Search Results (10,335)

Antimicrobial resistance (AMR) represents a critical global health challenge, with methicillin-resistant Staphylococcus aureus (MRSA) posing a significant threat in both hospital-acquired and community-associated infections. Research has demonstrated that biofilm formation is a key factor contributing to drug resistance in MRSA. In this study, we investigated an fungus, Fusarium oxysporum BPF55, isolated from Blaps rynchopetera, which inhibits MRSA biofilm formation. The aim of this research was to identify the fungal strain and comprehensively characterize its genomic features, as well as to evaluate its anti-MRSA biofilm potential. Whole-genome sequencing revealed a genome size of 50,097,681 base pairs, a GC content of 47.36%, and 16,507 predicted coding genes. AntiSMASH analysis identified 56 secondary metabolite biosynthetic gene clusters, including those involved in the synthesis of various natural products such as terpenes, non-ribosomal peptides, and polyketides. Using UPLC-MS/MS, 15 compounds were annotated from the ethyl acetate extract. Molecular docking studies demonstrated that four compounds exhibit varying affinities for SarA and AgrA, two key proteins involved in MRSA biofilm formation. Overall, these findings suggest that the fungus F. oxysporum BPA55 produces a variety of secondary metabolites and contains bioactive compounds with potential anti-MRSA biofilm activity. Full article

Background: Staphylococcus aureus bacteremia (SAB) is a common and life-threatening bloodstream infection often caused by methicillin-resistant SA (MRSA) isolates. Up to 35% of SAB patients fail to clear infection with gold-standard anti-MRSA antibiotics, even if the isolate meets susceptibility breakpoints in conventional assays in vitro. Such outcomes are termed persistent and may involve small colony variant (SCV) adaptation of SA in vivo. Methods: In this study, we assessed virulence phenotypes and mechanisms in persistent (PB) vs. resolving (RB) MRSA isolates from SAB. Results: Overall, PB isolates caused less hemolysis or biofilm formation than RB isolates, but proteolysis was equivalent. Attenuation of these virulence phenotypes increased longitudinally during the course of SAB. Although PB vs. RB isolates had similar human endothelial cell invasion rates, PB isolates more frequently formed SCVs intracellularly and inversely correlated with pH. Study PB and RB isolates exhibited distinct susceptibilities to prototypic human host defense peptides (HDPs), which were influenced by antibiotics and pH. Furthermore, mechanistic signatures of HDPs differed between PB and RB isolates. Conclusions: Together, these results reveal that MRSA isolates from PB vs. RB outcomes of SAB have differential virulence profiles that suggest coordinated immune subversion in PB. Understanding MRSA adaptations that promote persistence in SAB may enable innovative agents and strategies to address these challenging infections. Full article

Native Staphylococcus aureus protein A exhibits strong affinity to the Fc and VH regions of human IgG1, IgG2, and IgG4, making it a valuable tool for monoclonal antibody (mAb) purification. However, its low stability under conditions such as increased alkaline concentrations during cleaning-in-place (CIP), protease exposure, thermal stress, and shear forces limits its usability for large-scale industrial applications. Recombinant Protein A (rProtein A) can be modified to improve key properties, including alkaline stability. In this study, we present targeted modifications to the C domain of native Protein A, evaluating multimeric variants for structural and functional improvements. The selected variant demonstrated extremely high stability after 60 h incubation at 0.5 M NaOH by maintaining more than >90% initial dynamic binding capacity (DBC) and up to 80% DBC after 40 h in 1.0 M NaOH. However, the most impressive result obtained was the stability of the ligand in 1.5 M NaOH, retaining 80% DBC after 22 h and 60% DBC after 40 h. To the best of our knowledge, this is the first time that such high alkaline stability is reported for a rProtein A. To assess its application in monoclonal antibody purification, the optimized rProtein A ligand was immobilized on agarose resin and tested in chromatography processes. The resulting chromatography resin functionalized with the CmZmb ligand (now commercialized by Sunresin, China under the name of rProtein A Seplife Suno) exhibited a high dynamic binding capacity of 70 mg/mL, minimal ligand leaching under operational conditions (~15 ppm), and extended lifecycle performance (88% DBC retained after 120 purification cycles with 0.5 M NaOH CIP), making it well-suited for industrial-scale applications. Full article

