Search Results (8,960)

Background/Objectives: The widespread use of mupirocin and fusidic acid for the treatment and decolonization of Staphylococcus aureus (SA) skin infections has led to a rapid emergence of resistant strains, limiting the effectiveness of the few topical agents currently available for clinical use. Methods: In this study, we evaluate Fe(tropo)₃, a neutral and lipophilic iron(III)–tropolone complex, as a non-antibiotic topical antimicrobial candidate for the management of drug-resistant SA skin and soft tissue infections. Results: Fe(tropo)₃ exhibits potent in vitro activity against methicillin-susceptible SA, methicillin-resistant SA (MRSA), vancomycin-intermediate SA, and strains with high-level resistance to mupirocin and fusidate, with minimum inhibitory concentrations of 2 µg/mL across all tested isolates. The compound effectively penetrates bacterial cells, induces intracellular iron accumulation, and triggers dose-dependent reactive oxygen species generation, resulting in rapid bacterial killing and significant antibiofilm activity. Importantly, Fe(tropo)₃ shows a slower development of resistance compared with ciprofloxacin and displays synergistic activity with oxacillin against MRSA. When formulated as a 1% topical ointment, Fe(tropo)₃ significantly reduces bacterial burden in a murine excisional wound infection model, achieving a 98% ± 1% reduction in SA load without detectable hemolysis or skin irritation. Conclusions: These pilot study results support Fe(tropo)₃ as a clinically relevant, mechanism-distinct topical antimicrobial with potential utility in settings where resistance to existing topical antibiotics compromises standard care. Full article

Fungicide contamination is an increasing global environmental concern, due to the harm they may pose to non-target organisms, their contribution to antimicrobial resistance, and the potential risks to human health when drinking water (DW) sources are impacted. Many fungicides used in agriculture are chiral and may exist as racemates, or a combination of diastereoisomers and/or enantiomers. Since enantiomers can differ in environmental fate, distribution, and toxicity, enantioselective analysis of chiral fungicides is crucial. The aim of this study was to develop and validate an analytical method for the determination of azole chiral and achiral fungicides in DW using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). Chromatographic separation of one achiral fungicide and five chiral fungicides was achieved using a polysaccharide chromatographic column under reverse elution mode. The validated method demonstrated high sensitivity with method detection limits (MDL) below 0.86 ng L⁻¹ and was successfully applied to 13 DW samples collected from various supply networks across Portugal. Seven out of the 15 targeted analytes were found at trace concentrations (>MDL). Fluconazole was the most frequently detected (~87% of the samples). The hazard quotients (HQs) for individual compounds for each individual fungicide (sum of the enantiomers for those chiral) and the hazard index (HI, sum of the individual HQ values) were calculated in each DW sample, indicating no significant health risks to consumers, since it is well below 0.1 for all compounds. Full article

Kombucha, a traditionally fermented tea, has gained increasing scientific and commercial interest due to its sensory quality and bioactive metabolites profile associated with different health-related activities. Recent research highlights the value of enriching traditional and honey kombucha with plant-based biomolecules to create new functional beverages with enhanced functional and nutraceutical properties, improved flavor, and chemical stability. Therefore, this study aimed to review and update the research on the enrichment of kombucha with these natural biomolecules that have been shown to expand the spectrum of health-promoting activities (e.g., antioxidant, antimicrobial, anticancer, and anti-aging), while also enhancing the physicochemical stability of raw kombucha. Yet this innovation must be navigated with a thoughtful understanding of safety, biochemical stability, and sensory evaluation. Thus, this review strongly advocates that the integrative enrichment approach presents a promising strategy for developing next-generation functional beverages with synergistic nutritional and therapeutic benefits. Further controlled studies are needed to elucidate the mechanistic interactions between the kombucha’s microbiome and these added bioactive substrates, as well as to optimize formulations for targeted health applications. Full article

