Search Results (34,278)

When in contact with microbes or other pathogens plants develop an induced defense response. This reaction is triggered by pathogen-derived molecules that provoke the so-called microbe-associated molecular pattern (MAMP)-triggered immunity (MTI) or pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). Recognition of a MAMP or PAMP by a pattern recognition receptor (PRR) activates rapid downstream signaling, manifested in, e.g., a rise in the cytosolic Ca²⁺ concentration. As a consequence, defense-related genes are expressed and antimicrobial substances are produced. There is also evidence that Ca²⁺-induced responses show a refractory behavior in plant cells, as the reaction to an identical stimulus applied shortly after the first one is strongly suppressed, if it can be observed at all. Subsequent elicitations over a longer period of time, on the other hand, can trigger stronger Ca²⁺ responses, which lead to so-called “defense priming”. Although refractory behavior has been documented in various plant cell types, its underlying function and causative mechanisms remain unclear. In this review article we give an overview of the refractory machinery, including elicitors, receptors, typical Ca²⁺ responses, and signal transduction pathways. We shed light on possible explanatory scenarios and address open questions. Full article

Healthcare-associated infections (HAIs) remain a significant global challenge, affecting approximately 7% of patients in developed countries and over 10% in developing regions, according to the World Health Organization. Medical textiles, particularly hospital bed linens and pillowcases, play a critical role in the transmission of pathogenic microorganisms due to their porous structure and moisture-retaining properties, which support microbial survival and proliferation, including bacteria such as Staphylococcus aureus and Escherichia coli. Conventional disinfection methods, including laundering and thermal treatments, provide only temporary protection, leading to rapid recontamination during use. In recent years, various antimicrobial agents and functionalization techniques have been developed to impart long-lasting antiseptic properties to textile materials. However, these approaches differ significantly in terms of antimicrobial efficiency, durability, cost-effectiveness, and environmental impact, making the selection of optimal strategies challenging for practical healthcare applications. This review provides a comprehensive comparative analysis of antimicrobial agents used in healthcare textile functionalization, including metal-based nanoparticles, organic compounds, and bio-based materials. In addition, it evaluates key modification methods such as coating, padding, and in situ synthesis, with particular emphasis on their influence on antimicrobial performance, wash durability, and practical applicability. Furthermore, this review discusses major challenges associated with the use of antiseptic coatings, including toxicity, environmental concerns, and economic limitations. Based on the analysis, promising directions for the development of safer, cost-effective, and durable antimicrobial textile systems are highlighted, offering valuable insights for future research and real-world healthcare applications. Full article

Urinary Tract Infections (UTIs) represent one of the most prevalent bacterial infections globally, posing significant health burdens, especially in low- and middle-income countries (LMICs), due to delayed diagnoses, limited access to laboratory services, and rising antimicrobial resistance. This study presents a machine learning (ML)-based diagnostic support framework for early UTI detection, leveraging structured clinical data and explainable artificial intelligence (XAI) techniques to enhance interpretability and trust among healthcare providers. A patient dataset containing 4865 records was used in the study to train and test Extreme Gradient Boosting (XGBoost), Decision Tree (DT) and Random Forest (RF) classifiers, while class imbalance was addressed using Synthetic Minority Over-sampling Technique (SMOTE). The performance of the models was evaluated through accuracy, precision, recall, F1-score, Log Loss, and AUC-ROC, and random forest showed the best results (accuracy: 86.43%, F1-score: 86.71%, AUC-ROC: 0.8695). To ensure that such models can be adopted by stakeholders in the health sector, Local Interpret-able Model-agnostic Explanations (LIME) were integrated, which identified painful urination, urinary frequency, and suprapubic pain as primary predictors in the model. This study shows that interpretable ML models can be helpful in resource-limited regions in predicting UTIs, thereby rendering a solution to improve the management of infections in these regions. Full article

