Search Results (17,382)

As we previously demonstrated that tranexamic acid (TXA), an antifibrinolytic, showed an antibacterial effect alone and in combination with vancomycin and gentamicin, we now wanted to analyze its own efficacy using new, different fluorescent staining reagents that target different components of the biofilm matrix and compare which one quantifies biofilm reduction better. A 10⁸ cfu/mL suspension of the Staphylococcus aureus (ATCC29213) strain was placed into the wells of a 24-multiwell plate covered with glass slides coated with 10% poly-L-lysine under agitation for 24 h at 37 °C. After 3 washes with PBS, wells were treated with either TXA 10 mg/mL or sterile water and incubated for 24 h at 37 °C. After three washes with PBS, the density area of the following biofilm components was calculated using confocal laser scanning microscopy: extracellular proteins (Sypro Ruby), α-extracellular polysaccharides (ConA-Alexa fluor 633), α or β-extracellular polysaccharides (GS-II-Alexa fluor 488), bacterial DNA (PI), and eDNA (TOTO^®-1). We observed a statistically significant reduction in the occupied area by all components of the S. aureus biofilm (p < 0.001) after TXA 10 mg/mL treatment, compared to the positive control. All biofilm components’ reduction percentages reached ≥90.0%. We demonstrated that TXA reduced both bacteria and extracellular matrix components of S. aureus biofilm by using five different stain reagents, with all being equally valid for quantification. Full article

The search for new antimicrobial agents is one of the major challenges in contemporary medicinal chemistry due to the global issue of increasing drug resistance. In our efforts to identify chemical structures with antibiotic activity that differ from commonly used antibiotics, we focused our research on (thio)semicarbazides and hydrazones. Guided by literature reports, we designed and synthesized a series of novel semicarbazides, thiosemicarbazides, and hydrazones based on the structure of 4-(morpholino-4-yl)-3-nitrobenzohydrazide. The obtained derivatives were subsequently evaluated in in vitro assays for their activity against reference strains of Gram-positive and Gram-negative bacteria. Among the studied groups of compounds, the semicarbazide derivatives exhibited the highest activity. The most active compound identified in the study was a semicarbazide containing a 4-bromophenyl moiety. This compound showed antibacterial potential against Enterococcus faecalis, with a MIC value of 3.91 µg/mL. Among the thiosemicarbazides, the most active compound contained a 4-trifluoromethylphenyl group, with MIC values against Gram-positive bacterial strains (excluding Staphylococcus aureus) ranging from 31.25 to 62.5 µg/mL. None of the tested hydrazones exhibited antimicrobial activity against the examined bacteria. Additionally, the structures of the new compounds were confirmed by single-crystal X-ray analysis, which enabled the investigation of their properties using advanced quantum chemical calculations. Full article

This study explores the sustainable extraction and application of natural dyes from figs (Ficus carica) and Eucalyptus leaves using an aqueous alkaline medium. The dyeing process was optimized for cotton fabric using the exhaust-dyeing method. Fabrics dyed with Ficus carica extract and its blend with Eucalyptus exhibited enhanced color strength, excellent crocking fastness (rated 4–5), and good washing fastness (rated 3–4 on the gray scale). The use of Aloe barbadensis Miller as a bio-mordant significantly improved dye fixation, resulting in deeper, earthy shades, such as green, yellow–green, and yellowish brown. The highest K/S value (5.85) was recorded in samples treated with a mordant, sodium chloride (NaCl), and the combined dye extracts, indicating a synergistic effect among the components. Mosquito repellency tests revealed that treated fabrics exhibited up to 70% repellency, compared to just 20% in undyed samples. Antibacterial testing against E. coli showed that dyed fabrics achieved over 80% bacterial reduction after 24 h, indicating promising antimicrobial functionality. Air permeability slightly decreased post-dyeing due to the potential shrinkage in cotton fabrics. Furthermore, adsorption studies showed a removal efficiency of 57% for Ficus carica dye on graphene oxide (GO) under ultrasonication. These findings confirm the potential of GO as an effective adsorbent material for treating wastewater from natural textile dyes. Overall, the study highlights the environmental safety, functional performance, and multifunctional advantages of plant-based dyeing systems in sustainable textile applications. Full article