Background: The increasing antimicrobial resistance has led to a greater demand for alternative treatment options, which in turn has increased interest in naturally occurring biomolecules such as pyocyanin. Methods: In this study, a three-factor Box–Behnken Design (BBD)-based response surface methodology (RSM) was employed to optimize the effects of glycerol, peptone, and pH on pyocyanin production by Pseudomonas aeruginosa OG1. The antimicrobial efficacy of the optimized pyocyanin was subsequently evaluated in vitro against three Candida species and four clinically important bacterial pathogens using the disk diffusion method, with gentamicin and fluconazole used as positive controls. Results: The second-order polynomial model demonstrated excellent fit (F = 176.3, p < 0.0001) with a non-significant lack of fit, indicating adequate representation of the experimental data. The optimal conditions were determined to be glycerol at 1.11% (w/v), peptone at 17.86 g/L, and a pH of 7.27, yielding a predicted pyocyanin concentration of 25.92 mg/L. Antimicrobial testing revealed broad-spectrum, dose-dependent activity against all tested microorganisms. The highest efficacy was observed against Bacillus cereus (26.4 ± 1.3 mm at 40 µg/mL), followed by Candida glabrata (21.5 ± 1.6 mm), Klebsiella pneumoniae (17.6 ± 1.4 mm), Candida albicans (15.4 ± 1.8 mm), Candida parapsilosis (13.2 ± 1.9 mm), Proteus mirabilis (12.5 ± 1.3 mm), and MRSA Staphylococcus aureus (9.2 ± 1.1 mm). Conclusions: These findings demonstrate that BBD-based RSM is a robust approach for optimizing pyocyanin production and that pyocyanin represents a promising dose-dependent antimicrobial agent against susceptible pathogens. Full article

In this work, we demonstrate a functional and previously insufficiently explored route for converting cyclic olefin copolymer (COC) TOPAS^® thin films into antibacterial hybrid materials through a combination of solvent casting, plasma activation, noble-metal sputtering, and subsequent thermal or laser treatment. While COC is already well-known as a transparent, chemically resistant material for pharmaceutical and optical applications, its coupling with post-treated noble-metal nanostructures for antibacterial functionality has not been systematically described. The main contribution of this study lies in showing that COC can serve not only as a passive packaging substrate, but also as an active platform for the formation of biologically relevant surface nanostructures. Compared with previously reported metal/polymer systems, the present work provides clear evidence that noble-metal layers on COC undergo substantial structural evolution after thermal and excimer-laser treatment, resulting in regular nanoclustered morphologies. A particularly important finding is the detection of Au particle implantation below the COC surface during sputtering, as revealed by Rutherford backscattering spectrometry, which distinguishes this system from conventional surface-only metal coatings. Furthermore, we show that laser and thermal processing do not merely reshape the deposited layer, but significantly influence the final biological response of the material. Ag-based structures showed strong bactericidal behavior against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The prepared samples were comprehensively characterized by AFM, DSC, RBS, SEM, and TGA, and their roughness and wettability were also evaluated, enabling direct correlation between physicochemical changes and antibacterial performance. These results introduce a new strategy for upgrading conventionally used pharmaceutical COC materials into multifunctional surfaces with added antibacterial value. Full article

