Potent Antimicrobial Activity Research Articles

Biodegradable plastic formulated from chitosan of Aristeus antennatus shells with castor oil as a plasticizer agent and starch as a filling substrate

Biodegradable plastics are those subjected easily to a degradation process, in which they can be decomposed after disposal in the environment through microbial activity. 30 bioplastic film formulations based only on chitosan film were used in the current investigation as a positive control together with chitosan film recovered from chitin-waste of locally obtained Aristeus antennatus. Additionally, castor oil was used as a plasticizer. While the yield of chitosan was 18% with 7.65% moisture content and 32.27% ash in the shells, the isolated chitin had a degree of deacetylation (DD) of 86%. The synthesized bioplastic films were characterized via numerous criteria. Firstly, the swelling capacity of these biofilms recorded relatively high percentages compared to polypropylene as synthetic plastic. Noticeably, the FTIR profiles, besides DSC, TGA, and XRD, confirmed the acceptable characteristics of these biofilms. In addition, their SEM illustrated the homogeneity and continuity with a few straps of the chitosan film and showed the homogeneous mixes of chitosan and castor oil with 5 and 20%. Moreover, data detected the antibacterial activity of different bioplastic formulas against some common bacterial pathogens (Enterococcus feacalis, Kelbsiella pnumina, Bacillus subtilis, and Pseudomonas aeruginosa). Amazingly, our bioplastic films have conducted potent antimicrobial activities. So, they may be promising in such a direction. Further, the biodegradability efficacy of bioplastic films formed was proved in numerous environments for several weeks of incubation. However, all bioplastic films decreased in their weights and changed in their colors, while polypropylene, was very constant all the time. The current findings suggest that our biofilms may be promising for many applications, especially in the field of food package protecting the food, and preventing microbial contamination, consequently, it may help in extending the shelf life of products.

LL37 Microspheres Loaded on Activated Carbon-chitosan Hydrogel: Anti-bacterial and Anti-toxin Wound Dressing for Chronic Wound Infections.

Antimicrobial peptide LL37 is a promising antibacterial candidate due to its potent antimicrobial activity with no known bacterial resistance. However, intrinsically LL37 is susceptible to degradation in wound fluids limits its effectiveness. Bacterial toxins which are released after cell lysis are found to hinder wound healing. To address these challenges, encapsulating LL37 in microspheres (MS) and loading the MS onto activated carbon (AC)-chitosan (CS) hydrogel. This advanced wound dressing not only protects LL37 from degradation but also targets bacterial toxins, aiding in the healing of chronic wound infections. First, LL37 MS and LL37-AC-CS hydrogel were prepared and characterised in terms of physicochemical properties, drug release, and peptide-polymer compatibility. Antibacterial and antibiofilm activity, bacterial toxin elimination, cell migration, and cell cytotoxicity activities were investigated. LL37-AC-CS hydrogel was effective against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. LL37-AC-CS hydrogel bound more endotoxin than AC with CS hydrogel alone. The hydrogel also induced cell migration after 72h and showed no cytotoxicity towards NHDF after 72h of treatment. In conclusion, the LL37-AC-CS hydrogel was shown to be a stable, non-toxic advanced wound dressing method with enhanced antimicrobial and antitoxin activity, and it can potentially be applied to chronic wound infections to accelerate wound healing.

Exploring the pharmacological significance of Murraya koenigii (L.) Spreng: Insights from North-East India

