Search Results (6,085)

Valeriana microphylla is a medicinal species traditionally used in the Andean region. The study aimed to evaluate the bioactive compounds and the antioxidant, antimicrobial, haemolytic, and nematode locomotion-disrupting l activities in the flowers and leaves of V. microphylla. Minerals were quantified by atomic absorption spectrometry, whereas bioactive compounds were analysed by liquid chromatography. Antioxidant, antimicrobial and biological activities were determined by microplate spectrophotometry. Antimicrobial activity was tested against ATCC and multidrug-resistant microorganisms. Haemolytic activity was assessed by haemolysis of sheep erythrocytes, and nematode locomotion-disrupting activity by analysis of the locomotor behaviour of Caenorhabditis elegans. Potassium was the predominant mineral in leaves (2372.1 mg/100 g DW). In contrast, flowers contained the highest concentrations of citric acid (567.0 mg/100 g DW), total carotenoids (58.9 mg/100 g DW), and total phenolics (24,788.1 mg/100 g DW). Both extracts inhibited the growth of several ATCC bacterial strains, showing the lowest inhibitory concentrations against Staphylococcus epidermidis, Edwardsiella tarda and Listeria monocytogenes, but showed no activity against multidrug-resistant bacteria or against Candida species. Furthermore, both extracts exhibited haemolysis rates of less than 1.3% and affected the locomotion of C. elegans by eliminating the frequency of body bends and reducing locomotion speed. These findings provide an initial phytochemical and in vitro biological characterisation of V. microphylla and support further investigation of its bioactive constituents. Full article

Background/Objectives: Renal ischemia–reperfusion injury (IRI) and infection-associated renal damage are characterized by persistent inflammation, oxidative stress, microvascular dysfunction, and impaired tissue regeneration, creating a hostile microenvironment that limits effective repair. We developed an injectable, photocrosslinkable methacrylated chitosan (CSMA) hydrogel for the localized co-delivery of cerium oxide nanoparticles (CeO₂NPs) and vascular endothelial growth factor (VEGF), aiming to integrate redox modulation, antibacterial activity, and regenerative support. Methods: Gelation, microstructure, rheology, degradation, and CeO2NP/VEGF were characterized. Tubular epithelial and fibroblast migration and endothelial network formation, angiogenic gene expression, and antibacterial activity against Staphylococcus aureus and Escherichia coli were evaluated in vitro. Theraputic performance was assessed by renal surface application in a rat renal IRI model and catheter-mediated interavsical administration in an ascending urinary tract infection model. Systematic biocompatibility was evaluated separately in a 14-day subcutaneous implantation study. Renal response were further investigated using transcriptomic and targeted molecular analyses. Results: The CSMA/VEGF/CeO₂NPs hydrogel exhibited rapid in situ gelation, interconnected porous architecture, stable viscoelasticity, gradual degradation, and sustained release of both CeO₂NPs and VEGF. The formulation enhanced tubular epithelial and fibroblast migration, promoted endothelial network formation and angiogenic gene expression and effectively inhibited both S. aureus and E. coli. In a surgically controlled rat renal IRI model, direct renal-surface application of the hydrogel reduced tubular injury, inflammatory infiltration, and fibrotic remodeling. In a separate ascending urinary tract infection model, catheter-based intravesical administration reduced the ascending renal bacterial burden and infection-associated inflammatory injury. No detectable adverse systemic effects observed under the tested conditions over the 14-day observation period in the subcutaneous implantation. Transcriptomic analyses further revealed that CSMA/VEGF/CeO₂NPs treatment was associated with marked remodeling of the renal injury microenvironment, characterized by suppression of antigen presentation and immune activation pathways, alongside restoration of metabolic programs associated with amino acid, lipid, and purine metabolism. These molecular changes were accompanied by downregulation of CIITA/CD74/MHC-II signaling, recovery of metabolic regulators AGXT and ACOX1, modulation of Hippo/YAP- and ECM-associated pathways, and preservation of renal structural markers including nephrin and WT1. Conclusions: The localized CSMA-mediated co-delivery of CSMA/VEGF/CeO₂NPs hydrogel promotes renal repair through resolution of maladaptive immune activation, metabolic reprogramming, angiogenic enhancement, and preservation of renal structural integrity, providing a promising biomaterial strategy for the treatment of ischemic and infection-associated renal injuries. Full article