This study evaluates fungal-assisted extraction by solid-state fermentation (FAE-SSF) as a green alternative for recovering phenolic compounds from Moringa oleifera leaves and compares it with conventional maceration, focusing on their effects on antimicrobial and antioxidant properties. FAE-SSF was carried out using Aspergillus niger, and phenolic compounds were quantified as total polyphenols (hydrolysable and condensed tannins), followed by purification and characterization by HPLC-ESI-MS. Biological activities were assessed through antibacterial, antifungal, and DPPH assays. FAE-SSF increased total phenolic content to 20.3 ± 1.7 mg TP/g dry basis at 96 h, representing a 1.53-fold increase compared to maceration (13.3 ± 0.3 mg TP/g db at 24 h). However, maceration showed higher productivity due to shorter extraction time. FAE-SSF extracts exhibited improved antibacterial activity against Staphylococcus aureus, while no activity was observed against Shigella sp., and antifungal activity was lower compared to maceration. Antioxidant activity was also reduced in FAE-SSF extracts (39 ± 7%) compared to maceration (71 ± 4%). HPLC-ESI-MS analysis revealed that maceration preserved a greater diversity of phenolic compounds, whereas FAE-SSF induced biotransformation and reduction of key flavonoids. These results indicate that FAE-SSF enhances phenolic recovery but alters chemical composition and bioactivity, highlighting the importance of process optimization depending on the desired functional properties. Full article

Rising antimicrobial resistance has revived global interest in phage therapy, yet its transition to standard clinical practice remains slow. This challenge is not solely due to a lack of efficacy. Instead, we face a fundamental conceptual barrier caused by an “evaluation mismatch.” Traditional regulations treat phages as static chemical molecules—like taking a “snapshot.” However, biologically, phages are dynamic, evolving populations—more like a living “movie.” In this review, we use Schrödinger’s cat metaphor to explain this reality: phage variability is not a defect, but an essential feature. To bridge this gap, we propose a Controlled Evolutionary Platform. By distinguishing between a fixed “Safety Core” and a fluctuating “Adaptive Periphery,” we can manage viral evolution rather than trying to stop it. Ultimately, to integrate phages into modern medicine, we must redefine “consistency”: shifting our focus from preserving a fixed genetic sequence to ensuring the reliable performance of population dynamics. Full article

Magnesium is an essential divalent cation required for adenosine triphosphate (ATP)-dependent reactions, nucleic acid metabolism, and ribosomal stability. Bacteria depend on specialized transport systems to maintain intracellular Mg²⁺ homeostasis as it cannot freely cross the phospholipid bilayer. During infection, host nutritional immunity restricts metal availability, and magnesium limitation within the phagosome compromises bacterial metabolism and stability. This review summarizes the major bacterial magnesium transport systems and their roles in survival and pathogenicity, with an emphasis on Salmonella and extension to clinically relevant ESKAPE pathogens. We focus on the PhoPQ-regulated MgtA, MgtB, and MgtC system, in which low magnesium, acidic pH, and other host-derived signals activate PhoPQ to induce mgt gene expression. MgtA and MgtB act as high-affinity P-type ATPases, whereas MgtC promotes bacterial survival within the intramacrophage environment by inhibiting bacterial F-type ATP synthase through specific interactions with subunit a. We also discuss CorA as a conserved channel for basal Mg²⁺ uptake and MgtE as a Mg²⁺-selective channel whose gating responds to intracellular Mg²⁺ and ATP. Finally, we consider the conservation and variation in these systems across pathogenic bacteria and their potential as therapeutic targets for antimicrobial development. Full article

Thyme (Thymus callieri Borbás ex Velen) and summer savory (Satureja hortensis L.) are aromatic plants from the Lamiaceae family widely used in traditional medicine and the food industry. This study provides a comparative analysis of the phytochemical profiles and biological potential of the essential oils (EOs) of these two plant species from Bulgaria. The chemical composition was determined using GC-MS analysis. Biological evaluation included determination of antioxidant activity (DPPH assay), antimicrobial activity (MIC assay), ex vivo anti-inflammatory effects (IL-1β expression in rat stomach smooth muscle preparations), and in vitro antihemolytic activity. GC-MS analysis identified 16 compounds in T. callieri EO, dominated by p-cymene (46.42%) and thymol (35.80%). In contrast, 17 compounds were identified in S. hortensis EO, with carvacrol (58.81%) and γ-terpinene (22.46%) as major constituents. Both EOs exhibited concentration-dependent antioxidant activity, with S. hortensis showing higher radical scavenging potential. In antimicrobial tests, both oils demonstrated broad-spectrum efficacy with MIC values ranging from 0.313 to 2.5 mg/mL. Ex vivo experiments revealed that T. callieri EO significantly increased IL-1β expression, suggesting immune activation, while S. hortensis EO showed a lower effect, indicating higher anti-inflammatory potential. Furthermore, S. hortensis EO demonstrated superior erythrocyte membrane stabilization (antihemolytic activity) compared to T. callieri EO and the reference anti-inflammatory drug Aspirin. In conclusion, the findings highlighted the distinct biological potential of both Bulgarian EOs, suggesting their diverse applicability as natural bioactive agents in the pharmaceutical and food industries. Full article