Murraya koenigii (L.) Spreng., is a renowned medicinal and aromatic plant having antimicrobial and broad biological activities. In the present study, the essential oil chemical profile of the leaf and floral part were analysed using GC-FID and GC-MS, and the antimicrobial activities were determined by disk diffusion assay. The scientific analysis revealed α-pinene (40.41%) was the major compound of leaf essential oil (MKL) followed by sabinene (29.66%), β-pinene (7.92%), caryophyllene (4.24%), limonene (3.39%), terpinen-4-ol (3.25%), γ-terpinene (2.63%), terpinolene (1.58%), linalool (1.32%), along with other trace components. The floral part (MKF) contains the compounds α-pinene (74.02%) as the major compound followed by β-pinene (7.17%), sabinene (5.72%), limonene (4.19%), β-myrcene (1.98%), γ-terpinene (1.47%) and terpinen-4-ol (1.41%) along with other trace compounds. The MIC result revealed essential oil showed effectiveness against Escherichia coli (40 μg/mL), Micrococcus luteus (80 μg/mL), Aspergillus fumigatus (60 μg/mL) and Aspergillus brasiliensis (80 μg/mL) for MKL while MKF did not exhibit potent antimicrobial activities. The essential oils revealed potent antioxidant potential as determined by DPPH method with IC50 values of 14.02 μL/mL (MKL) and 5.45 μL/mL (MKF) and the ABTS method with IC50 values of 5.07 μL/mL and 8.38 μL/mL in MKL and MKF respectively as compared to that of the standards. The essential oils revealed potent antidiabetic activity with 6.02 μL/mL (MKL) and 8.18 μL/mL (MKF) as that of the standard. However, both MKL and MKF were not much effective in protease inhibitory activity and anti-tyrosinase activity. The study results exhibited a potent bioactivity profile and revealed many new utilization aspects of this essential oil.

Efficacy of Honey-Based Wound Dressing Versus Hydrogel-Based Wound Dressing in Wound Healing Process: A Literature Review

Introduction: Wound dressing is a fundamental aspect of modern healthcare, encompassing a diverse range of materials and techniques aimed at optimizing the healing process while safeguarding against infection and further injury. By understanding the specific benefits of different types of wound dressings, healthcare professionals can optimize the healing process and improve patient outcomes Methods: This literature review was compiled using information from various open access online databases. Data were collected and analyzed. Results and Discussions: Honey dressing demonstrates superior efficacy compared to hydrogel dressing in wound management. Its multifaceted properties, such as potent antimicrobial activity, tissue regeneration promotion, and anti-inflammatory effects, render it a superior option for wound healing throughout all stages. Additionally, honey is more cost-effective than hydrogel and more easily accessible. Conclusion: The efficacy of honey dressing surpasses that of hydrogel dressing in wound management. Honey's multifaceted properties, including its potent antimicrobial activity, ability to promote tissue regeneration, and anti-inflammatory effects, make it a superior choice for wound healing across all phases.

Peptide-AIE Nanofibers Functionalized Sutures with Antimicrobial Activity and Subcutaneous Traceability.

As one of the most widely used medical device, sutures face challenges related to surgical site infections (SSIs) and lack of subcutaneous traceability. In the present study, we have developed a facile and effective approach using peptide-AIE nanofibers (NFs-K18) to create fluorescent-traceable antimicrobial sutures, which have been applied to four commercially available sutures. The functionalized sutures of PGAS-NFs-K18 and PGLAS-NFs-K18 exhibited fluorescence with excellent penetration from 4mm chicken breasts. They also demonstrated remarkable stability after 24h of white light illumination and threading through chicken breasts 10 times. These sutures efficiently generated ROS, resulting in a significant suppression of four clinical bacteria, with the highest antimicrobial rate of nearly 100%. Moreover, the sutures exhibited favorable hemocompatibility and biocompatibility. In vivo experiments demonstrated that the optimized PGLAS-NFs-K18 suture displayed potent antimicrobial activity against MRSA, effectively inhibiting inflammation and promoting tissue healing in both skin wound and abdominal wall wound models, outperforming the commercially available Coated VICRYL® Plus Antibacterial suture. Importantly, PGLAS-NFs-K18 exhibited sensitive subcutaneous traceability, allowing for accurate in situ monitoring of its degradation. We believe that this straightforward strategy offers a new pathway for inhibiting SSIs and monitoring the status of sutures. This article is protected by copyright. All rights reserved.

Developmental Formulation Principles of Food Preservatives by Nanoencapsulation-Fundamentals, Application, and Challenges.