Humulus lupulus L. (hops), belonging to the Cannabaceae family, is grown mainly for brewing, with 98% of global production directed to this sector. Moreover, large volumes of female cone residues are generated as by-products, representing a valuable source of bioactive compounds that can be valorized under green chemistry principles. This study aimed to extract bioactive compounds from hop cone residues sourced from craft breweries using ultrasound-assisted (EH-UA) and microwave-assisted (EH-MA) extraction methods. Hydroalcoholic extracts (70%) were analyzed for chemical composition, antioxidant, antimicrobial, antiproliferative, nitric oxide (NO)-production inhibition, and photoprotective activities. GC-MS identified 32 compounds in EH-MA and 30 in EH-UA, including terpenes, sesquiterpenes, oxygenated sesquiterpenes, and fatty acids. Both extracts demonstrated strong antioxidant activity in cell-based (TBARS, OxHLIA) and chemical (DPPH, ABTS, FRAP) assays, particularly EH-MA. Significant antibacterial activity was observed, especially against Enterobacter cloacae, Pseudomonas aeruginosa, and Staphylococcus aureus (MIC 1–10 mg/mL), as well as antifungal activity against Aspergillus brasiliensis (MIC 2–2.5 mg/mL). Selective antiproliferative activity was observed against tumor cell lines Caco-2 and MCF-7 (GI₅₀ 25 μg/mL), without cytotoxicity toward nontumor cell lines Vero and PLP2 (GI₅₀ > 400 μg/mL). All extracts inhibited the production of the inflammation mediator NO, with EH-MA showing the most potent effect (IC₅₀ of 35 μg/mL), followed by EH-UA (IC₅₀ of 55 μg/mL). Photoprotective potential was also demonstrated, with SPF values of 19 (EH-MA) and 18 (EH-UA). In conclusion, hop cone residues can yield multifunctional extracts with antioxidant, antimicrobial, antiproliferative, anti-inflammatory, and photoprotective activities, which support their sustainable upcycling for pharmacological, nutraceutical, and cosmetic applications. Full article

Background/Objectives: Teucrium polium L. is widely used in traditional medicine and has been proposed as a source of antimicrobial adjuvants in the context of antimicrobial resistance. Here, we characterized the essential oil (EO) and polar extracts of T. polium and evaluated their antioxidant activity, antimicrobial potency against clinical multidrug-resistant (MDR) isolates, and the interaction of the EO with conventional antibiotics using a chequerboard assay (FICI); further, we investigated in silico molecular interactions with some targets related to resistance. Methods/Results: The EO, which was hydrodistilled and subsequently analyzed by GC–MS, is characterized by dominant limonene content (24.13%) and contents of oxygenated sesquiterpenes such as β-eudesmol (10.48%) and α-muurolol (8.10%). HPLC/UV–ESI–MS characterization of the extracts (decoction and Soxhlet) demonstrated that they were rich in polyphenolic compounds and flavonoids, which matched the standard phytochemical characteristics of this species. The extracts exhibited significant reducing capabilities, and the hydroethanolic extract exhibited the highest antioxidant activity (DPPH IC₅₀ = 15.41 μg/mL; FRAP EC₅₀ = 30.65 μg /mL), while the EO revealed at most moderate capacity in these tests. In antimicrobial assays, the EO inhibited fungi more effectively than the extracts (MIC of 1.17 mg/mL against Aspergillus niger; 4.69 mg/mL against Candida spp.), while antibacterial MICs for both the EO and extracts were generally high (up to 50 mg/mL). Combination testing nevertheless identified synergistic or additive effects of the EO with selected antibiotics, notably with ceftazidime against ESBL-producing Escherichia coli (FICI = 0.141) and Staphylococcus aureus (FICI = 0.039) and with amikacin against Klebsiella pneumoniae (FICI = 0.313); the EO–ceftriaxone pairing against ESBL E. coli was additive (FICI = 0.516). Docking simulations further supported these observations by showing the favorable predicted binding of oxygenated sesquiterpenes, most notably β-eudesmol and α-muurolol (up to −8.6 kcal/mol), to resistance-related targets such as RND efflux pumps, β-lactamases, and porins. Conclusions: Taken together, the in vitro and in silico data suggest that T. polium could be explored as a natural antimicrobial option and as an adjuvant to enhance antibiotic activity against multidrug-resistant pathogens. Full article

Curvularins, a class of macrocyclic lactones, have cytotoxic, antimicrobial, and anti-inflammatory properties. Curvularin, a 12-membered macrolactone, was used as a scaffold to design and synthesize structurally modified analogues to investigate structure–activity relationships and improve biological efficacy. Three series of curvularin-based analogues, Cur-5H-OMe, Cur-4P-OMe, and Cur-OMe, were synthesized with the same core structure but different substituent sizes and positions. Nine representative derivatives were evaluated for anti-inflammatory, anticancer, antibacterial, and antifungal activities. In LPS-stimulated RAW 264.7 macrophages, most compounds inhibited nitric oxide (NO) production in a concentration-dependent manner but exhibited cytotoxicity at high concentrations. Cytotoxicity assays against HaCaT cells and human cancer cell lines (HCT116, HeLa, and A375) revealed limited selectivity toward cancer cells. Antimicrobial evaluation indicated selective activity against the Gram-positive bacteria, Staphylococcus aureus. Compound 23 exhibited superior antibacterial potency compared with kanamycin and notable antifungal activity against Candida albicans. This study provides a versatile synthetic platform and identifies key structural features of curvularin derivatives, demonstrating their potential as anti-inflammatory and antimicrobial lead compounds. Full article

