Search Results (34,288)

Background: Acinetobacter baumannii is a non-fermenting Gram-negative bacillus responsible for severe nosocomial infections, particularly in intensive care units (ICUs). The increasing prevalence of multidrug-resistant (MDR) and carbapenem-resistant A. baumannii (CRAB) strains has become a significant challenge for infection control and antimicrobial therapy worldwide. Objectives: This study aimed to analyze the antimicrobial susceptibility patterns of clinical A. baumannii isolates recovered from a multi-profile hospital in years 2020–2024 in Lodz, Poland. Methods: Clinical isolates from various specimen types (blood, urine, wound swabs, biopsies, sputum, and bronchoalveolar lavage fluid) were obtained during routine microbiological diagnostics. Identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was conducted using the automated VITEK^®2 system with EUCAST/CLSI interpretive criteria. Minimum inhibitory concentrations (MICs) for colistin were determined by broth microdilution. Carbapenemase production was assessed using the Carbapenem Inactivation Method (CIM) and immunochromatographic assays for OXA-23, OXA-40/58, and NDM detection. Results: A total of 244 A. baumannii isolates were recovered over the study period. Susceptibility to carbapenems (meropenem, imipenem) declined markedly, with resistance exceeding 90% by 2023–2024. Aminoglycosides exhibited variable activity, with gentamicin demonstrating the highest susceptibility rates (up to 88% in 2022). Resistance to ceftazidime and cefepime remained consistently high (>90% in 2023–2024). No fully susceptible isolates were identified for ciprofloxacin. Conclusions: The high prevalence of CRAB strains highlights the urgent need for effective infection control measures, optimized antimicrobial stewardship, and consideration of novel treatment options in the clinical setting. Full article

This study presents an exploratory reinforcement learning (RL)-based simulation framework for examining antimicrobial resistance (AMR) dynamics under repeated exposure to a non-antibiotic stressor, using copper as a simplified model compound. The objective is not to provide mechanistic or predictive insight into microbial evolution, but to evaluate how alternative sequential decision-making strategies perform within a constrained and transparent simulation environment. Three agent strategies were compared: random action selection, a rule-based heuristic, and a tabular Q-learning agent. Simulations were conducted over fixed 40-cycle episodes in which agents adjusted copper exposure in response to evolving resistance-related state variables. Across experimental runs, the Q-learning agent exhibited lower cumulative resistance burden, measured by area under the curve (AUC) of minimum inhibitory concentration (MIC) trajectories for chloramphenicol and polymyxin B, while maintaining lower cumulative copper exposure relative to baseline strategies. The rule-based agent demonstrated intermediate performance, whereas the random agent showed greater variability and less stable trajectories. These findings reflect differences in simulated control behavior within a simplified stochastic system. Overall, this work introduces an interpretable reinforcement learning simulation tool intended to support comparative evaluation of adaptive versus static strategies in antimicrobial pressure management under limited observability. Full article

Microorganisms can aggregate and organise into structured communities embedded within an exopolysaccharide-based matrsix, which serves as a protective barrier and a functional environment around microbial cells. The formation of biofilms is widely recognised as a pivotal factor in bacterial virulence, impeding the efficacy of antimicrobial agents and hindering immune responses, whilst concomitantly contributing to the development of antimicrobial resistance and the onset of persistent infections. Biofilm formation is a tightly regulated and dynamic process, controlled by quorum-sensing mechanisms and profoundly influenced by environmental factors and nutrient availability. The objective of this review is to elucidate the significance of biofilms in clinical settings, with a particular focus on their role in the pathogenesis of infectious diseases. Particular attention is devoted to biofilm-associated infections and infections related to invasive medical devices, with a particular emphasis on the most prevalent microbial pathogens, which include S. aureus, S. epidermidis, P. aeruginosa, E. coli, K. pneumoniae, A. baumannii and various species of Candida. Furthermore, the present review encompasses biofilm-associated chronic infections, conditions manifesting in predisposed patients, including individuals affected by cystic fibrosis. This review further examines the most recent strategies for combating antibiotic resistance in bacterial biofilms. This review focuses on recent biofilm pathogenesis advancements, with a focus on diagnosis challenges and the need for new ways to disrupt biofilm integrity. Full article