The role of food additives is to preserve food by extending shelf life and limiting harmful microorganism proliferation. They prevent spoilage by enhancing the taste and safety of food by utilizing beneficial microorganisms and their antimicrobial metabolites. Current advances in food preservation and processing utilize green technology principles for green preservative formulation, enhancing nutrition and supplying essential micronutrients safely, while also improving quality, packaging, and food safety. Encapsulation is gaining attention for its potential to protect delicate materials from oxidative degradation and extend their shelf life, thereby ensuring optimal nutrient uptake. Nanoencapsulation of bioactive compounds has significantly improved the food, pharmaceutical, agriculture, and nutraceutical industries by protecting antioxidants, vitamins, minerals, and essential fatty acids by controlling release and ensuring delivery to specific sites in the human body. This emerging area is crucial for future industrial production, improving the sensory properties of foods like color, taste, and texture. Research on encapsulated bioactive compounds like bacteriocins, LAB, natamycin, polylysine, and bacteriophage is crucial for their potential antioxidant and antimicrobial activities in food applications and the food industry. This paper reviews nanomaterials used as food antimicrobial carriers, including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers, to protect natural food antimicrobials from degradation and improve antimicrobial activity. This review discusses nanoencapsulation techniques for biopreservative agents like nisin, poly lysine, and natamycin, focusing on biologically-derived polymeric nanofibers, nanocarriers, nanoliposomes, and polymer-stabilized metallic nanoparticles. Nanomaterials, in general, improve the dispersibility, stability, and availability of bioactive substances, and this study discusses the controlled release of nanoencapsulated biopreservative agents.

Enhancing the stability and therapeutic potential of the antimicrobial peptide Feleucin-K3 against Multidrug-Resistant a. Baumannii through rational utilization of a D-amino acid substitution strategy

Antimicrobial peptides (AMPs), which have a low probability of developing resistance, are considered the most promising antimicrobial agents for combating antibiotic resistance. Feleucin-K3 is an amphiphilic cationic AMP that exhibits broad-spectrum antimicrobial activity. In our previous research, the first phenylalanine residue was identified as the critical position affecting its biological activity. Here, a series of Feleucin-K3 analogs containing hydrophobic D-amino acids were developed, leveraging the low sensitivity of proteases to unnatural amino acids and the regulatory effect of hydrophobicity on antimicrobial activity. Among them, K-1dF, which replaced the phenylalanine of Feleucin-K3 with its enantiomer (D-phenylalanine), exhibited potent antimicrobial activity with a therapeutic index of 46.97 and MICs between 4 to 8 μg/ml against both sensitive and multidrug-resistant Acinetobacter baumannii. The introduction of D-phenylalanine increased the salt tolerance and serum stability of Feleucin-K3. Moreover, K-1dF displayed a rapid bactericidal effect, a low propensity to develop resistance, and a synergistic effect when combined with antibiotics. More importantly, it exhibited considerable or superior efficacy to imipenem against pneumonia and skin abscess infection. In brief, the K-1dF obtained by simple and effective modification strategy has emerged as a promising candidate antimicrobial agent for tackling multidrug-resistant Acinetobacter baumannii infections.

Isolation and characterization of Bacillus subtilis RZS-01 isolate from agricultural soil in Bangladesh with potent antimicrobial activities

Isolation and characterization of Bacillus subtilis RZS-01 isolate from agricultural soil in Bangladesh with potent antimicrobial activities

A facile microwave assisted synthesis of thymohydroquinone with antibiofilm properties against Salmonella typhi and Listeria monocytogenes

Thymoquinone (TQ), a monoterpene isolated from the Nigella sativa L. seeds using the oil expeller method, gave about 40% of the total oil. Clevenger hydrodistillation of the obtained oil yielded volatile oil (0.55%) with 30% of TQ. Subsequent purification through silica gel column chromatography resulted in the isolation of pure TQ. The microwave assisted reduction of TQ with zinc and acetic acid resulted in the formation of thymohydroquinone within 5 min (THQ, yield 85%). The conventional reduction method gives 42% - 60% yield and is found to be time-consuming (4-12 h). The prepared THQ was tested at various concentrations for the inhibition of planktonic as well as biofilm of Listeria monocytogenes Scott A and Salmonella typhi FB231 bacterial cultures. Minimum inhibitory concentration (MIC) using MTT assay showed 50 μg/mL and 100 μg/mL for L. monocytogenes and S. typhi, respectively. Further, the biofilm growth inhibition and development were assessed using a crystal violet (CV) assay, which confirmed that THQ and TQ significantly eradicated biofilm formed after 6 h and 24 h, as evidenced by bright field microscopy. Thus, the results provide scope on the quicker microwave assisted synthesis, which is considered a greener method and the THQ showed potential antimicrobial and antibiofilm activities against common food borne pathogens.