Amorphophallus spp., valued as both crops and medicinal plants, are highly susceptible to soft rot disease, causing substantial yield and economic losses during cultivation and storage. Calcium nanoparticle (CaNP) fertilizer not only has the potential to enhance crop yields but also plays a crucial role in the control of crop pests and diseases. However, its application in the control of soft rot disease in konjac has not yet been investigated. In this study, the antibacterial efficacy of CaNP fertilizer against the typical soft rot pathogen P. aroidearum MY11 in Amorphophallus konjac (A. konjac) was investigated. It was found that CaNP fertilizer significantly inhibited the growth, motility ability and the activity of cell wall-degrading exoenzymes of P. aroidearum MY11. Transmission electron microscopy revealed that the morphology of bacterial cells treated with CaNPs did not change significantly, but significant particle deposition was observed within the cells. Furthermore, CaNPs pretreatment could reduce the reactive oxygen species (ROS) content, activate the antioxidant enzyme system, and enhance the photosynthetic capacity of A. konjac plants. qRT-PCR analysis revealed that CaNPs pretreatment might enhance the resistance of A. konjac plants to the soft rot pathogen MY11 by activating the jasmonic acid (JA), salicylic acid (SA) signaling pathway and the cell wall stress response pathway. This research provides a new candidate for nanopesticides that can be used to control the bacterial soft rot disease of konjac. Full article

The modulation of ZnO physicochemical properties through Mn doping represents a promising strategy for the development of multifunctional nanomaterials with enhanced biological performance. In this study, we investigate how the nominal Mn concentration influences both the physicochemical properties and antibacterial, antibiofilm, and anti-virulence activities of ZnO nanoparticles (NPs). Mn-doped ZnO nanoparticles containing nominal Mn from 2.5 to 10 mol% were synthesized through a simple wet-chemical approach and characterized by UV–Vis, Raman, TEM, EDX, and EELS analyses. The resulting ZnO-based NPs showed average dimensions of 3.7–4.8 nm, while increasing Mn incorporation produced measurable changes in optical response and morphology of nanoparticles. Antibacterial activity was evaluated against Gram-positive and Gram-negative bacterial models by assessing planktonic growth inhibition, biofilm formation, and pyocyanin production. The sample with the highest Mn amount (Mn₁₀-ZnO) markedly enhanced antibacterial performance by reducing MIC₉₀ from 150 to 37.5 μg/mL against Staphylococcus aureus and from 300 to 75 μg/mL for Pseudomonas aeruginosa. Mn doping also enhanced biofilm inhibition and produced a progressive reduction in pyocyanin synthesis. These results establish a concentration-dependent relationship between Mn concentration, nanoparticle properties, and antibacterial performance, highlighting the potential of Mn-doped ZnO nanoparticles for the development of anti-infective biomaterials, including antimicrobial coatings for implantable medical devices. Full article

Endophytic bacteria associated with medicinal plants represent a potential source of microorganisms with useful enzymatic and antagonistic properties. In this study, 14 bacterial isolates were recovered from the leaves, roots, flowers, and petioles of Inula helenium and screened for morphological, biochemical, and hydrolytic characteristics. Isolate IH-B3, which showed the most pronounced starch- and casein-hydrolysis zones during preliminary screening, was selected for further characterization. MALDI-TOF mass spectrometry assigned the isolate to Bacillus subtilis with an identification score of 2.26, and the strain was designated B. subtilis UzMU25. Its 1444 bp 16S rRNA gene sequence was deposited in GenBank under accession number PZ593820. The strain was catalase- and lecithinase-positive but gelatinase- and hemolysis-negative, and it grew at pH 6.5 and in the presence of horse bile under the qualitative assay conditions used. Hydrolysis-zone diameters ranged from 46 to 52 mm for amylase, 34 to 42 mm for protease, and 10 to 16 mm for lipase activity. In direct antagonism assays, UzMU25 inhibited all six bacterial and fungal test organisms, producing inhibition zones of 26–36 mm. Biofilm biomass varied with incubation time and reached its highest corrected OD₅₉₀ value at 12 h (0.780 ± 0.025). Antibiotic-disc testing showed a 10 mm inhibition zone for vancomycin, indicating reduced susceptibility under the applied conditions and requiring further investigation of its genetic basis and potential transferability. No mortality was observed during the preliminary acute oral study following administration of the tested preparation at doses up to 10,000 mg kg⁻¹, and no visible dermal or conjunctival irritation was detected. Overall, UzMU25 exhibited preliminary enzymatic, antagonistic, and biofilm-forming characteristics of biotechnological interest. However, whole-genome antimicrobial-resistance screening and more comprehensive phenotypic and toxicological evaluations are required before the strain can be recommended for probiotic or other practical applications. Full article