Antimicrobial materials are gaining significant interest as awareness of pathogens spread through contact becomes increasingly prevalent. While various compounds with antibacterial properties have been explored as active ingredients in such materials, many are prone to leaching, leading to undesirable risks to the environment and to human health. Herein, we develop and test a multilayered plastic film filled with silver nanoparticles, long known to be potent antibacterial agents, supported in a silica matrix. Cross-linked methacrylate layers on both sides of these nanostructures prevent leaching even after several uses, making the material essentially benign. Furthermore, we derive silica from rice husk, an abundant and affordable agricultural waste product. Our findings demonstrate that initial irradiation of the material with UVA light facilitates the photothermal migration of nanoparticles towards the material’s surface, thereby significantly enhancing its antimicrobial properties. Remarkably, after just 5 min of visible light irradiation, the material exhibits over 99.999% inhibition of bacterial growth. This environmentally friendly plastic composite harnesses visible light to actively combat bacteria, providing an exciting proof-of-concept for future applications in antimicrobial coatings. Full article

The objective of this study is to evaluate, for the first time, the chemical composition and the antioxidant, enzyme inhibitory, photoprotective and antibacterial properties of the Tamarix boveana essential oil (EO) as well as its organic extracts. The analysis of the EO obtained from the aerial parts of T. boveana was carried out employing the technique of gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC-MS). Forty-four constituents were identified, constituting 91.18% of the oil, with the major compounds being γ-cadinene (9.41%), β-caryophyllene (6.71%), limonene (6.5%), p-cymene (6.16%), copaene (4.37%), terpinen-4-ol (4.23%), δ-cadinene (4.21%) and γ-terpinene (4.11%). The antioxidant activity of T. boveana essential oil and organic extracts (hydroalcoholic, CHCl₃, AcOEt, n-BuOH) was evaluated by different tests, including DPPH, ABTS, phenanthroline, SNP and ferric reducing power. The findings indicated that T. boveana essential oil possesses moderate antioxidant capacity, with IC₅₀ values of 223.59 ± 1.01 μg/mL according to the DPPH test. The extracts and essential oil also demonstrated notable inhibitory impacts against α-amylase and butyrylcholinesterase. Antimicrobial activity was determined regarding four bacterial strains, determining the minimum inhibitory concentrations (MICs) and bactericidal concentrations (MBCs). The geometry and electronic properties of the main EO compounds were determined using density functional theory (DFT) calculations. Furthermore, docking studies were conducted to investigate the interaction and binding affinity of these molecules with the active sites of BuChE and α-amylase enzymes. The results highlight the value of Tamarix boveana as a medicinal plant and indicate its effectiveness as an important source of bioactive compounds for many uses. Full article

Digestive pathologies are commonly encountered in both human and veterinary medicine, frequently requiring antibiotic intervention. However, their extensive use has contributed to the global increase in antimicrobial resistance, posing a major public health challenge. With the emergence of multidrug-resistant bacteria, alternative antimicrobial strategies are urgently needed. This study assessed the total polyphenolic content and in vitro antimicrobial activity of ethanolic extracts from Origanum majorana, Salvia officinalis, and Ribes nigrum fruits against six digestive bacterial pathogens: Escherichia coli, Salmonella enteritidis, Enterobacter cloacae, Yersinia enterocolitica, Listeria monocytogenes, and Enterococcus faecalis. Antimicrobial activity was evaluated using agar well diffusion and minimum inhibitory concentration (MIC) assays. The total polyphenolic content of the extracts was 8509.457 μg/g for Salvia officinalis, 8140.996 μg/g for Origanum majorana, and 5776.616 μg/g for Ribes nigrum. R. nigrum showed the strongest antimicrobial effect (MIC 0.002 μg/μL; MBC 0.001 μg/μL) against Y. enterocolitica. S. officinalis had the highest efficacy against E. faecalis, while O. majorana was effective against both Y. enterocolitica and E. faecalis. All extracts showed bactericidal activity with MIC index values between 0.5 and 4. These findings suggest that these polyphenol-rich plant extracts may serve as promising natural antimicrobials or as adjuvants to conventional antibiotics. Full article

