Search Results (7,320)

The rapid emergence of multi-drug resistant (MDR) bacteria has become a major health concern, driving the need to identify new antimicrobial resources. Recently, endophytes, inhabiting in internal tissues of medicinal plants, have drew important interest from the scientific community, as reservoirs of bioactive metabolites. Numerous studies highlight the symbiotic relationship between plants and their endophytes, in which these microorganisms produce antimicrobial compounds, helping the host plant’s defense against pathogens. Plantago major (commonly known as plantain) is widely recognized for its therapeutic properties, especially for its antimicrobial properties. In this study, endophytic fungi were isolated from Plantago major, morphologically characterized and identified using ITS sequencing. Their antibacterial activity was assessed using the agar diffusion assay. In total, 21 endophytic fungal isolates were obtained from different plant tissues, including leaves, stems, roots, and flowers. Antibacterial assays against methicillin-resistant Staphylococcus aureus (MRSA) were investigated on PDA, SDA, and CDA media. Amongst the isolates, nine strains (MD-H1, MD-L1, MD-L2, MD-L3, MD-L4, MD-L5, MD-R1, MD-T1, MD-T2, and MD-T10) showed medium to strong antibacterial effects, with inhibition zones exceeding 15 mm. The result suggests that endophytic fungi associated with Plantago is a valuable source of anti-MRSA compounds. Further work will focus on identifying the secondary metabolites responsible for this activity and elucidating their chemical structures, providing a basis for the development of new potent antibiotic agents. Full article

Neonatal infections remain a leading cause of morbidity and mortality worldwide, particularly among preterm and low-birth-weight infants and in low- and middle-income countries. This burden has intensified with the global increase in multidrug-resistant (MDR) bacteria, especially in neonatal intensive care units, where prolonged hospitalization, invasive interventions, and exposure to broad-spectrum antibiotics promote colonization, transmission, and invasive infection. In this narrative review, we explore the epidemiology and microbiological characteristics of MDR bacterial infections in newborns, alongside their associated risk factors, diagnostic challenges, treatment outcomes, and prevention strategies. Across different settings, Gram-negative pathogens, particularly Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii, account for a substantial proportion of severe neonatal infections, whereas methicillin-resistant Staphylococcus aureus remains important in selected units. The risk of MDR infection is driven by a complex interplay of factors, ranging from maternal and perinatal exposures to the inherent immunological vulnerability of newborns, hospital-based transmission, antibiotic selection pressure, and structural deficiencies in healthcare infrastructure. Diagnosis remains challenging because clinical presentations are nonspecific and culture-based methods are constrained by low blood volumes, prior antimicrobial exposure, and delayed turnaround times. Treatment is increasingly complicated due to resistance to standard empirical regimens, substantial regional variation in susceptibility profiles, and limited neonatal pharmacokinetic and safety data for reserve agents. Current evidence mainly supports surveillance-informed empirical therapy, susceptibility-guided treatment adjustment, antimicrobial stewardship, and strict infection prevention measures. Future progress will require neonatal-specific clinical trials, harmonized surveillance systems, stronger molecular epidemiology, and more equitable access to microbiological diagnostics and effective treatment. Full article

The present work aimed to obtain antibacterial wound dressings using bacterial cellulose (BC) as a support, to improve wound treatment and reduce the incidence of infections. To enhance the antibacterial activity of the synthesized dressings, the introduction of ZnO nanoparticles into the BC network by precipitation was pursued. The method chosen to develop ZnO NPs was green synthesis, an ecological and sustainable method for obtaining nanomaterials using plant extracts as reducing agents or stabilizers. Thus, the chosen plants were Ginger rhizomes, Bay leaves, and Rose hips, in both fresh and dry form, due to the natural benefits they possess, and the Soxhlet method was used to obtain the plant extracts desired to be used in the synthesis. The composite dressings were developed in two distinct sample series, differentiated by the immersion time of BC in the precursor Zn²⁺ solution. The samples in the first series were obtained by precipitation in a mixture of Zn²⁺ solution and natural extract, whereas the samples in the second series were obtained by successive immersion in Zn²⁺ solution and then in natural extract, which demonstrated a considerable difference. The best antimicrobial activity tested against Gram-negative bacterium Escherichia coli was recorded for the composite material obtained in the presence of fresh rose hip extract, an aspect most likely related to the morphological and crystalline features of the ZnO phase, but also to the phytochemical profile of the extract used. Such eco-friendly materials represent valuable candidates for wound dressing applications due to their ability to support wound healing, relief burns, and skin irritation, provide antimicrobial protection, promote skin regeneration and reduce scarring, protect sensitive skin, and act as a barrier against external contaminants. Full article