Olive leaf extract-derived chitosan-metal nanocomposite: Green synthesis and dual antimicrobial-anticancer action

In this study, we developed a novel nanocomposite by synthesizing zinc (ZnNPs), copper (CuNPs), and silver (AgNPs) nanoparticles using olive leaf extract and incorporating them into a chitosan polymer. This approach combines the biocompatibility of chitosan with the antimicrobial and anticancer properties of metal nanoparticles, enhanced by the phytochemical richness of olive leaf extract. The significance of our research lies in its potential to offer a biodegradable and stable alternative to conventional antibiotics and cancer treatments, particularly in combating multidrug-resistant bacteria and various cancer types. Comprehensive characterization through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) confirmed the successful synthesis of the nanocomposites, with an average size of ~22.6 nm. Phytochemical analysis highlighted the antioxidant-rich composition of both the olive leaf extract and the nanoparticles themselves. Functionally, the synthesized nanoparticles exhibited potent antimicrobial activity against multidrug-resistant bacterial strains, outperforming traditional antibiotics by inhibiting key resistance genes (ermC, tetX3-q, blaZ, and Ery-msrA). In anticancer assessments, the nanoparticles showed selective cytotoxicity towards cancer cells in a concentration-dependent manner, with CuNPs and AgNPs showing particularly strong anticancer effects, while demonstrating minimal toxicity towards normal cells. ZnNPs were noted for their low cytotoxicity, highlighting the safety profile of these nanoparticles. Further, the nanoparticles induced apoptosis in cancer cells, as evidenced by the modulation of oncogenes (P21, P53, and BCL2), suggesting their therapeutic potential. The findings of our study underscore the versatile applications of these biogenic nanoparticles in developing safer and more effective antimicrobial and anticancer therapies.

Antimicrobial and anti-inflammatory effects of BenTooth: A natural product blend of burdock root, persimmon leaf extracts, and quercetin on periodontal disease

Periodontal disease represents a condition that exhibits substantial global morbidity, and is characterized by the infection and inflammation of the periodontal tissue effectuated by bacterial pathogens. The present study aimed at evaluating the therapeutic efficacy of BenTooth, an edible natural product mixture comprising burdock root extract, persimmon leaf extract and quercetin, against periodontitis both in vitro and in vivo. BenTooth was examined for antimicrobial properties and its impact on cellular responses related to inflammation and bone resorption. Its effects were also assessed in a rat model of ligature-induced periodontitis. BenTooth demonstrated potent antimicrobial activity against P. gingivalis and S. mutans. In RAW264.7 cells, it notably diminished the expression of inducible nitric oxide synthase and cyclooxygenase-2, as well as reduced interleukin-6 and tumor necrosis factor-α levels triggered by P. gingivalis-derived lipopolysaccharide. Furthermore, BenTooth inhibited osteoclastogenesis mediated by the receptor activator of nuclear factor κB ligand. In the rat model, BenTooth consumption mitigated the ligature-induced expansion in distance between the cementoenamel junction and the alveolar bone crest and bolstered the bone volume fraction. These results present BenTooth as a potential therapeutic candidate for the prevention and remediation of periodontal diseases.

Comparative versatility and diverse biological applications of eco-friendly zinc oxide and cobalt oxide nanoparticles using Punica granatum L. peel extract

