can be concluded that S. ferruginea leaf extract can inhibit the activities of S. aureus and E. coli, while showing no effect on Candida albicans growth.

A New Guanidine-Core Small-Molecule Compound as a Potential Antimicrobial Agent against Resistant Bacterial Strains.

The guanidine core has been one of the most studied functional groups in medicinal chemistry, and guanylation reactions are powerful tools for synthesizing this kind of compound. In this study, a series of five guanidine-core small molecules were obtained through guanylation reactions. These compounds were then evaluated against three different strains of Escherichia coli, one collection strain from the American Type Culture Collection (ATCC) of E. coli ATCC 35218, and two clinical extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates (ESBL1 and ESBL2). Moreover, three different strains of Pseudomonas aeruginosa were studied, one collection strain of P. aeruginosa ATCC 27853, and two clinical multidrug-resistant isolates (PA24 and PA35). Among Gram-positive strains, three different strains of Staphylococcus aureus, one collection strain of S. aureus ATCC 29213, and two clinical methicillin-resistant S. aureus (MRSA1 and MRSA2) were evaluated. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) experiments were reported, and the drop plate (DP) method was used to determine the number of viable suspended bacteria in a known beaker volume. The results from this assessment suggest that guanidine-core small molecules hold promise as therapeutic alternatives for treating infections caused by clinical Gram-negative and Gram-positive bacteria, highlighting the need for further studies to explore their potential. The results from this assessment suggest that the chemical structure of CAPP4 might serve as the basis for designing more active guanidine-based antimicrobial compounds, highlighting the need for further studies to explore their potential.

Synthesis, characterization,photocatalyticand bactericidal propertiesof Ag3PO4/NiCo-metal–organic framework composite irradiated by white light emitting diode

In this paper, Ag3PO4/NiCo-MOF composites were synthesized with different mass contents of NiCo-MOF (5, 10, and 20wt%) from silver phosphate crystals (Ag3PO4) and sheets of metal–organic frameworks of nickel and cobalt (NiCo-MOF). The materials were characterized, and their photocatalytic and bactericidal properties were evaluated against the bacteria Staphylococcus aureus (S. aureus) and Escherichia coli (E coli) incubated under exposure to white light emitting diode (WLED). X-ray diffraction (XRD) patterns of Ag3PO4 and NiCo-MOF confirm the formation of crystals without a deleterious phase. Field emission scanning electron microscopy (FE-SEM) images showed polymorphism with shape predominant to tetrahedron-like Ag3PO4 microcrystals and sheets for NiCo-MOF. The materials showed band gap energy values between 2.32 eV and 3.60 eV. Fourier-transform infrared (FTIR) spectroscopy shows the formation of molecular interaction between the materials. Bacterial susceptibility tests showed a reduction in Minimum Bactericidal concentration (MBC) values to 64 μg/mL when incubated with Ag3PO4 under WLED exposure. The Ag3PO4/NiCoMOF-5wt% composite, incubated without light, showed MBC values of 64 μg/mL for S. aureus and 32 μg/mL for E. coli, respectively. Based on the results, the composite in the absence of WLED showed superior bactericidal results.

An In-vitro Antioxidant and Antimicrobial Activity of Vitis vinifera Leaf Extract