Silver nanoparticles (AgNPs) are among the most widely used type of nanoparticles due to their antimicrobial properties. While their application in disease treatment is well established, less is known about their ecological effects after they are released into ecosystems, where they may affect microorganisms and disrupt ecological balance. A green synthesis using Sambucus nigra fruit extract was applied to prepare AgNPs of two sizes, and their interactions with Brevundimonas vesicularis USM1, Pseudarthrobacter oxydans USM2, Pseudomonas putida USM4, Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853 were examined. The nanoparticles were characterized by UV–Vis, TEM, and DLS, and microbial growth was assessed using microplate assays and colony enumeration. No significant inhibition of E. coli ATCC 10536, S. aureus ATCC 25923, or P. aeruginosa ATCC 27853 was observed in the presence of small (22 nm) or large (66 nm) AgNPs. Growth inhibition occurred in P. oxydans USM2 and P. putida USM4 exposed to small AgNPs, and in B. vesicularis USM1, P. oxydans USM2, and P. putida USM4 exposed to large AgNPs. The strain-specific responses indicate a size-dependent impact on bacteria, suggesting potential effects on microbiome structure and function. This study provides insights supporting environmental risk evaluation and safer-by-design development of AgNP-based materials. Full article

Listeria innocua is a bacterium frequently detected in food and food production plants (FPPs). Understanding the heterogeneity of L. innocua food isolates is essential for predicting potential food safety threats and developing preventive and control measures. This study aimed to characterize L. innocua isolated from raw drinking milk by investigating the genomic features related to virulence, antimicrobial resistance, and persistence using whole-genome sequencing (WGS), along with phenotypic antimicrobial susceptibility testing using the disk diffusion method. All ten isolates analyzed in this study belonged to sequence type (ST) 492 and were distantly related to the reference strain. A total of 80 virulence-associated genes were identified, including the complete Listeria Pathogenicity Islands-3 (LIPI-3) and LIPI-4 clusters typically found in virulent L. monocytogenes clones, as well as 66 additional genes involved in adhesion, invasion, motility, post-translational modification, regulation, immune modulation, and stress survival. Stress survival islet 2 (SSI-2) and genes encoding the Clp protease complex (clpC, clpE, clpP), which support both persistence and virulence, were also detected, whereas LIPI-1 and internalin genes were not detected. The antimicrobial resistance determinants included fosX, lin, norB, sul, and three multidrug efflux pumps (lde, mdrL and mdrM). Mobile genetic elements (plasmids, prophages, or transposons) were not detected. All isolates were phenotypically susceptible to benzylpenicillin, ampicillin, meropenem, erythromycin, and trimethoprim–sulfamethoxazole. These findings underscore the importance of ongoing genomic surveillance of L. innocua in food environments and highlight the need to assess the potential risk posed by specific lineages, such as ST492, to food safety. Full article

The development of collagen-based composite materials offers new opportunities for designing bioactive porous structures with tunable properties. This study focuses on sponges or scaffolds fabricated from fish skin-derived tropocollagen combined with detonation nanodiamonds (NDs), aiming to explore how incorporation of NDs and application of radiation, as a potential sterilization method, influence structural and functional characteristics of the material. Freeze-dry methods of sponge fabrication resulted in a bilayered structure of open porosity, with microporosity at the top and a microchannel at the lower part of the material. The sponges demonstrated mechanical properties with relatively low elongation of below 10%, while the maximum stress was reduced by ca. 20% due to irradiation. Hydration and absorption experiments, mimicking the resorption of collagen in physiological conditions of expected application as wound dressing material, demonstrated controllable fluid uptake and gradual material dissolution, taking place over several hours, depending essentially on the irradiation treatment and morphological characteristics of the sponge. These findings highlight the versatility of collagen–nanodiamond composites as platforms, in which structural design and processing parameters control performance. Moreover, they provide a strong indication of the expected behavior of collagen–nanoparticle systems, including those incorporating NDs modified to impart specific biological functionality, such as antimicrobial activity. Full article