A fundamental element of nanotechnology today is the advancement of sustainable, environmentally friendly and economically viable approaches to green synthesis of nanomaterials. In this study, fresh aqueous extract of pomegranate peels was used as reducing and stabilizing agents in a rapid and eco-friendly approach for the synthesis of zinc oxide nanoparticles (ZnO-NPs) and cobalt oxide nanoparticles (Co3O4-NPs). X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission electron microscope (TEM), Energy Dispersive Analysis of X-rays (EDX), and Fourier-transform Infrared Spectroscopy (FT-IR) were used to analyze the biosynthesized ZnO-NPs and Co3O4-NPs. XRD analysis confirmed the crystalline structures of ZnO-NPs and Co3O4-NPs as approximately 33.4 and 11.9nm, respectively. SEM images showed distinct morphologies, while EDX and elemental mapping confirmed compositional integrity. FT-IR validated the characteristic functional groups present in both nanoparticles. TEM analysis provide the average particle size of ZnO-NPs and Co3O4-NPs were observed at 41.25 and 17.19nm, respectively. The zeta potential of green synthesized ZnO-NPs and Co3O4-NPs were found to have a distinct peak at -12.5 and -16.3mV, respectively. Both NPs have shown potent antimicrobial activity against four common pathogens, with increased antimicrobial activity against increasing concentrations of NPs. In vivo studies show a protective role for both ZnO-NPs and Co3O4-NPs against doxorubicin (DOX)-induced toxicity. In addition, Co3O4-NPs were effective against hepatotoxicity, nephrotoxicity, and endocrine disruption in male albino rats. Multi-technique investigation in this study offers a comprehensive understanding and indicates promising biological applications of ZnO-NPs and Co3O4-NPs.

In vitro antimicrobial, anticancer evaluation, and in silico studies of mannopyranoside analogs against bacterial and fungal proteins: Acylation leads to improved antimicrobial activity

Carbohydrate analogs are an important, well-established class of clinically useful medicinal agents that exhibit potent antimicrobial activity. Thus, we explored the various therapeutic potential of methyl α-D-mannopyranoside (MαDM) analogs, including their ability to synthesize and assess their antibacterial, antifungal, and anticancer properties; additionally, molecular docking, molecular dynamics simulation, and ADMET analysis were performed. The structure of the synthesized MαDM analogs was ascertained by spectroscopic techniques and physicochemical and elemental analysis. In vitro antimicrobial activity was assessed and revealed significant inhibitory effects, particularly against gram-negative bacteria along with the prediction of activity spectra for substances (PASS). Concurrently, MαDM analogs showed good results against antifungal pathogens and exhibited promising anticancer effects in vitro, demonstrating dose-dependent cytotoxicity against Ehrlich ascites carcinoma (EAC) cancer cells while sparing normal cells from compound 5, with an IC50 of 4511.65 µg/mL according to the MTT colorimetric assay. A structure–activity relationship (SAR) study revealed that hexose combined with the acyl chains of decanoyl (C-10) and benzenesulfonyl (C6H5SO2-) had synergistic effects on the bacteria and fungi that were examined. Molecular docking was performed against the Escherichia coli (6KZV) and Candida albicans (1EAG) proteins to acquire insights into the molecular interactions underlying the observed biological activities. The docking results were further supported by 100 ns molecular dynamics simulations, which provided a dynamic view of the stability and flexibility of complexes involving MαDM and its targets. In addition, ADMET analysis was used to evaluate the toxicological and pharmacokinetic profiles. Owing to their promising drug-like properties, these MαDM analogs exhibit potential as prospective therapeutic candidates for future development.

Integrative Genomics and Bioactivity-Guided Isolation of Novel Antimicrobial Compounds from Streptomyces sp. KN37 in Agricultural Applications.

Actinomycetes have long been recognized as an important source of antibacterial natural products. In recent years, actinomycetes in extreme environments have become one of the main research directions. Streptomyces sp. KN37 was isolated from the cold region of Kanas in Xinjiang. It demonstrated potent antimicrobial activity, but the primary active compounds remained unclear. Therefore, we aimed to combine genomics with traditional isolation methods to obtain bioactive compounds from the strain KN37. Whole-genome sequencing and KEGG enrichment analysis indicated that KN37 possesses the potential for synthesizing secondary metabolites, and 41 biosynthetic gene clusters were predicted, some of which showed high similarity to known gene clusters responsible for the biosynthesis of antimicrobial antibiotics. The traditional isolation methods and activity-guided fractionation were employed to isolate and purify seven compounds with strong bioactivity from the fermentation broth of the strain KN37. These compounds were identified as 4-(Diethylamino)salicylaldehyde (1), 4-Nitrosodiphenylamine (2), N-(2,4-Dimethylphenyl)formamide (3), 4-Nitrocatechol (4), Methylsuccinic acid (5), Phenyllactic acid (6) and 5,6-Dimethylbenzimidazole (7). Moreover, 4-(Diethylamino)salicylaldehyde exhibited the most potent inhibitory effect against Rhizoctonia solani, with an EC50 value of 14.487 mg/L, while 4-Nitrosodiphenylamine showed great antibacterial activity against Erwinia amylovora, with an EC50 value of 5.715 mg/L. This study successfully isolated several highly active antimicrobial compounds from the metabolites of the strain KN37, which could contribute as scaffolds for subsequent chemical synthesis. On the other hand, the newly predicted antibiotic-like substances have not yet been isolated, but they still hold significant research value. They are instructive in the study of active natural product biosynthetic pathways, activation of silent gene clusters, and engineering bacteria construction.