Hidradenitis suppurativa (HS) is a chronic inflammatory dermatosis characterized by recurrent nodules, abscesses, and sinus tract formation in intertriginous skin. Although HS is increasingly recognized as an autoinflammatory condition rather than a classical infection, antimicrobial therapies remain central to disease management, implicating a potential role for the cutaneous microbiome in disease activity. Recent advances in culture-independent sequencing techniques have enabled more detailed characterization of microbial communities in HS, revealing consistent alterations in microbial composition and diversity. Compared with healthy skin, HS lesions exhibit reduced microbial diversity, depletion of commensal organisms such as Cutibacterium acnes, and enrichment of anaerobic bacteria including Prevotella, Porphyromonas, and Finegoldia. These alterations are more pronounced in chronic, tunnel-forming disease and are frequently associated with biofilm formation, which may contribute to treatment resistance and persistent inflammation. Microbiome changes have also been observed beyond overtly lesional skin, suggesting a broader field effect. Evidence regarding extracutaneous microbial compartments, particularly the gut microbiome, remains limited and heterogeneous, while methodological variability in sampling, sequencing, and treatment exposure continues to complicate cross-study comparisons. Emerging data further suggest that immune-targeted therapies, including biologic and small-molecule agents, may indirectly influence microbial community structure through modulation of the inflammatory milieu. Collectively, the available evidence supports cutaneous dysbiosis as a characteristic feature of HS that may potentially interact bidirectionally with immune dysfunction. Future longitudinal, multi-omic studies integrated with clinical phenotyping will be critical to clarify causal relationships and to determine whether microbiome modulation can be leveraged to improve therapeutic outcomes in HS. Full article

Extracellular traps (ETs) are immune-derived chromatin networks initially described as antimicrobial barriers but increasingly recognized as modulators of tissue homeostasis and autoimmunity. The oral mucosa, constantly exposed to inflammatory stimuli, is particularly sensitive to ET-mediated remodeling (extracellular traps-mediated remodeling). In this study, we investigated how platelet-rich plasma (PRP), platelet-poor plasma (PPP), and washed platelets (WPT), widely used in regenerative medicine, influence ETosis in monocytes and macrophages, and how these ETs modulate the responses of primary buccal keratinocytes (pBMKs). ETs were induced in monocytes/macrophages using PRP, PPP, and WPT. pBMKs were exposed to ET-rich supernatants, and proliferation was monitored in real time through a live cell imaging system. ETs derived from PRP, PPP, and WPT did not induce either a statistically significant proliferation or morphological changes in buccal keratinocytes. These findings suggest that both platelet-derived products (PRP, PPP, WPT) and ETs play a crucial role in modulating epithelial biology, thus suggesting their possible role in chronic autoimmune diseases characterized by persistent inflammation and epithelial remodeling. Full article