Antimicrobial peptides (AMPs) are increasingly emerging as alternatives to conventional antibiotics. This study compared the antibacterial activity of two decapeptides, KSL and KSL-W, and a 23-residue peptide, Dadapin-1, against bacterial species that colonize orthopedic implants, with the aim of identifying the most effective peptide for future AMP-based anti-infective orthopedic biomaterials. Staphylococcus aureus ATCC 25923 was the reference strain. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm inhibitory concentration (MBIC) of the AMPs were determined in both undiluted and diluted Mueller–Hinton Broth II (MHB II) to gain a simplified perspective on the potential interference of bioenvironments. The MBICs of the AMPs were close to their MICs. In diluted broth, a concentration of 3.91 μg/mL of KSL or KSL-W was bactericidal against staphylococci and prevented biofilm formation. An eight-fold higher concentration of Dadapin-1 was required to achieve bactericidal activity. Undiluted MHB II significantly hindered the antibacterial activity of KSL and Dadapin-1, while KSL-W was notably less affected. The values of LoA, a newly developed indicator of loss of activity, confirmed these findings. Bacterial species and strain influenced LoA. Furthermore, KSL-W exhibited a protective effect on osteoblasts co-cultured with S. aureus ATCC 25923. Overall, KSL-W emerged as the most promising candidate for AMP-based anti-infective orthopedic biomaterials. Full article

Carboxymethyl cellulose (CMC) films, derived from sugarcane bagasse agricultural waste (SCB) incorporated with Betalains-nitrogen-doped carbon dots (Betalains-N–CQDs), derived from beet root waste (BR), offer a sustainable, smart and naked-eye sensor for strawberry packaging due to their excellent fluorescent and shape memory properties. These CMC-Betalains-N–CQDs aim to enhance strawberry preservation and safety by enabling visual detection of common food contaminants such as bacteria, fungi and Pb(II). Crucially, the CMC-Betalains-N–CQD film also exhibits excellent shape memory properties, capable of fixing various shapes under alkaline conditions and recovering its original form in acidic environments, thereby offering enhanced physical protection for delicate produce like strawberries. Optical studies reveal the Betalains-N–CQDs’ pH-responsive fluorescence, with distinct emission patterns observed across various pH levels, highlighting their potential for sensing applications. Scanning Electron Microscopy (SEM) confirms the successful incorporation of Betalains-N–CQDs into the CMC matrix, revealing larger pores in the composite film that facilitate better interaction with analytes such as bacteria. Crucially, the CMC-Betalains-N–CQD film demonstrates significant antibacterial activity against common foodborne pathogens like Escherichia coli, Staphylococcus aureus, and Candida albicans, as evidenced by inhibition zones and supported by molecular docking simulations showing strong binding interactions with bacterial proteins. Furthermore, the film functions as a fluorescent sensor, exhibiting distinct color changes upon contact with different microorganisms and Pb(II) heavy metals, enabling rapid, naked-eye detection. The film also acts as a pH sensor, displaying color shifts (brown in alkaline, yellow in acidic) due to the betalains, useful for monitoring food spoilage. This research presents a promising, sustainable, and multifunctional intelligent packaging solution for enhanced food safety and extended shelf life. Full article

This study aimed to identify a probiotic bacterium with antagonistic activity against the foodborne pathogen Staphylococcus aureus (S. aureus) and investigate the mechanism of its antibacterial components. Growth kinetics were analyzed to assess bacterial proliferation. Acid and bile salt tolerance are vital indicators for evaluating probiotic survival in the gastrointestinal tract. The results indicated that Companilactobacillus farciminis (C. farciminis) YLR-1 not only had high tolerance to salt conditions (0.03%, 0.3%, and 0.5%) but also has a high survival rate at pH 3–4. The bacteriocin-like inhibitory substance (BLIS) isolated from C. farciminis YLR-1 was dialyzed using a membrane with a molecular weight cut-off (MWCO) of 500 Da, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The results indicate that the BLIS produced by C. farciminis YLR-1 is a small-molecule peptide. BLIS displayed pH tolerance within acidic and neutral environments (4–8) and exhibited thermostability. When treated with proteinase K, the antibacterial action of BLIS was found to be inactivated. Membrane disruption mechanisms were examined using fluorescence imaging and scanning electron microscopy (SEM). SEM and fluorescence imaging revealed that BLIS-induced membrane damage in S. aureus ATCC 25923 causes cytoplasmic leakage and cell death. Full article