Background: Motor and intellectual disabilities (MIDs) belong to a restricted and vulnerable social group with health restrictions for maintaining and preserving adequate oral health. Silver nanoparticles (AgNPs) have appeared as an encouraging therapy due to their excellent antimicrobial effects; however, scientific information on the antimicrobial effectiveness of AgNPs against bacteria in patients with MIDs remains limited. This study aimed to evaluate the antimicrobial substantivity of AgNPs in oral bacteria from patients with and without MIDs. Methods: Fifty-four oral biofilm samples were obtained from 26 participants with MIDs and 28 participants without MIDs. The microbial inhibition activity and the antimicrobial substantivity of AgNPs were determined. The antibiofilm activity of the AgNPs was explored using scanning electron microscopy (SEM). Results: The AgNPs displayed uniform size distributions (9.8 ± 1.7 nm) and electrical charges in surface particles that limit particle clustering (−39.8 ± 3.3 mV). The AgNPs were more effective than chlorhexidine (CHX) in eliminating bacteria from oral biofilms derived from both MID and non-MID patients (p < 0.05); therefore, the antimicrobial substantivity of the AgNPs was statistically better than deionized water but lower than CHX at specific exposure times (p < 0.05). The antimicrobial effectiveness of AgNPs at even low concentrations was associated with the type of oral biofilm, the type of antimicrobial solution, and, in some cases, gender. SEM images indicate a clear alteration in oral biofilm structure when AgNPs were applied. Conclusions: AgNPs exhibited significant potential to limit oral bacterial proliferation from microbial biofilms while contributing to the maintenance of oral condition in individuals with MIDs. Full article

Staphylococcus aureus (S. aureus) is a prominent foodborne pathogen that poses a continuous threat to global public health and food safety due to its possession of a variety of toxins and its multidrug resistance. Medium-chain fatty acids (MCFAs), notably lauric acid (LA), exhibit strong antimicrobial properties, but their application is heavily constrained by poor water solubility. In this study, optimized LA emulsions stabilized by chitosan (CS) and polyvinyl alcohol (PVA) were evaluated for their antibacterial activity and detailed mode of action against S. aureus ATCC 6538. The antibacterial activities were evaluated by the maximum inhibition zone, with the 20 CS-PVA/DLTA-LA formulation exhibiting stable dispersion and potent antibacterial activity at 1%. The underlying antibacterial mechanisms against S. aureus were specifically focused on cell membranes and peptidoglycan. Therein, the binding of emulsion droplets to the anionic bacterial surface was driven by electrostatic attraction. Membrane degradation was also observed with membrane dysfunctions involving membrane depolarization, increased permeability, and fluidity reduction triggered by their subsequent insertion into the lipid bilayer, which may cause cell dysmetabolism, disintegration, and eventual cell death. Overall, these findings substantiate that LA emulsions disrupt S. aureus by operating potentially multi-targeted effects involving cell membrane disruption and peptidoglycan interference, offering a promising alternative approach warranting further investigation for foodborne pathogen control. Full article