Background/Objectives: Silver’s ability to kill pathogenic bacteria is being widely researched in environment, consumer, and health-related applications. One topic of voluminous research is the antimicrobial properties of silver and silver in wound dressings. This research literature has been reviewed in articles using qualitative analyses, meta-analyses, systematic reviews, bibliometric analyses, and other grounded methods. We present a new strategy for the analysis of the population of articles on the subject based on an ontology of this topic. Methods: A search of the Scopus database for all peer-reviewed articles on silver in wound dressings yielded a population of 4711 relevant ones. The ontology is a logical deconstruction of the problem: “use of silver species on nanosupports deposited on a matrix with antimicrobial effectiveness assayed by methods to promote wound healing of chronic wounds as determined by recovery”. Each bolded term denotes a dimension of the ontology, and each dimension denotes a taxonomy of constituent elements. A Convolutional Neural Network (CNN) was trained using a manually mapped subset of articles. The CNN was then used to map the population of articles. Results: Out of the 4711 articles, 3079 dealt with silver and wound dressings; the others involved silver, but were not related to wound dressings and were not considered. Overall analysis shows that three classes of silver encompass the entire field: silver nanoparticles (AgNP) (78% of papers), inorganic silver-ion-containing species (7%) and silver associated with organic molecules (15%). AgNP papers have grown exponentially beginning in the early 2000s; there is no clear trend regarding inorganic silver-containing-species papers; whereas with the silver-organics species papers, there has been growth in the past decades, but now the number of publications is stabilizing. Research on the AgNPs has primarily focused on in vitro testing (54%), with very limited animal testing (17%) and human testing (3%). On the other hand, with silver-organics, animal (30%) and human testing (38%) are prominent. Inorganic silver ion species also have been human-tested extensively (43%). Thus, in clinical applications of silver wound dressings, AgNP lags considerably as compared to the other silver species, though academic research in AgNP is robust. Conclusions: From detailed temporal visualizations of the ontological mapping, the antecedents and consequences of silver in wound dressings are presented. This first ontological analysis is a novel way of visualizing an entire research field and the temporal characteristics of the various dimensions of the ontology provide information on the current state of research as well as where the field is headed. Full article

Mesenchymal stromal cells (MSCs) have shown immunomodulatory effects and great promise in many inflammatory diseases such as acute respiratory distress syndrome (ARDS). However, several barriers to translation remain such as cell availability and potency. This study evaluates the therapeutic potentials of three types of MSCs, bone marrow-derived MSCs (BM-MSC), the human induced pluripotent stem cell-derived MSC wild type (iMSC WT) and β2 microglobulin-knockout iMSCs (iMSC B2M KO) with or without proinflammatory cytokine preconditioning. BM-MSC, iMSC WT and iMSC B2M KO were preconditioned with a proinflammatory cytokine cocktail (Cytomix: IL-1β, IFN-γ and TNF-α). Immunoregulatory biomarkers were analysed by flow cytometry and cytokines released by ELISA. MSC antimicrobial properties were analysed via CFU assays while the MSCs’ immunomodulatory effects were evaluated using macrophage activation and T cell proliferation assays. Proinflammatory cytokine preconditioning enhanced the therapeutic potency of all three types of MSCs by increasing immunomodulatory marker expression, enhancing the antimicrobial effects and improving MSC-mediated inhibition of T cell proliferation. These findings provided new insights into the therapeutic potencies of MSCs in inflammation. Further studies are required for in vitro characterisation of the MSCs and in vivo efficacy verification of these MSCs prior to their clinical application. Full article

Introduction: Type 2 diabetes mellitus predisposes patients to neuropathy, peripheral arterial disease, and diabetic foot ulcers, which may become infected and progress to osteomyelitis, increasing the risk of amputation. The growing prevalence of multidrug-resistant organisms complicates management. Photodynamic therapy (PDT), which combines a photosensitizer with light-emitting diode irradiation to generate reactive oxygen species, has emerged as a potential adjunctive antimicrobial strategy without inducing resistance. Objective: To describe clinical outcomes observed in patients with diabetic foot osteomyelitis treated with adjunctive photodynamic therapy (PDT), with emphasis on wound evolution, limb preservation, and healing time. Methods: This prospective case series included patients with osteomyelitis secondary to infected diabetic foot ulcers treated at a university hospital. Demographic and clinical data were collected from medical records. Serial photographic documentation was used to monitor wound progression and tissue response during therapy. Results: Sixteen patients with diabetic foot osteomyelitis were included. Complete healing was achieved in 13 patients (81.25%), while 2 patients (12.5%) remained under treatment with partial healing and 1 (6.25%) underwent major amputation. Among healed patients, healing time ranged from 19 to 546 days, with a median of 118 days. The number of photodynamic therapy sessions ranged from 2 to 12, depending on the clinical course of each case. Healing time varied among patients, and the hallux was the most frequent site of osteomyelitis. During follow-up, only one patient underwent major amputation, whereas the remaining patients either achieved complete healing or were still under treatment at the time of analysis. Healing time was comparable between insulin-dependent and non-insulin-dependent diabetes, although numerically shorter in the latter. Longer healing periods were associated with more treatment sessions. Conclusions: In this prospective uncontrolled case series, adjunctive PDT was associated with favorable clinical evolution in a subset of patients with diabetic foot osteomyelitis. However, because of the small sample size and the absence of a control group, these findings should be considered preliminary and hypothesis-generating. Full article