Chemical composition, antioxidant, antimicrobial and antibiofilm activities of essential oil from the Moroccan endemic Plant, Calendula maroccana (Ball) B. D. Jacks.

Chemical composition, antioxidant, antimicrobial and antibiofilm activities of essential oil from the Moroccan endemic Plant, <i>Calendula maroccana</i> (Ball) B. D. Jacks.

Exploring nonlinear optical properties in a hybrid dihydrogen phosphate system: an experimental and theoretical approach.

The controlled slow evaporation process conducted at room temperature has produced a novel hybridmaterial denoted as (2-hydroxyethyl) trimethylammonium dihydrogen phosphate [2-HDETDHP](C5H14NO+, H2PO4-), synthesized through the solution growth method. X-ray crystallographyanalysis reveals a triclinic structure with a filling rate of P and a Z value of 2. This hybrid materialdisplays noteworthy absorption characteristics in the middle and far ultraviolet regions. UV-visiblespectroscopy further establishes its transparency in the visible and near-visible ultraviolet domains.FT-IR spectroscopy examines various vibration modes, elucidating their relationships with thefunctional groups within the structure. Two- and three-dimensional fingerprint maps, coupled withthree-dimensional crystal structures through Hirshfeld Surface Analysis, unveil the dominance of O•••Hand H•••H interactions in the structure, comprising 49.40% and 50.40%, respectively. Fingerprint plotsderived from the Hirshfeld surface assess the percentages of hydrogen bonding interactions, with80.6% attributed to a fragment patch. The experiment of antimicrobial efficacy of a synthesizedproduct, conducted in triplicate, demonstrated the synthesized product's potential antimicrobial activity. Hirshfeld surfaces are employed to investigate intermolecular hydrogen bonding, specifically withinsingle phosphate groups. The molecular structure of 2-HDETDHP was refined using single-crystal X-ray analysis, while itsoptical characteristics were examined through UV-visible spectroscopy. FT-IR spectroscopy isemployed for the assignment of molecular vibrations of functional groups in the affined structure. Quantum calculations were executed with the GAUSSIAN 09 software package at B3LYP/6-311Glevel of theory, to optimize the molecular geometries. The antimicrobial efficacy of a synthesized product was evaluated using the disc diffusion methodagainst antibiotic-resistant Candida albicans, Candida tropicalis, Aspergillus niger, Staphylococcusaureus, and Escherichia coli. Microorganisms were cultured on nutrient agar, and inhibition zoneswere measured after incubation, with streptomycin and amphotericin as positive controls.

The antimicrobial fibupeptide lugdunin forms water-filled channel structures in lipid membranes

Recently, a novel cyclo-heptapeptide composed of alternating d,l-amino acids and a unique thiazolidine heterocycle, called lugdunin, was discovered, which is produced by the nasal and skin commensal Staphylococcus lugdunensis. Lugdunin displays potent antimicrobial activity against a broad spectrum of Gram-positive bacteria, including challenging-to-treat methicillin-resistant Staphylococcus aureus (MRSA). Lugdunin specifically inhibits target bacteria by dissipating their membrane potential. However, the precise mode of action of this new class of fibupeptides remains largely elusive. Here, we disclose the mechanism by which lugdunin rapidly destabilizes the bacterial membrane potential using an in vitro approach. The peptide strongly partitions into lipid compositions resembling Gram-positive bacterial membranes but less in those harboring the eukaryotic membrane component cholesterol. Upon insertion, lugdunin forms hydrogen-bonded antiparallel β-sheets by the formation of peptide nanotubes, as demonstrated by ATR-FTIR spectroscopy and molecular dynamics simulations. These hydrophilic nanotubes filled with a water wire facilitate not only the translocation of protons but also of monovalent cations as demonstrated by voltage-clamp experiments on black lipid membranes. Collectively, our results provide evidence that the natural fibupeptide lugdunin acts as a peptidic channel that is spontaneously formed by an intricate stacking mechanism, leading to the dissipation of a bacterial cell’s membrane potential.