The skin represents the largest organ in the body and functions to protect internal tissues from damage and infection. When wounds in small animals do not receive proper management, they may progress to chronic conditions, resulting in pain, delayed healing, and impaired well-being. Although conventional treatment mainly includes the use of topical antimicrobial agents and anti-inflammatory drugs, integrative veterinary medicine has been considered a promising complementary approach to enhance tissue repair. In this context, this study aimed to review non-conventional therapies applied to wound management in small animals, focusing on ozone therapy, light therapy that stimulates cellular activity, herbal medicine, and apitherapy, especially propolis. Overall, the analyzed studies indicate that ozone may contribute to microbial control and modulation of the immune response; light therapy may stimulate cellular activity and collagen production, promoting healing; medicinal plants present antioxidant and anti-inflammatory effects; and propolis demonstrates antimicrobial and regenerative properties. Thus, when responsibly applied and supported by scientific evidence, these approaches may complement conventional therapy, broaden clinical possibilities, and contribute to improved recovery and quality of life in animals. Full article

The field of nanoparticle-based biotechnology has undergone substantial advancement, characterized by progress in targeted drug delivery systems, the development of innovative diagnostic and imaging platforms, the expanded adoption of environmentally sustainable (“green”) synthesis approaches, and an increasing emphasis on the integration of emerging technologies such as artificial intelligence and nanorobotics. Conventional nanoparticle synthesis often involves toxic reducing agents; however, recent advances promote eco-friendly green synthesis methods utilizing biological systems such as bacteria, fungi, algae, yeast, plants, and actinomycetes. These biological approaches are safe, sustainable, cost-effective, and capable of producing highly stable Nanoparticles (NPs). The interaction of nanomaterials with biological systems is crucial for developing intracellular and subcellular drug delivery technologies with minimal toxicity, governed by nano–bio interface mechanisms such as cellular translocation, surface wrapping, embedding, and internal attachment. Key factors influencing NP behavior include morphology, size, surface area, surface charge, and ligand chemistry. Magnetic nanoparticles, particularly iron-based forms, exhibit unique superparamagnetic properties that are strongly influenced by particle size, as explained by the Néel relaxation mechanism, in which thermal energy induces flipping of magnetic moments. Nanoparticles demonstrate diverse modes of action, including antimicrobial activity, reactive oxygen species (ROS)-induced cytotoxicity, genotoxicity, and plant growth promotion. NP performance and biological effects are strongly dependent on their size, shape, dosage, and concentration. This critical review article aims to elucidate evolution, classification, preparation methods, and multifaceted applications of nanoparticles Full article

Hesperidin, a flavonoid abundantly found in citrus fruits, has demonstrated a substantial role in the management of various pathogeneses. Furthermore, the wide range of health-promoting properties of hesperidin, including antioxidant, anti-inflammatory, anti-cancerous, hepatoprotective, neuroprotective, nephroprotective, and cardioprotective effects, has been well documented. Additionally, persuasive evidence from both in vivo and in vitro studies highlights its substantial roles in combating obesity, protecting the kidneys, liver, and lung tissue architecture, promoting wound healing, and modulating immune responses. This flavonoid acts as an effective antimicrobial agent against a wide range of microorganisms by inhibiting biofilm formation and disrupting the cell membrane. This review aims to deliver comprehensive insights into the therapeutic potential of hesperidin across different pathogenesis through distinct mechanisms. Moreover, it provides up-to-date evidence on the synergistic properties of this compound with other drugs as well as compounds, and emerging plans to enhance its efficiency in health management through various nanoformulation approaches. Despite its considerable therapeutic potential, the clinical application of hesperidin remains constrained by poor bioavailability, rapid degradation, and dosage-related limitations. Addressing these challenges will require extensive further research to clarify its mechanisms of action, safety profile, and therapeutic efficacy in managing underlying pathogenic conditions. Full article