Zinc oxide promotes poultry growth, but it tends to agglomerate. This necessitates high doses and leads to environmental contamination from unabsorbed, excreted zinc. Undigested zinc is excreted and can enter the food chain, increasing the probability of zinc residues in edible poultry tissues (muscle, liver, and eggs) and raising concerns for consumer safety. MOF-supported single-atom zinc catalysts (SAC) resolve agglomeration by atomic anchoring, enhancing bioavailability. High-temperature/high-pressure fixation of Zn²⁺ surfaces was confirmed by XRD, while FESEM revealed the corresponding surface morphology, collectively verifying SAC formation. SAC exhibited potent antimicrobial efficacy against key pathogens such as Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus (MIC of 3.125 mg/mL, MBC of 25 mg/mL). Co-culture experiments further demonstrated that the antibacterial performance of SAC remained stable over a temperature range of 20–80 °C and a pH range of 2–8, thus exhibiting excellent thermal stability and gastrointestinal tolerance. In 7-day-old chicks, SAC alleviated S. typhimurium-induced inflammation, reduced bacterial adherence, upregulated claudin-1, preserved gut homeostasis, ameliorated tissue lesions, and increased the abundance of Lactobacillus in the cecum, demonstrating promising potential for poultry infection control. Full article

Background/Objectives: The prevalence of resistant pathogens in livestock and the environment threatens human health. Frequently used antibiotics in livestock gradually increase the resistance pattern, which intimately threatens the livestock industry. Methods: About 536 pathological samples were collected from January 2023 to December 2024 from chicken (472), birds (2), goat (25), sheep (12), and cows (21) and buffaloes (4), across the Sindh, Pakistan. A wide variety and number of bacterial pathogens were isolated and identified. After performing their antibiogram study, phylogenetic analysis was also performed. Results: The prevalence of different bacterial infections was studied in livestock. Salmonella spp. was found to be the most common cause of bacterial infection in livestock (77.79%), followed by Escherichia coli (62.69%) and Staphylococcus aureus (8.02%). The highest number of Salmonella spp. and S. aureus isolates were found to be resistant to ampicillin (80.67% and 81.4%, respectively), while E. coli isolates were found to be resistant to amoxicillin (97.87%) majorly. MARI revealed that 79.7% of Salmonella spp., including all MDR strains (n = 332); 55.59% of E. coli (n = 336), and 88.37% of S. aureus (n = 43) had indexes greater than 0.2. 16S bacterial identification and phylogenic analysis were performed through molecular methods. Conclusions: AMR is one of the most considerable livestock health issues that also affect human health. The MARI indicate a high rate of antibiotic use and resistance in the isolated Salmonella, E. coli, and S. aureus require the urgent need for continuous antimicrobial susceptibility surveillance and control of antibiotic use in livestock. Full article

The essential oil (EO) of Sideritis L. has attracted great interest due to its pharmacological activities. At the same time, there is significant variability within the type, related, among other things, to the origin of the raw material. The aim of this work was to study the EO chemical composition of Sideritis scardica Griseb. from Bulgaria and Türkiye. The plant material (air-dried above-ground parts) was purchased from herbal and medical stores in Lublin, Poland. The crushed raw material was used for distillation of the EO. Distillation was performed in a Clevenger apparatus. The EO content was expressed in ml per 100 g of air-dried herb. Analysis of the qualitative and quantitative composition of the obtained EO was performed using gas chromatography coupled with a mass spectrometer (450-GC + 240-MS). The antimicrobial activity of the S. scardica EO was evaluated using the broth microdilution method in accordance with the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. We have demonstrated that the chemical composition and biological activity of sideritis EO depend on the origin of the raw material. Our results indicate that S. scardica EO can be considered a promising antimicrobial agent. Full article

The growing interest in clean-label and naturally preserved foods has pushed the scientific community to research essential oils (EOs) as sustainable, multifunctional alternatives to chemical preservatives. These plant volatile compounds exhibit strong antimicrobial and antioxidant activities, making them promising ingredients for natural preservation. Fermented meat products, though highly nutritional, are particularly at risk of microbial spoilage and contamination by foodborne pathogens due to their complex microbiota and processing conditions. This review examines the role of EOs as natural antimicrobials in fermented meat systems, summarizing their mechanisms of action, efficiency against key pathogens, and impact on safety, shelf life, and sensory attributes. Additionally, it discusses technological challenges related to volatility, stability, and sensory alterations, and outlines mitigation strategies such as encapsulation, nanoemulsions, and controlled-release delivery systems. By critically presenting current progress and identifying research gaps such as standardization and matrix interactions, this review contributes to the development of effective, natural, and clean-label preservation strategies. These insights support innovation and sustainability in the meat processing industry by bridging the gap between antimicrobial efficacy and sensory acceptability. Full article

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