A Novel Comparative Identification Method of Alkaloid and Flavonoid from Leaves of Spathodea Campanulata

Spathodea campanulata is a medicinal plant that has been used for the treatment and prevention of various diseases. In this study, we present a comparative method for the identification of alkaloids and flavonoids from the leaves of the plant. We employed a combination of extractive screening methods and microscopic examination to identify and differentiate these bioactive compounds. The results obtained from this study provide valuable insights into the phytochemical composition of this medicinal plant and contribute to the understanding of its therapeutic potential. The identified compounds can be further isolated and purified to assess their efficacy and safety profiles. In addition, the identified compounds could be subjected to in vitro and in vivo studies to evaluate their potential antioxidant, antimicrobial, anti-inflammatory, and anticancer activities. In conclusion, this research not only contributes to the knowledge of the pharmacological properties of this plant but also paves the way for further research and development in the field of herbal medicine.

Antimicrobial activity of cell-free supernatant derived from Ligilactobacillus animalis SWLA-1 in a novel ex vivo canine corneal infection model.

Canine bacterial keratitis is a corneal infection that causes various symptoms, including visual impairment, and necessitates eye removal in severe cases. Staphylococcus pseudintermedius is a pathogen that causes significant bacterial keratitis in canine patients. Moreover, multi-drug resistant Staphylococcus pseudintermedius (MDRSP) has been reported in both humans and animals. Regarding treatment failure against multi-drug resistant (MDR) pathogens with classic antibiotics, antimicrobial compounds derived from probiotics have been suggested as an alternative approach. Ligilactobacillus animalis SWLA-1 strain and its cell-free supernatant (CFS) have previously demonstrated potent antimicrobial activity against various MDR pathogenic bacteria. Based on this finding, we evaluated the anti-staphylococcal activity of CFS derived from Ligilactobacillus animalis SWLA-1 against MDRSP in a newly established ex vivo canine corneal infection model using fresh canine corneoscleral rims. Additionally, an in vitro cytotoxicity test using human keratocytes was performed. CFS significantly inhibited the growth of MDRSP in the novel ex vivo model and did not exhibit any significant toxicity against keratocytes in vitro. Based on these results, the antimicrobial compounds in CFS show potential as a novel approach for MDR staphylococcal keratitis treatment.

Enhancing antimicrobial efficacy: 8-Hydroxyquinoline incorporation into metal-organic frameworks with iron ion coupling

The antimicrobial properties of 8-Hydroxyquinoline (8-Hq), a small organic compound known for its metal-chelating capabilities, hold significant promise. However, its limited solubility in water poses a challenge for practical applications. In this study, we address this limitation by augmenting the antimicrobial efficacy of 8-Hq through its integration into the metal-organic framework UiO-66 (named 8-Hq@UiO-66) and coupling it with iron ions (designated as Fe/8-Hq@UiO-66) via an adsorption process. The sorption isotherm and adsorption kinetics were meticulously examined using Langmuir's adsorption model and the pseudo-second-order kinetic model. Material characterization techniques including powder X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption isotherms, ultraviolet–visible spectroscopy, and photoluminescence spectroscopy revealed the coordination of zirconium clusters and iron with the nitrogen and hydroxyl groups of 8-Hq, respectively. Furthermore, our investigation into metal ion adsorption demonstrated that the 8-Hq@UiO-66 composite displayed a notable selectivity for iron ions over other metal ions in aqueous media. Under optimized conditions, the adsorption capacity for iron ions ranged from approximately 34–46 mg g−1. Importantly, the Fe/8-Hq@UiO-66 composite exhibited potent antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. These findings underscore the potential of incorporating 8-Hq into porous metal-organic frameworks and coupling it with iron ions to enhance its antimicrobial efficacy.