Background: Oxygen–ozone (O₂–O₃) therapy is a minimally invasive treatment for discogenic lumbar pain. Although rare, spinal infections—specifically spondylodiscitis—have been reported following intradiscal injections. To date, Lactobacillus iners has not been described as a causative agent in this context. Case Presentation: A 55-year-old immunocompetent woman presented with progressive lumbosciatica and elevated inflammatory markers three months after intradiscal O₂–O₃ therapy. MRI revealed L4–L5 spondylodiscitis with paravertebral involvement. Surgical biopsy confirmed L. iners as the pathogen. She underwent decompression and received targeted intravenous antibiotics, achieving full clinical and radiological recovery. Methods: A systematic literature review was performed using PubMed, MEDLINE, and Scopus to identify reports of spondylodiscitis following oxygen–ozone therapy. Six cases were included based on predefined inclusion criteria. Results: The 8 identified cases involved a range of pathogens, including Staphylococcus aureus, Streptococcus beta-haemolyticus, Escherichia coli, Achromobacter xylosoxidans, Mycobacterium abscessus, and Streptococcus intermedius, and one culture-negative infection. Clinical presentations varied from radiculopathy to sepsis. Management strategies encompassed both conservative (antibiotics alone) and surgical approaches, depending on neurological status and abscess formation. Outcomes were favorable in all cases except one fatality. Conclusions: This report is the first to describe L. iners spondylodiscitis in an immunocompetent patient following O₂–O₃ therapy. Clinicians should vigilantly evaluate post-infiltration spinal infections, maintain a low threshold for imaging and biopsy, and implement pathogen-targeted antibiotic regimens, with surgical intervention as needed. Full article

Background: Calcaneal fractures are complex injuries frequently associated with significant soft tissue damage and a high risk of post-operative complications, particularly infection. Despite advances in surgical techniques, infectious complications remain a major cause of morbidity and can severely compromise functional outcomes. The aim of this systematic review was to analyze the incidence, management strategies, and clinical impact of infectious complications following surgical treatment of calcaneal fractures. Methods: A systematic literature search was conducted in MEDLINE, Scopus, and Web of Science in accordance with PRISMA guidelines, including studies published up to May 2025. Randomized controlled trials and prospective and retrospective cohort studies involving adult patients surgically treated for calcaneal fractures and reporting post-operative infectious outcomes were included. Data extraction focused on patient demographics, fracture characteristics, surgical techniques, infection rates, microbiological findings, management strategies, complications, and functional outcomes. Methodological quality and risk of bias were assessed using the MINORS score. Due to substantial heterogeneity, results were synthesized descriptively. Results: Forty studies met the inclusion criteria, encompassing 5343 patients and 4638 surgically treated calcaneal fractures. Displaced intra-articular fractures predominated, with Sanders type II and III accounting for 79.8% of classified fractures, while Sanders type IV fractures represented 20.2% and were associated with higher complication rates. The overall post-operative infection rate was 9.4%, including 6.3% superficial surgical site infections and 3.0% deep infections. Open fractures accounted for 7.5% of reported cases and demonstrated markedly higher infection rates than closed injuries. Deep infections frequently required implant removal (62%), prolonged intravenous antibiotic therapy (100%), and additional surgical procedures (71%). Staphylococcus aureus, including methicillin-resistant strains, was the most commonly isolated pathogen. Functional outcomes were consistently worse in patients who developed infections. Conclusions: Infectious complications remain a clinically significant problem following surgical treatment of calcaneal fractures, particularly in severe fracture patterns, open injuries, and patients with relevant comorbidities. Deep infections are associated with substantial morbidity and inferior functional outcomes. Optimization of patient-related risk factors, careful surgical planning, and the selective use of minimally invasive approaches may help reduce infection risk. Further high-quality prospective studies with standardized outcome measures are needed to define optimal management strategies. Full article