The genus Bauhinia has over 350 species distributed on different continents of the world. The vast majority of the species in this genus possess interesting biological activities. Also, they are good sources of flavonoids, which are known to elicit excellent pharmacological properties and are well-positioned as potential drug candidates. A literature search was performed with proper consideration of articles published and indexed in PubMed, Scopus, Springer Link, Google Scholar, ScienceDirect, SciFinder, and Medline databases between 1980 and 2023. A total of 164 flavonoids isolated from the genus Bauhinia were reviewed, and biological activities including antidiabetic, anti-cancer, antibacterial, cytotoxicity, antidiarrheal, antioxidant, anti-inflammatory, and anti-cataract were all reported. This study gave a comprehensive review of these flavonoids through detailed classification, structural diversity, and pharmacological activities. Full article

Wound healing is a physiological process including haemostasis, inflammation, proliferation, and remodelling. Acute wounds typically follow a predictable healing process, whereas chronic wounds cause prolonged inflammation and infection, failing to progress through typical healing phases and presenting significant clinical challenges. A combination of wound care techniques and therapeutic agents is required to manage chronic wounds effectively. Curcumin is a bioactive compound derived from Curcuma longa and has gained attention for its potent antioxidant, anti-inflammatory, and antibacterial properties. The first part of this review aims to provide a comprehensive overview of the physiology of wound healing, focusing on the pathophysiology and management of acute and chronic wounds, followed by the biological activity of curcumin in wound healing, emphasising its impact on promoting tissue repair. Finally, this review explores curcumin-loaded dressings, such as hydrogels, nanofibrous membranes, polymeric micelles, and films, offering controlled drug release and targeted curcumin delivery to enhance wound healing. Full article

Background and Clinical Significance: Anaerococcus tetradius (A. tetradius) and Gardnerella vaginalis (G. vaginalis) are rare etiological factors for postpartum endometritis and are typically associated with bacterial vaginosis. However, in some cases, G. vaginalis and A. tetradius can cause serious postpartum endometritis with complications such as sepsis. Case Presentation: 26-year-old pregnant woman expecting monochorionic diamniotic twins presented to the hospital at 35 weeks and 3 days of gestation and two male infants were delivered via the Cesarean section. On the fifth day after delivery, the patient began to complain of intense abdominal pain, a fever of 37.9 °C, and overall weakness. Blood tests revealed neutrophilic leukocytosis, increased C-reactive protein (CRP) of 225.4 mg/L. Upon examination, abdominal distension, tenderness on palpation, and positive symptoms of peritoneal irritation were present and the site of the abdominal incision was inflamed with flowing foul-smelling greenish pus. Ultrasound examination revealed free fluid collection in the peritoneal cavity, under the liver, and around the uterus. Later, the condition of the patient worsened with progressing hypotension and respiratory distress. As a result, suppurative peritonitis and sepsis was suspected and the patient underwent urgent total hysterectomy without oophorectomy. Acute endometritis, focal myometritis, and chronic cervicitis were concluded from histopathological examination of the removed uterus. Microbiological tests showed the most abundant growth of A. tetradius in the wound cultures and great abundance of G. vaginalis in the abdominal cavity cultures. After trying three different treatment schemes and difficulties with determining the antibiotic sensitivity tests for pathogens, the antibacterial therapy was escalated to Meropenem, which was found to be effective, and the patient was discharged home. Conclusions: This case report highlights the severity of complications of postpartum endometritis that can be caused by rare pathogens (such as G. vaginalis and A. tetradius), and strategies for how to manage it. The clinical presentation of a patient should be monitored closely for several days after Cesarean section and if endometritis is suspected, microbiological cultures are necessary to determine the cause of infection and implement an appropriate treatment. Full article