This study developed and evaluated multifunctional Cu-doped Zeolitic Imidazolate Framework-8 nanoparticles coated with hyaluronic acid (Cu-ZIF-8@HA) for antimicrobial application on stainless-steel food-contact surfaces. Structural characterization through SEM, TEM, and elemental mapping confirmed the successful synthesis, uniform Cu incorporation, and HA coating without compromising the crystalline ZIF-8 framework. Cu doping reduced particle size (~130 nm) and enhanced redox activity, while HA encapsulation improved colloidal stability and biocompatibility by shifting zeta potential from positive (+22.1 mV) to negative (−18.7 mV). Cytotoxicity assays demonstrated that HA significantly mitigated metal-induced toxicity, maintaining >70% cell viability at ≤1000 µg/mL. Antibacterial assessments revealed potent activity against Salmonella Typhimurium ATCC 14028 and Escherichia coli O157:H7, with Cu-ZIF-8@HA exhibiting the largest inhibition zones (18.15–20.33 mm), lowest MIC/MBC values (500/2000 µg/mL and 1000/2500 µg/mL), and over 6-log reductions in bacterial adhesion on stainless steel. Enhanced wettability (contact angle 11.77°) and surface energy (64.42 mN/m) further facilitated antimicrobial contact. These results confirm that Cu-ZIF-8@HA integrates the oxidative potency of Cu, the structural stability of ZIF-8, and the biocompatibility of HA, offering a promising and safe nanomaterial platform for controlling bacterial contamination and biofilm formation in food-processing environments. Full article

Background/Objectives: The healing rate of wounds resulting from postoperative abdominal surgery interventions increases as the inflammation and infections in the wound are reduced. However, antibiotic resistance among microorganisms increases the incidence of surgical site infections (SSIs). Therefore, the need for new products that exhibit antimicrobial and anti-inflammatory activities, in addition to antibiotics, is increasing. Methods: Silver nanoparticles (CO-AgNPs) were obtained using the green synthesis technique with Cydonia oblonga L. leaves, which constitute a significant amount of waste, and the effects of the obtained nanoparticles on in vitro wound healing were determined. Results: It was observed that CO-AgNPs inhibited myeloperoxidase and collagenase, enzymes that negatively affect wound healing. Furthermore, they exhibited good antimicrobial activity against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus, which are common hospital pathogens. The CO-AgNPs could exhibit enhanced wound-healing properties by inhibiting microorganisms. Conclusions: It was clear that the development of new, environmentally friendly, and biocompatible products containing CO-AgNPs could be feasible, particularly for wound healing following infected abdominal surgery. Full article

The objective of this study was to evaluate relationships between antimicrobial use (AMU) and antimicrobial resistance (AMR) in isolates from farmed Atlantic salmon that could represent finfish pathogens in the British Columbia (BC) aquaculture industry using historical surveillance data. Antimicrobial susceptibility data were obtained for 1040 bacterial isolates from farmed Atlantic salmon submissions to the BC Animal Health Centre for 2007–2018. Antimicrobial use data were provided by the BC Ministry of Agriculture and Food from feed mill prescriptions for BC farmed Atlantic salmon for 2007–2018. Multivariable logistic regression models for all bacterial isolates with a random intercept for species were developed to determine associations with outcomes of resistance to trimethoprim-sulfadiazine (SXT), oxytetracycline (OXY), and florfenicol (FLOR). Resistance to SXT, FLOR, and/or OXY were all significantly associated with each resistance outcome in their respective models. Only the SXT resistance model was significantly associated with AMU, specifically potentiated sulfonamide use, but use was not significantly associated with AMR for any other resistance outcome. The results of this study contribute to the rapidly growing and increasingly pertinent body of literature on AMU and AMR in the unique marine aquaculture environment. Future research at the farm level linking pen-specific AMU to AMR outcomes will provide more understanding of selection pressure for AMR at the local level and provide more guidance for antimicrobial stewardship in finfish aquaculture. Full article