We evaluated the antimicrobial and antioxidant capabilities of a bacteriocin purified from a recently identified marine Lactococcus lactis (L. lactis) NAN6399 strain, a lactic acid bacterium recovered from Mediterranean coastal waters near Alexandria, Egypt, and identified by combined API 50 CHL phenotypic profiling and 16S rRNA gene sequencing. Bacteriocin purification was achieved by sequential ammonium sulfate precipitation and reverse-phase high-performance liquid chromatography (RP-HPLC). The purified bioactive fraction had an approximate molecular weight of 20 kDa by SDS-PAGE and a 106-amino-acid N-terminal sequence that, upon BLAST alignment, returned 98.1% overall identity to the Lactococcin 972 family bacteriocin AAK06118.1 from L. lactis IL1403, with divergence confined exclusively to the terminal two C-terminal residues. This sequence is structurally and functionally distinct from canonical Lcn972 (L. lactis IPLA 972): the two peptides share an identical 25-residue signal peptide but diverge entirely in their mature bioactive domains, which exhibit only 9.1% sequence identity. Canonical Lcn972 operates through Lipid II-mediated septum disruption and inhibits only Lactococcus species; the NAN6399 peptide, correctly designated as a novel member of the Lcn972-like peptide family, demonstrated broad-spectrum antimicrobial efficacy against multiple indicator organisms (Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis), producing inhibition zones of up to 30 mm and minimum inhibitory concentration (MIC) values as low as 1.25 μg/mL against S. aureus. Antioxidant capacity was assessed using the DPPH radical scavenging assay, with the purified preparation achieving 73.14 ± 0.34% inhibition. Collectively, these data establish L. lactis NAN6399 as the producer of a bifunctional Lcn972-family bacteriocin with both antimicrobial and antioxidant potential, provide the first experimental characterization of the antimicrobial activity of this Lcn972-family branch, and highlight marine LAB as a productive reservoir for novel bioactive peptide discovery. Full article

This study aimed to investigate the wound-healing mechanisms of chitosan with a defined molecular weight (MW) and degree of deacetylation (DD), and to explore its potential in hydrogel formulations, optimized for enhanced antibacterial performance. An active molecular chitosan (AMC) was prepared via enzymatic treatment to target a specific MW range with excellent biological activity. The antibacterial, anti-inflammatory, and wound-healing effects of AMC-based hydrogels were evaluated. Given AMC’s antibacterial activity against vancomycin-resistant Staphylococcus aureus (VRSA), its anti-inflammatory effects were also evaluated in full-thickness wounds in BALB/c nude mice. Anti-inflammatory effects were assessed using ELISA and immunohistochemical staining to measure levels of IL-1β, IL-4, IL-6, IL-10, and TNF-α. AMC treatment significantly reduced wound size and suppressed inflammatory cytokine production. These results suggest that hydrogels containing AMC may enhance both antibacterial and anti-inflammatory properties, potentially promoting wound healing. Full article

Sparassis crispa (cauliflower mushroom) is an edible medicinal fungus known for its diverse array of bioactive metabolites. Despite its established nutritional and pharmacological relevance, its antimicrobial, antiviral, and antiparasitic activities remain insufficiently investigated. In the present study, extracts of the fruiting bodies of S. crispa were prepared using four solvents (water, 60% ethanol, methanol–acetone–water [3:1:1], and 1% acetic acid) and evaluated for their chemical composition and broad-spectrum biological activities. UHPLC-MS/MS profiling revealed distinct metabolite profiles among the extracts, including identification of nucleosides such as adenosine and methylthioadenosine. All extracts exhibited nematicidal activity against Rhabditis sp. nematodes in a dose-dependent manner, with the 60% ethanol extract being the most potent (LD₅₀ = 4.2 mg/mL). In antiviral assays, the water extract partially inhibited Coxsackievirus B3 (CVB3) replication, reducing infectious titers by approximately 2 log units, whereas none of the extracts showed a significant effect against Herpes simplex virus type 1 (HSV-1). Antibacterial testing demonstrated activity only for the 1% acetic acid extract, which inhibited several Gram-positive and Gram-negative bacteria at minimum inhibitory concentrations of 10–20 mg/mL. No antifungal activity against Candida spp. was observed. These findings identify Sparassis crispa as a promising edible source of bioactive compounds, exhibiting pronounced nematicidal and moderate antimicrobial activities, and support its potential application in the development of functional foods and nutraceuticals. They further justify targeted isolation and mechanistic studies to characterize the metabolites responsible for these effects and to clarify their relevance for food-based health promotion. Full article