Background: Occlusion of plastic biliary stents is a common complication in biliary drainage, often requiring exchange procedures every 2–4 months due to microbial colonization and sludge formation. This study aimed to evaluate diamond-like carbon (DLC) coatings, with and without silver nanoparticle additives, for preventing stent occlusion. Methods: Polyethylene (PE) stents were coated with DLC using PlasmaImpax for DLC-1 and pulsed laser deposition for DLC-2. Silver ions (Ag) were incorporated into the DLC-2 coatings. To simulate in vivo conditions, a co-culture of Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Candida albicans (C. albicans) was used for microbial colonization. Standardized human bile simulated physiological conditions. Adhesion tests, weight measurements, and scanning electron microscopy (SEM) quantified bacterial adherence to stents. Results: DLC-1 coatings demonstrated higher bacterial growth than uncoated PE stents with E. faecalis (adhesion assay difference: 0.6 log [p = 0.19] and 0.1 log [p = 0.75] in rounds 1 and 2, respectively). In the bile incubation model, DLC-1 did not significantly reduce bacterial counts at 5 days (0.4 log [p = 0.06]) or 14 days (0.2 log [p = 0.44]). DLC-2 showed no significant reduction either. DLC-2-Ag significantly reduced bacterial adhesion (5 days: −0.3 log [p = 0.00]; 14 days: −0.4 log [p = 0.16]) and exhibited inhibition zones against E. faecalis (2.3 mm), E. coli (2.1 mm), and C. albicans (0.6 mm). SEM revealed cracks and flaking in the coating. Conclusions: DLC coatings alone did not prevent microbial adhesion. Tendencies of anti-adhesive properties were seen with Ag-doped DLC coatings, which were attributed to the antibacterial effects of Ag. Optimization of the DLC-coating process is needed to improve stent performance. Future studies with larger samples sizes are needed to confirm the observed trends. Full article

Chronic wounds pose a great challenge due to their slow healing and susceptibility to infections, hence the need for innovative alternatives to conventional antibiotics, as increasing bacterial resistance limits the efficacy of current treatments. This paper addresses the development of novel electrospun membranes based on polyvinyl alcohol (PVA) and sodium alginate, incorporating therapeutic ZnO and bioglass (54SiO₂:40CaO:6P₂O₅) nanoparticles. While nanocomposites presented smaller fiber diameters than pure polymers, ternary nanocomposites displayed higher values, e.g., in porous areas, values were in the ca. 80 - 240 nm range and 0.06 - 0.60 mm², respectively. The Young's modulus of the PVA/SA membrane, initially 15.9 ± 2.0 MPa, decreased by 65% with 10 wt.% ZnO NPs, whereas 10 wt.% BG NPs increased it by 100%. The membranes demonstrated efficacy against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) isolated from a human wound secretion, as well as two ATCC strains: Staphylococcus aureus and Staphylococcus epidermidis. A cell viability assay conducted with HaCaT cells demonstrated nearly complete survival following 72 h of membrane exposure. Their combined Gram-positive antibacterial activity and cytocompatibility support their potential application as biofunctional dressings for the management of chronic and hospital-acquired topical infections, while also contributing to the global effort to combat antibiotic resistance. Full article

The increasing prevalence of antibiotic-resistant bacteria has intensified the need for innovative antibacterial surfaces, particularly in biomedical applications. Traditional approaches often rely on chemical agents alone, which may lead to diminishing efficacy over time. To address this, we investigated the development of a novel antibacterial surface by combining the inherent antimicrobial properties of copper with an engineered surface topography on a biopolymer matrix. A copper–poly-L-lactic acid (Cu-PLLA) composite system was fabricated using sputtering deposition followed by controlled thermal treatment to induce wrinkle-like micro- and nanostructures on the surface. The surface morphology was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), confirming the formation of hierarchical wrinkle patterns. The chemical composition and distribution of copper were analyzed via energy-dispersive X-ray spectroscopy (EDS). Antibacterial performance was assessed against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using standard colony count reduction assays. The Cu-PLLA wrinkled surfaces demonstrated significantly enhanced bactericidal activity compared with flat PLLA and copper-free controls, a finding attributed to a synergistic effect of mechanical membrane disruption and copper-mediated chemical toxicity. These findings suggest that biopolymer–metal hybrid surfaces with engineered topography offer a promising strategy for developing next-generation antibacterial materials suitable for biomedical and clinical use. Full article