Background: Accurate estimation of the postmortem interval (PMI), the time elapsed between death and body discovery, is a critical challenge in forensic science due to the complex interplay of factors affecting decomposition. Traditional methods based on macroscopic changes often lack precision, especially in later postmortem stages. Methods: This study aimed to develop a novel PMI estimation framework by integrating the dynamics of endogenous small non-coding RNAs (sncRNAs) and exogenous bacterial-derived small RNAs (sRNAs) using sRNA transcriptomics and machine learning. Results: Cardiac RNA degradation strongly correlated with PMI, with a random forest (RF) model achieving high accuracy (coefficient of determination (R²) = 0.939, mean absolute error (MAE) = 2.987 h). Employing PANDORA-seq, we profiled temporal changes in sncRNAs (miRNAs, tsRNAs and piRNAs) in postmortem cardiac tissue within 30 h in a mouse model, while simultaneously assessing RNA integrity (RIN) across eight organs. PANDORA-seq revealed stable sncRNA landscapes with specific dynamic shifts, leading to the identification of seven novel biomarkers (four tsRNAs, three piRNAs) for PMI prediction (R² = 0.760, MAE = 158.990 min). Bacterial-derived sRNAs, predominantly from Staphylococcus aureus, were upregulated at 30 h postmortem, suggesting complementary biomarker potential. Bioinformatics analysis indicated that host miRNAs may target bacterial mRNAs, hinting at cross-kingdom interactions. Conclusion: These findings highlight the potential of integrated endogenous and exogenous sRNA analysis in PMI estimation, providing a high-precision, rapid diagnostic tool and revealing complex postmortem molecular processes. Full article

Urinary tract infections (UTIs) are the most frequent infections in hospitalized and outpatient settings, where Escherichia coli is the predominant pathogen. Conventional diagnostic and antimicrobial susceptibility testing (AST) methods are time-consuming, often requiring 48 h, leading to empirical antibiotic therapy and contributing to antimicrobial resistance (AMR). FASTinov^® developed a rapid phenotypic method that enables AST directly from urine samples within two hours using flow cytometry. In this study, 154 inoculated urine samples were analyzed to evaluate the performance of two diagnostic panels: FASTgramneg for Gram-negative bacteria and FASTgrampos for Gram-positive bacteria. Data analysis was performed using bioFAST^® software (version 3.0), providing results in accordance with EUCAST guidelines. The FASTgramneg panel allows detection of resistance mechanisms, including extended-spectrum β-lactamases (ESBLs), and screening of AmpC β-lactamases and carbapenemases; the FASTgrampos panel additionally determines the minimal inhibitory concentration (MIC) of vancomycin for Staphylococcus aureus. Overall agreement with conventional AST methods was 97.5% for Gram-negative bacteria and 95.0% for Gram-positive bacteria. All resistance mechanisms were correctly identified with no false positives. The essential agreement for vancomycin’s MIC was 95.2%, with a BIAS of +14.3%. Reproducibility was 99.5% for FASTgramneg and 95.0% for FASTgrampos. These results demonstrate that the FASTinov^® kit significantly reduces turnaround time while maintaining high accuracy, supporting improved UTI management and antimicrobial stewardship. Full article