Dental implants are widely used to replace missing teeth, but peri-implantitis remains a major biological complication associated with bacterial biofilm formation on implant surfaces. The increasing incidence of peri-implant infections underscores the need for alternative antimicrobial strategies that effectively decontaminate complex titanium implant surfaces. This study evaluated the inhibitory effect of low-temperature microwave argon plasma on bacteria in an experimental model simulating peri-implant conditions and compared the responses of microorganisms with different biological characteristics. A 3D-printed mandibular bone segment model with an inserted Straumann BLX Roxolid^® dental implant was used to reproduce the peri-implant environment. Bacterial suspensions of Streptococcus mutans NBIMCC 1786 and the extremophilic bacterium Chromohalobacter canadensis NBIMCC 9077 have been exposed to a microwave non-equilibrium argon plasma jet (2.45 GHz, atmospheric pressure) for 1–7 min. Optical density measurements and colony growth analysis were used to assess antimicrobial effects. Plasma treatment induced a pronounced reduction in bacterial growth during the early post-treatment period. In C. canadensis, growth inhibition reached a plateau (~47–55% at 24 h) regardless of exposure time. In contrast, S. mutans showed a nonlinear response, with stable inhibition after short exposures (1–3 min) and partial recovery after longer treatments (5–7 min). These findings indicate that microwave argon plasma exhibits significant antimicrobial activity under controlled in vitro conditions, although its effectiveness depends on microorganism-specific biological characteristics. Because the present model was based on simplified single-species systems, direct clinical extrapolation remains limited and should be addressed in future studies using polymicrobial peri-implant biofilm models. Full article

Antimicrobial resistance (AMR) has become a major concern in the treatment of bacterial infections, and bacteriophage therapy has emerged as a promising alternative to antibiotics. Bacteriophages are highly specific to their bacterial hosts; hence, isolating phages indigenous to a specific region offers a significant advantage against various pathogen strains. We have isolated a cocktail of bacteriophages against pathogenic E. coli from sewage water at a primary healthcare centre. Characterisation of the isolated phages demonstrated their stability across a broad pH and temperature range, strong lytic activity, and effective biofilm degradation, with no cross-reactivity with Staphylococcus aureus (S. aureus). Genomic analysis and phylogenetic studies indicated that the largest phage (by genome size) in the cocktail belongs to the genus Vequintavirus (myoviruses, rV5-like phages), and its genome sequence has been deposited in NCBI (Accession ID: PX741096). The phage genome was linear, with headful (PAC) packaging, encoded lysis proteins, and lacked antibiotic-resistant or major lysogeny-associated genes, collectively suggesting a lytic lifestyle. These findings emphasize the therapeutic potential of rV5-like phages and underscore the critical need to establish phage banks in India to improve disease management. Full article

Background: Phospholipids are essential components of bacterial membranes and play central roles in membrane integrity and adaptation to antibiotic stress. However, confident annotation of phospholipid molecular species remains challenging due to the complexity of the lipidome and the limited structural constraints in conventional lipidomics workflows. Methods: Here, we present a bacterial phospholipidomic framework that integrates orthogonal structural evidence to achieve high-confidence and traceable annotation. Thin-layer chromatography (TLC) provides phospholipid headgroup assignment, gas chromatography–mass spectrometry (GC–MS) defines the acyl-chain pool, and Paternò–Büchi derivatization enables C=C localization, collectively restricting the structural search space prior to liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis. A rule-based ion prediction library further standardizes diagnostic ion assignment and reduces annotation ambiguity. Results: Applying this platform, we found Escherichia coli in the stationary phase remodeled the membrane phospholipids, with cardiolipin (CL) increasing from ~5% to ~10% and cyclopropane-containing phospholipid species rising to ~75%. Similar remodeling patterns are observed under diverse antibiotic exposures at sub-inhibitory concentrations, consistent with convergence toward a tolerance-associated membrane state. Extension of the framework to Enterococcus faecium supports proof-of-concept application in an additional Gram-positive model, with vancomycin-resistant strains exhibiting pronounced phosphatidylglycerol (PG) enrichment and reduced CL. Conclusions: Our work provides a scalable and reproducible strategy for bacterial phospholipid annotation, enabling molecular-species-resolved investigation of membrane adaptation and offering a framework for future exploration of lipid homeostasis pathways as potential antimicrobial targets. Full article