Antimicrobial resistance (AMR) has become a major global public health challenge, and widely residual disinfectants in the environment are one of the key drivers of bacterial AMR development. This study aimed to investigate the inductive effects of three commonly used disinfectants—benzalkonium bromide (BAB), glutaraldehyde (GTA), and povidone-iodine (PVP-I)—on the resistance of Escherichia coli (E. coli), as well as the resultant bacterial phenotypic and genetic alterations. Three disinfectants frequently detected in clinical and environmental settings were selected as the research objects: first, their bactericidal efficacy against environmental bacteria was determined; subsequently, a concentration-increasing gradient approach was adopted to systematically explore the evolutionary patterns of E. coli resistance under the stress of sub-inhibitory concentrations (SICs). After induction, the bacterial resistance levels to disinfectants and various antibiotics, growth characteristics, and biofilm-forming ability were detected, and combined with whole-genome analysis to investigate genetic-level changes. The results showed that all three disinfectants could enhance E. coli resistance to themselves (12–48-fold) and antibiotics, and the induced antibiotic resistance exhibited favorable genetic stability. Among them, BAB induced the strongest resistance, with the most significant increase in resistance levels to multiple antibiotics (16–64-fold); GTA had the weakest inductive effect, only slightly enhancing bacterial resistance to a small number of antibiotics. Notably, all induced strains exhibited reduced growth rates yet markedly enhanced biofilm-forming capacity, alongside acquired genomic structural variations. Their gene functions displayed shared adaptive signatures in coping with environmental stress, while core pathogenicity-associated genes remained conserved. This study demonstrates that inducing E. coli using environmentally relevant low concentrations of disinfectant residues as initial induction doses drives the evolution of bacterial antimicrobial resistance (AMR), with distinct resistance induction risks among the three disinfectant types. These findings offer critical insights for standardizing disinfectant application, mitigating the transmission of bacterial AMR, and underscore the imperative of interdisciplinary collaboration to tackle the environmental risks posed by disinfectant residues. Full article

Southeast Asia (SEA) harbors one of the world’s richest reservoirs of marine biodiversity, offering immense potential for natural product discovery. This review presents a comprehensive survey of sponge-derived marine natural products (MNPs), with notable activity, reported from SEA over the past two decades, highlighting their chemical diversity, biological activities and regional research trends. Analysis of the past two decades of MNPs data reveals that sponges (Phylum Porifera) remain the dominant source of new MNPs, representing nearly half of all discoveries in the region. Indonesia, Vietnam, and Thailand are leading contributors, with Indonesia exhibiting the highest productivity but limited local research leadership. The South China Sea and Indonesian archipelagos emerge as biodiversity and bioprospecting hotspots, yet large areas remain underexplored. Bioactive metabolites isolated from SEA sponges demonstrate potent anticancer, antimicrobial, anti-inflammatory, antiviral and enzyme-inhibitory properties, underscoring their value for pharmaceutical innovation. Despite this promise, uneven research capacity, infrastructure gaps and environmental degradation constrain sustainable exploitation. By consolidating recent advances in lead compound development and identifying key taxonomic as well as geographic priorities, this review strengthens the scientific foundation for marine drug discovery in SEA and supports integration of bioprospecting with regional Blue Economy and biodiversity conservation agendas and programs. Full article

Background: The global transcriptome reprogramming in grapevines in response to powdery mildew remains poorly understood, despite its economic implications, especially the new cultivars. Methods: Thus, this study aimed to elucidate these changes through RNA sequencing in ‘Yeniang No. 2’ grapevine leaves infected with powdery mildew compared to healthy ones. Results: A total of six samples were subjected to transcriptome sequencing, resulting in 36.85 Gb of clean data. A minimum of 5.89 Gb of clean data was generated for each sample, with at least 92.24% of the clean data attaining a quality score of Q30. Clean reads from each sample were aligned to the designated reference genome. The mapping ratio varied between 88.77% and 89.66%. The high-quality sequencing data revealed 1219 differentially expressed genes (DEGs), of which the infection upregulated 790 and downregulated 429. Functional enrichment analyses revealed a significant activation of key defense-related pathways. These included plant–pathogen interaction, phenylpropanoid and flavonoid biosynthesis for creating antimicrobial compounds, glutathione metabolism for reducing oxidative stress, and oxidative phosphorylation for enhanced energy production. This indicates a coordinated, multi-faceted defense strategy. The study also uncovered a complex layer of post-transcriptional regulation, identifying 1883 novel genes and 22,210 alternative splicing events, primarily skipped exons and intron retention. Key hub proteins identified within interaction networks, along with these splicing changes, underscore a sophisticated defense involving transcriptional reprogramming and metabolic shifts. Conclusions: The genes and molecular markers discovered are valuable resources for marker-assisted breeding. Leveraging these findings, particularly hub genes and favorable splice variants, can accelerate the development of new grapevine cultivars with durable resistance to powdery mildew. Full article