Background/Objectives: Nanostructured biomaterials based on natural polymers have gained increasing attention in pharmaceutics due to their biocompatibility, multifunctionality, and diverse biomedical applications. This novel study aimed to biofabricate chitosan-doped zinc oxide nanocomposites (CS-ZnONCs) using Leucas aspera leaf extract and to evaluate their physicochemical properties and in vitro biomedical performance. Methods: CS-ZnONCs were synthesized using L. aspera leaf extract through a green precipitation approach, and the resulting nanocomposites were characterized by various spectroscopic techniques. The in vitro antioxidant, antibacterial, and anti-inflammatory activities were evaluated, while wound-healing potential was assessed using L929 fibroblast cell migration assays. Results: UV–visible analysis confirmed the formation of CS-ZnONCs, with a characteristic absorption peak at 362 nm, and FTIR spectra indicated the presence of various important functional groups. XRD results demonstrated the crystalline nature of ZnO within the chitosan matrix. Well-dispersed, quasi-spherical nanoparticles with an average size of 44 ± 3.1 nm were identified by HR-TEM, and a positive zeta potential (+9 mV) suggested considerable colloidal stability. CS-ZnONCs showed a high swelling capacity (88 ± 2.75% for 2%) and significant phytocompound release (65.38 ± 2.79% at pH 7.4). The CS-ZnONCs showed significant antioxidant activity (ABTS of 88.19 ± 1.59%), notable antibacterial efficacy against Staphylococcus aureus (18.78 ± 0.98 mm) and Escherichia coli (17.14 ± 0.96 mm), and significant anti-inflammatory activity (82.12 ± 1.47% membrane stabilization). In vitro biocompatibility and wound-healing assays revealed significant cytocompatibility in Vero cells, with 98.75 ± 1.17% cell viability observed, whereas the fibroblast migration assay demonstrated near-complete wound closure (96.55 ± 6.46%). Conclusions: The green-synthesized CS-ZnONCs exhibit favorable physicochemical properties, biocompatibility, and multifunctional biological activities, supporting their potential as a promising sustainable biomaterial nanomedicine for pharmaceutical formulations, wound healing, and regenerative medicine applications. Full article

Chemical investigation of the marine sponge-derived Streptomyces xiamenensis 1310KO-148 afforded six polycyclic tetramate macrolactams (PTMs), including three known compounds (1–3) and three previously undescribed chlorohydrin-containing analogues, chlokamycins B–D (4–6). Their planar structures were elucidated by extensive analysis of 1D and 2D NMR spectra and HR-ESIMS data, while the relative configurations were assigned using NOESY correlations. The absolute configurations were further confirmed by electronic circular dichroism (ECD) calculations. Compounds 3–6 exhibited significant cytotoxic activity against 14 human cancer cell lines (GI₅₀ = 2.68–24.92 μM) and antibacterial activity against Staphylococcus aureus (MIC = 16.00–32.00 μg/mL) and Micrococcus luteus (MIC = 4.00–32.00 μg/mL) among six tested bacterial strains. Full article

Background: The global rise in antimicrobial resistance (AMR) has created an urgent need for innovative antibacterial strategies and localized delivery systems. This study aimed to develop and characterize electrospun poly (vinyl alcohol) (PVA) nanofibers co-loaded with atorvastatin (ATR) and zinc oxide (ZnO) nanoparticles for use as a multifunctional topical platform for wound healing and infection control. Methods: ZnO nanoparticles were prepared via ball milling and characterized for size and zeta potential. Four PVA-based nanofiber formulations were fabricated using electrospinning: blank (F1), ZnO-loaded (F2), ATR-loaded (F3), and ATR/ZnO co-loaded (F4). The nanofibers were evaluated for morphology, thermal properties, crystallinity, and drug release. Antibacterial efficacy was tested against S. aureus, S. epidermidis, MRSA, and P. aeruginosa using broth microdilution and checkerboard assays. Biocompatibility and wound healing potential were assessed via MTT and fibroblast scratch assays on human foreskin fibroblasts (hFFs). Results: SEM imaging confirmed the production of uniform, bead-free nanofibers. ATR and ZnO nanoparticles were successfully incorporated in the nanofiber. The co-loaded formulation (F4) demonstrated a sustained release profile, releasing approximately 78.7% of ATR over 24 h. While all treatments showed limited activity against P. aeruginosa, the ATR/ZnO co-loaded nanofibers exhibited significantly enhanced antibacterial activity against Gram-positive strains, achieving the lowest MIC values (1.5–2.0 mg/mL). Synergy analysis confirmed an enhanced effect with ATR and ZnO against MRSA. Furthermore, F4 achieved the highest wound closure rate of 92.41% in 24 h while maintaining acceptable cytocompatibility. Conclusions: The integration of ATR and ZnO into PVA nanofibers provides an enhanced antibacterial effect consistent with the synergistic potential observed between free agents targeting Gram-positive wound pathogens. The platform’s ability to simultaneously inhibit bacterial growth and promote rapid fibroblast migration positions it as a promising localized therapeutic for managing infected wounds. Full article