Background: Vitis vinifera (Flame red grape) is known for its hepatoprotective, nephroprotective and cardioprotective activity of ethanolic and aqueous extracts of aerial parts has been reported but, due to presence of polyphenols, glycosides, saponins and alkaloid, the antioxidant and antimicrobial activity yet not to evaluated on salad plant and bacteria, respectively. Aim: This research examined grape (V. vinifera flaming red) leaf ethanolic extract (EE) as a bioactive resource. Methods: Ethanolic extract test, primarily to calculate the overall phenolic content by using the Folin-Ciocalteu technique and gallic acid taking as a reference. Similarly, flavonoid content measured using quercetin as a calibration curve. Antioxidant properties was confirmed by getting positive responses from different methods (DPPH, H2O2, FRAP and Phospho-Molybdenum). Antimicrobial activity tested against gram-positive bacteria (Lactobacillus cereus and Staphylococcus aureus) and gramnegative bacteria (Escherichia coli and Staphylococcus enterica ser. Typhimurium) in a broth microdilution test. The ethanolic extract (EE) are rich in antioxidant-rich phenolic compounds show minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) for every given bacterium on beetroot and spinach leaves. Results: We investigate this extract’s total phenol, total flavonoid, and antioxidant and antibacterial properties. We also identify its main phenolic components, revealing its phytochemical diversity. We found that the EE had 39.29 gGAkg-1 dw of phenol and 96.05 gQE kg-1 dw of flavonoids. The EE scavenges DPPH, H2O2, FRAP, and PM radicals at 142, 168, 275, and 172 g TE kg-1, respectively. We reveal the complex character of this extract by revealing catechins, flavonoids, tannins, malic acid, enzymes, resveratrol, phenolic acids, flavonols, procyanidins, and anthocyanins. Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus are all inhibited by EE with a MIC range of 16 to 18 gL-1 (E. coli). The extract affects bacterial growth at different stages. The EE reduces spinach and beetroot leaf total bacterial load by 1.159 to 2.456 log drop when used as a sanitizer at 25 gL-1 (1.156–2.858 log reduction). Conclusion: This research work highlights grape leaf EE as a novel and appealing source of bioactive components with its strong antibacterial and antioxidant activities against common foodborne infectious agents. Our research reveals that leaf ethanolic extract could reduce human pathogenic microorganisms in fresh green vegetables, improving food safety.

An In-vitro Antioxidant and Antimicrobial Activity of Vitis vinifera Leaf Extract

Background: Vitis vinifera (Flame red grape) is known for its hepatoprotective, nephroprotective and cardioprotective activity of ethanolic and aqueous extracts of aerial parts has been reported but, due to presence of polyphenols, glycosides, saponins and alkaloid, the antioxidant and antimicrobial activity yet not to evaluated on salad plant and bacteria, respectively. Aim: This research examined grape (V. vinifera flaming red) leaf ethanolic extract (EE) as a bioactive resource. Methods: Ethanolic extract test, primarily to calculate the overall phenolic content by using the Folin-Ciocalteu technique and gallic acid taking as a reference. Similarly, flavonoid content measured using quercetin as a calibration curve. Antioxidant properties was confirmed by getting positive responses from different methods (DPPH, H2O2, FRAP and Phospho-Molybdenum). Antimicrobial activity tested against gram-positive bacteria (Lactobacillus cereus and Staphylococcus aureus) and gramnegative bacteria (Escherichia coli and Staphylococcus enterica ser. Typhimurium) in a broth microdilution test. The ethanolic extract (EE) are rich in antioxidant-rich phenolic compounds show minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) for every given bacterium on beetroot and spinach leaves. Results: We investigate this extract’s total phenol, total flavonoid, and antioxidant and antibacterial properties. We also identify its main phenolic components, revealing its phytochemical diversity. We found that the EE had 39.29 gGAkg-1 dw of phenol and 96.05 gQE kg-1 dw of flavonoids. The EE scavenges DPPH, H2O2, FRAP, and PM radicals at 142, 168, 275, and 172 g TE kg-1, respectively. We reveal the complex character of this extract by revealing catechins, flavonoids, tannins, malic acid, enzymes, resveratrol, phenolic acids, flavonols, procyanidins, and anthocyanins. Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus are all inhibited by EE with a MIC range of 16 to 18 gL-1 (E. coli). The extract affects bacterial growth at different stages. The EE reduces spinach and beetroot leaf total bacterial load by 1.159 to 2.456 log drop when used as a sanitizer at 25 gL-1 (1.156–2.858 log reduction). Conclusion: This research work highlights grape leaf EE as a novel and appealing source of bioactive components with its strong antibacterial and antioxidant activities against common foodborne infectious agents. Our research reveals that leaf ethanolic extract could reduce human pathogenic microorganisms in fresh green vegetables, improving food safety.