This study evaluated the antimicrobial activity of meads produced by mixed fermentation of Saccharomyces cerevisiae var. boulardii and a kombucha culture, using eucalyptus- and rosemary-monofloral honeys. Antimicrobial activity was investigated in vitro against pathogenic bacteria (Escherichia coli, Salmonella enterica, Listeria innocua, Staphylococcus aureus, and Bacillus cereus) and spoilage yeasts, over 28 days of storage. All tested matrices were autoclaved at 121 °C for 15 min before antimicrobial evaluation to eliminate viable fermentation microorganisms. Additionally, assays were conducted in simulated food systems at different substrate concentrations, characterizing organic acids, reducing sugars, and volatile compounds. Unfermented musts allowed survival of L. innocua and B. cereus, with rosemary honey showing stronger antimicrobial effects than eucalyptus. Kombucha exerted strong initial inhibition, possibly associated with its high organic acid concentrations, but did not completely inhibit the growth of Gram-positive bacteria. No pathogenic bacterial growth was detected in the fermented mead matrices, possibly due to reduced fermentable sugars, ethanol, organic acids, and other fermentation metabolites. Spoilage yeasts showed high tolerance to acid and osmotic stress, and efficacy decreased in substrate-rich systems. Importantly, the antimicrobial activity reported here refers specifically to autoclaved fermented matrices and does not necessarily apply to untreated fermented beverages. Full article

Pelargonium graveolens L’Hér. is a widely distributed aromatic plant that has been utilized in traditional medicine for an extended period. It is currently experiencing a surge in popularity in modern phytotherapy. The ethnopharmacological uses of this species include treatment of respiratory tract infections, digestive disorders, and analgesia. The plant’s multifaceted biological activity is attributed to the presence of monoterpenes, such as citronellol and geraniol, as well as non-volatile polyphenolic fractions and organic acids. Research has demonstrated the efficacy of PGEO (P. graveolens essential oil) in mitigating inflammation, a phenomenon attributable to the suppression of NF-κB and MAPK signaling pathways, as well as the inhibition of inflammatory mediators such as histamine, prostaglandins (PGs), and nitric oxide (NO). Furthermore, a broad spectrum of antimicrobial activity has been demonstrated against pathogens such as MRSA and Mycobacterium tuberculosis, whilst myricetin derivatives have been shown to enable the effective eradication of bacterial biofilms. It is also noteworthy that the oil’s components can reduce ACE2 receptor expression, indicating their potential to inhibit SARS-CoV-2 infection. Active compounds, such as geraniol, have been shown to modulate metabolic processes through interaction with LXR and FXR nuclear receptors. In addition, these compounds have been observed to exhibit spasmolytic effects within the gastrointestinal tract by blocking calcium channels. The influence on the HPA axis and the GABAergic system provides a scientific rationale for the plant’s traditional use in reducing stress and anxiety. Nevertheless, variations in chemical composition, determined by geographical origin, and an insufficient number of rigorous clinical data hinder the full medical implementation of this plant. It is imperative that further standardization of extracts and their verification in clinical trials is undertaken. Full article

Environmental concerns regarding the ecotoxicological effects of antifouling biocides have led to the development of products targeting biofilm-forming bacteria. However, the potential for sublethal biocide exposure to promote bacterial adaptation and increase the risk of resistance development poses a potential threat to marine ecosystems and human health, yet it remains insufficiently understood. Although this study focuses on conventional antifouling biocides, the findings are intended to inform the future development and evaluation of both conventional and environmentally friendly antifouling technologies by highlighting the importance of assessing resistance induction at sublethal concentrations. In this study, the effects of three representative antifouling biocides on marine bacterial growth and bacterial adhesion were investigated. Sea-Nine 211 (DCOIT), copper sulphate (CuSO₄), and tributyltin oxide (TBTO; included as a historical reference compound due to its environmental persistence) were tested at four concentrations (0.01, 0.1, 1.0, and 10 µg/mL) against six marine biofilm-forming bacteria: Vibrio proteolyticus, V. aestuarianus, V. harveyi, V. natriegens, Shewanella putrefaciens and Pseudoalteromonas elyakovii. The results showed that Sea-Nine 211 exhibited a strong antibacterial effect at 10 µg/mL against all tested species except V. harveyi, whereas at the lowest concentration it promoted bacterial adhesion in V. proteolyticus. In contrast, TBTO and CuSO₄ showed limited antibacterial activity and increased microbial adhesion at the three lowest concentrations tested. These findings demonstrate that antifouling biocides can induce distinct responses depending on the concentration, ranging from growth inhibition to enhanced bacterial adhesion. Given that reducing biocide release has been proposed as a strategy to mitigate environmental impacts, our results highlight two potential challenges: (i) reduced antifouling efficacy at sublethal concentrations and (ii) an increased risk of bacterial adaptation associated with enhanced adhesion. To support future monitoring and resistance risk assessment, we propose a conceptual Resistance Risk Index (RRI) framework that could contribute to the sustainable management of antifouling agents while accounting for local environmental conditions. Full article