Currently, the packaging sector must continue developing more sustainable systems to reduce the high quantities of single-use plastic waste generated. This study evaluated the production and characterization of bio-based composite trays with antimicrobial activity. Different formulations of polybutylene adipate co-terephthalate (PBAT) and polylactic acid (PLA) with polyethylene glycol (PEG) as plasticizer and citric acid as a compatibilizer/crosslinker were evaluated, in addition to the inclusion of plantain microfibers (PFs), TiO₂, and menthol as reinforcing and antimicrobial agents, respectively. The mixtures were subjected to pellet extrusion (165/175/185/190 °C and 60 rpm) and then to flat sheet extrusion (at 185/190/195/205 °C and 60 rpm), besides calendering (at 3.5–6.0 rpm). A single-screw extruder was used in both cases. The obtained sheets (0.317 ± 0.040 mm thick and 17 cm wide) were molded into 12.5 × 11.0 × 3.5 cm trays in a thermoforming machine (at 325 °C and vacuum pressure). For the resulting composite sheets and trays, measurements of mechanical strength, moisture absorption, barrier (WVTR), transmittance, and color were performed. FT-IR, DSC, TGA, SEM, and in vitro antimicrobial tests were also conducted. Based on these tests, an initial formulation with an 85/15 (w/w) PLA/PBAT ratio was defined, which was then reinforced with 3% (w/w) PF. Furthermore, the inclusion of 5% (w/w) menthol in the composite led to fungistatic activity against Botrytis cinerea, also resulting in homogeneous sheets (tensile strength 24.137 ± 1.439 MPa) and trays (compressive strength 0.113 ± 0.010 MPa). These findings can be applied to the packaging and preservation of perishable produce. Full article

Lignin, the second-most-abundant polymer on Earth, has attracted attention for its value-added applications. Colloidal lignin particles can overcome handling and compatibility issues, offer antioxidant, antimicrobial, and UV-protective properties, and serve as Pickering stabilizers. Plant extracts rich in bioactive compounds, such as polyphenols and flavonoids (e.g., quercetin), can further enhance lignin-based formulations. In this context, colloidal lignin–quercetin particles (CLQPs) were produced for the first time via antisolvent precipitation and used as Pickering emulsion stabilizers. CLQP dispersions (30 g/L) were prepared by solubilizing lignin and quercetin in 80% (v/v) aqueous acetone solution, followed by precipitation with a pH 8 buffer. A quercetin content of 50% (w/w) (CLQP-50) resulted in predominantly round-shaped lignin–quercetin particles (<1 µm) with a small fraction of quercetin crystals. Both structures contributed to emulsion stabilization, as evidenced by confocal microscopy, a three-phase contact angle of 91.6 ± 0.1°, and a zeta potential of −52.8 ± 2.7 mV. CLQP-50 successfully stabilized Pickering emulsions at a 60/40 oil/water ratio, showing high physical stability (stability index 0.01) and shear-thinning behavior with gel-like consistency. These findings demonstrate the pioneering development of lignin–quercetin hybrid colloidal particles as sustainable and functional Pickering stabilizers, opening new opportunities for advanced cosmetic and pharmaceutical formulations. Full article

This study aimed to develop a solvent removal-based in situ forming gel (ISG) loaded with salicylic acid (SAL) using myristic acid (MYR) as a matrix-forming agent. SAL-loaded MYR-based ISGs were prepared using N-methyl-2-pyrrolidone (NMP) or dimethyl sulfoxide (DMSO) as solvents and evaluated for physicochemical properties, matrix formation behavior, mechanical characteristics, and in vitro drug release. Increasing MYR content influenced viscosity, gel formation kinetics, and depot integrity, resulting in prolonged SAL release of up to 20 days in DMSO-based formulations. The release kinetics were best described by the Peppas–Sahlin model, indicating diffusion-dominated drug transport. The selected formulation containing 30% w/w SAL and 20% w/w MYR exhibited acceptable injectability, reproducible in situ matrix formation, and sustained drug retention. Antimicrobial testing confirmed that SAL retained biological activity against oral pathogens following incorporation into the ISG system, although solvent contributions to antimicrobial effects were also observed. These findings demonstrate the feasibility of a MYR-based ISG system in which SAL contributes to both therapeutic activity and matrix formation, supporting its potential for localized oral drug delivery. Full article