In Vitro Methods for Assessing the Antibacterial and Antibiofilm Properties of Essential Oils as Potential Root Canal Irrigants-A Simplified Description of the Technical Steps.

Essential oils have gained in significance due to their various biological activities, and there is a growing demand for them in many industries. The present article focuses on the technical steps for an in vitro evaluation of the antibacterial and antibiofilm activities of essential oils for potential use as root canal irrigant in dentistry. The bioactivities of the essential oil were investigated through in vitro assays. The gram-positive bacterium Enterococcus faecalis was used as a micro-organism model. The antibacterial activity of the essential oil was assessed using the microdilution method, and resazurin staining to determine the minimal inhibition concentrations (MICs) and the minimal bactericidal concentrations (MBCs). The antibiofilm effect was evaluated spectrophotometrically at 570 nm using the microplate cultivation technique and crystal violet staining. This article features a detailed in vitro protocol to facilitate the preparation of the essential oil samples, the bacterial suspension, and the methods used for assessment of the antibiofilm and antibacterial activities of the essential oil. The advantages of these approaches are presented in relation to the limits linked to the choice of the bacteria and the essential oil.

Development and Evaluation of Bioconverted Milk with Anti-Microbial Effect against Periodontal Pathogens and α-Glucosidase Inhibitory Activity.

To decrease periodontal pathogens and increase the number of beneficial bacteria, probiotics and bioactive compounds made via microbial bioconversion are recently used. In addition, the interest regarding probiotics-mediated bioconversion with popular medicinal plants is increasing. Artemisia herba-alba, a type of wormwood, has recently been attention as a medicinal plant due to its various bioactive compounds. Therefore, we developed bioconverted milk containing A. herba-alba that effectively inhibited periodontal pathogens and α-glucosidase. To select the appropriate lactic acid bacteria for the probiotic candidate strain, 74 strains of lactic acid bacteria were screened. Among them, Lactiplantibacillus plantarum SMFM2016-RK was chosen as the probiotic due to its beneficial characteristics such as high acid and bile tolerance, antioxidant activity, and α-glucosidase inhibition. Based on the minimal bactericidal concentration against three periodontal pathogens, the following appropriate concentrations of Artemisia herba-alba extract were added to milk: 5 mg/mL of A. herba-alba ethanol extract and 25 mg/mL of A. herba-alba hot-water extract. Four bioconverted milks (BM), BM1, BM2, BM3, and BM4, were produced by combining L. plantarum SMFM2016-RK alone, L. plantarum SMFM2016-RK and ethanol extract, L. plantarum SMFM2016-RK and hot-water extract, and L. plantarum SMFM2016-RK with both extracts. As a result of antimicrobial activity, BM3 inhibited the growth of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis the most, and BM4 suppressed the growth of Fusobacterium nucleatum the most. In addition, bioconverted milk containing A. herba-alba (BM2, BM3, and BM4) inhibited α-glucosidase more effectively than BM1. The whole genome of L. plantarum SMFM2016-RK was obtained, and 3135 CDS, 67 tRNA, and 16 RNA were predicted. The genome annotation of L. plantarum SMFM2016-RK revealed 11 CDS related to proteolysis and amino acid metabolism and 2 CDS of phenolic acid-metabolizing enzymes. In conclusion, A. herba-alba-added milk bioconverted by L. plantarum SMFM2016-RK displayed both the growth inhibitory effect on periodontal pathogens and the α-glucosidase inhibitory activity; thus, it necessitates to evaluate the effects on the alleviation of periodontal diseases and glycemic control through future animal experiments.