Bacterial colonization and biofilm formation on orthopedic and dental implants remain major clinical complications, while conventional systemic antibiotics are often limited by poor penetration into biofilms and infected bone. These limitations have motivated the development of biomaterials with intrinsic antibacterial activity. Hydroxyapatite (HA), a major inorganic component of bone and teeth, possesses excellent biocompatibility, osteoconductivity, and bone-bonding ability but exhibits limited inherent antibacterial activity. Incorporation of therapeutic metal ions, including Ag⁺, Cu²⁺, Zn²⁺, Ti⁴⁺, Co²⁺, Ga³⁺, Sr²⁺, and Ce³⁺, has therefore emerged as a promising strategy for developing multifunctional HA-based biomaterials. This review critically examines the crystal-chemical basis of metal-ion incorporation into HA and discusses how ionic radius, oxidation state, charge-compensation mechanisms, dopant concentration, and synthesis conditions influence lattice occupancy, physicochemical properties, and biological performance. The antibacterial activity of metal-substituted and metal-modified HA systems generally involves interconnected mechanisms, including bacterial membrane damage, intracellular metabolic disruption, interference with enzymes and nucleic acids, reactive oxygen species (ROS)-mediated oxidative stress, and inhibition of bacterial adhesion and biofilm formation. Ag-, Cu-, Zn-, and Ga-containing HA systems show the most consistently reported antibacterial effects, although their efficacy and cytocompatibility depend strongly on dopant concentration and ion-release kinetics. Co-substituted HA may combine antibacterial activity with angiogenic and osteogenic stimulation, whereas Sr-substituted HA is primarily osteogenic and anti-resorptive, with variable antibacterial performance. Ti-modified HA and TiO₂/HA composites exhibit predominantly photoactive antibacterial behavior, while Ce-substituted HA shows concentration-, oxidation-state-, and synthesis-dependent biological effects. The review also evaluates protein adsorption, osteogenic and angiogenic signaling, macrophage-mediated immunomodulation, biological safety, and representative commercial and translational applications. Overall, metal-substituted HA represents a versatile platform for infection-resistant and regenerative hard-tissue biomaterials, provided that composition, phase structure, ion release, antibacterial efficacy, and cytocompatibility are systematically co-optimized before clinical translation. Full article

Photocatalytic degradation technology has been widely acknowledged for its low cost and high degradation efficiency. However, the loss, migration and difficult recovery of powdered catalysts are still critical bottlenecks for practical applications. In this study, silver nanoparticles (Ag NPs)/polyvinylidene fluoride (PVDF) photocatalytic composite membranes were in situ fabricated by incorporating AgNO₃ into a PVDF casting solution, followed by electrospinning and UV post-treatment. The resulting membranes exhibited sustained photocatalytic capability towards dyes and antibiotics. The optimal membrane achieved 89.6% and 83.0% degradation efficiency for chloramphenicol (CAP) and rhodamine B within 16 h under UV irradiation, respectively. Free radical trapping experiments revealed that the superoxide radical (·O₂⁻) dominated the photocatalytic degradation of CAP, and the mechanism of photocatalytic degradation was explored. Additionally, the Ag NPs/PVDF photocatalytic membrane demonstrated a distinct antibacterial efficacy against Staphylococcus aureus (S. aureus) with a distinct inhibition zone of 20 mm, effectively inhibiting bacterial proliferation. Full article

Background: Catheter-related bloodstream infections are common in patients receiving hemodialysis through a central venous catheter. Taurolidine, a novel broad-spectrum antimicrobial catheter lock solution, is FDA-approved in combination with heparin for reducing the incidence of such infections. Methods: In vitro activity of taurolidine was assessed against 442 bacterial and 50 yeast clinical bloodstream infection isolates selected from the SENTRY Antimicrobial Surveillance Program and tested according to the Clinical and Laboratory Standards Institute methodology. Multidrug-resistant species and phenotypes were included. Results: Taurolidine was highly active against all isolates, with MIC₅₀/MIC₉₀ values of ≤1024/1024 μg/mL for most species. The highest MICs observed were among isolates of Mycobacterium avium complex and Burkholderia cepacia complex (MIC₉₀, 2048 μg/mL) and Candida albicans (MIC₉₀, 4096 μg/mL). All isolates were inhibited by 13,500 μg/mL of taurolidine, the concentration of the commercially available product. Conclusions: Taurolidine activity was very similar among Gram-positive, Gram-negative, and yeast clinical isolates, with the activity of taurolidine being unaffected by phenotypic resistance to other antimicrobials. Taken together with clinical efficacy data from clinical trials, this provides a theoretical basis for the idea that taurolidine-based lock solutions may be able to reduce the risk of catheter-related bloodstream infections from a wide variety of pathogens and resistance phenotypes. Full article

Cowpea (Vigna unguiculata subsp. sesquipedalis, also known as yardlong bean) is an important winter horticultural crop in Hainan, and Fusarium wilt seriously threatens its yield and quality. To clarify the pathogen and screen antagonistic bacteria, surveys were conducted in 14 fields across Hainan’s major cowpea-growing areas. The causal agent was isolated, tested for pathogenicity, and identified using morphological and multigene molecular methods. Meanwhile, rhizosphere and endophytic bacteria from healthy plants were screened by dual culture, and candidate strains were phylogenetically analyzed using whole-genome sequencing (285 orthologous single-copy genes). Fusarium wilt occurred in all 14 fields (mean incidence 15.35%, range 3.20–76.40%). Of 44 fungal isolates, six were highly pathogenic and identified as Fusarium oxysporum. Twenty-two bacterial strains showed stable antagonism against F. oxysporum, with inhibition rates ranging from 42.62% to 68.47%. Phylogenetic analysis based on whole-genome sequences identified 15 Bacillus strains to the species level (12 B. velezensis, 2 B. subtilis, 1 B. tropicus), while the remaining seven strains belonged to Lysinibacillus (1), Pantoea (1), Klebsiella (1), Serratia (2), and Pseudomonas (2). Draft genome sequences of all 22 strains were obtained. This study provides a collection of biocontrol bacterial resources and genomic information for managing cowpea Fusarium wilt. Full article

Helicobacter pylori is one of the most common bacterial pathogens in humans and the primary etiological agent of chronic gastritis, peptic ulcer disease, and gastric cancer. Its ability to establish persistent gastric colonization relies on multiple virulence factors, including adhesins, urease, cytotoxins, motility, outer membrane vesicles, and biofilm formation, which collectively promote bacterial survival, chronic inflammation, and treatment failure. The increasing prevalence of antibiotic-resistant H. pylori strains has intensified the search for therapeutic strategies targeting both bacterial viability and virulence. Berberine (BBR), a natural isoquinoline alkaloid, has emerged as a promising candidate because of its antibacterial, anti-inflammatory, and antioxidant properties. Increasing evidence derived from native berberine, its derivatives, and berberine-based formulations indicates multifaceted anti-H. pylori activity, including direct antibacterial effects, inhibition of virulence determinants, and modulation of host inflammatory responses. This review summarizes current knowledge on the epidemiology and pathogenic mechanisms of H. pylori and provides a comprehensive overview of the available evidence regarding the anti-H. pylori pharmacological profile of BBR-based compounds. Particular attention is given to their effects on bacterial adhesion, motility, urease activity, efflux pump function, biofilm formation, and host inflammatory signaling pathways. The review also discusses findings from preclinical and clinical studies supporting BBR-based strategies as adjuncts to conventional eradication therapies. In addition, recent advances in nanotechnology-based drug delivery systems designed to overcome the poor oral bioavailability of BBR and improve its therapeutic efficacy against H. pylori are highlighted. Full article