Background and Objectives: The epidemiological characteristics of Candida species have changed worldwide, with an increasing number of reports on co-infections with non-albicans Candida species (NACs) and multidrug-resistant bacteria. A longer length of hospital stay, more severely ill patients, and empirical antimicrobial use in intensive care units (ICUs) increased the prevalence of Candida healthcare-associated infections (HAIs). If the diagnosis or treatment of invasive candidiasis is delayed, the morbidity and mortality of patients will significantly increase. Materials and Methods: We conducted a nationwide surveillance study to analyze data on HAIs in the ICUs of medical centers and regional hospitals between 2018 and 2023. We assessed the temporal trends of Candida species (including Candida albicans and NACs) across all HAIs, bloodstream infections (BSIs), and urinary tract infections (UTIs), and simultaneously assessed the corresponding trends of Enterococcus faecium (Efm). A linear trend for the proportions of microorganisms from 2018 to 2023 was noted according to the Mantel–Haenszel chi-square test. Spearman’s rank correlation coefficients were used to analyze the correlations between pathogen proportions, systemic antimicrobial agent consumption, and length of ICU stay. Results: The overall proportion of all Candida species in HAIs in the ICUs increased significantly from 15.13% to 16.74% (p < 0.001); this increase was driven mainly by NACs (increasing from 6.84% to 7.91%, p < 0.001) from 2018 to 2023. The proportion of Efm increased significantly, from 7.7% to 11.11% (p < 0.001). The proportions of all Candida species significantly increased in UTIs (from 24.63% to 28.13%, p < 0.001), especially NACs, while the proportion of Efm also increased significantly in UTIs (from 9.47% to 15.32%, p < 0.001). With respect to the UTIs, the proportion of all the Candida species, C.albicans, and NACs were positively correlated with the amount of systemic antibiotics used. A longer hospital stay was strongly correlated with all Candida HAIs and UTIs, especially NACs. Significantly ecological associations between all the Candida strains and Efm were observed for UTIs. Conclusions: This study revealed that a persistent expansion of NAC infections was associated with increased Efm infections and rising antibiotic consumption. The changes in the proportions of different Candida species in UTIs were most pronounced. These findings support an ecological model in which antibiotic stress and chronic critical illness contribute to the expansion of fungal–bacterial co-infections in the ICU setting and underscore the need for integrated antibiotic management and multi-infection surveillance. Full article

The Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET-ATRP) of vanillin methacrylate (VMA), a bio-based methacrylic monomer derived from vanillin, was systematically studied for the first time. The reaction conditions were optimized aiming at achieving good monomer conversions while preserving the antimicrobial aldehyde functionality. Bipyridine-based catalysts showed limited effectiveness, whereas polydentate aliphatic amines displayed higher activity. Kinetic studies showed linear profiles during the early stages of the polymerization before reaching a conversion plateau accountable to the depletion of the reducing agent, as confirmed by reactivation experiments. The resulting polymer (PVMA) exhibited a glass transition temperature comparable to that of poly(styrene), emerging as a potential bio-derived alternative to fossil-based thermoplastic materials. Furthermore, preliminary in vitro tests demonstrated that PVMA has potential antimicrobial activity against both Escherichia coli (Gram-negative) and Bacillus subtilis (Gram-positive). Full article

The high mortality rate from microbial infections underscores the need to discover new antimicrobials. This work produced antibacterial Chitosan biofilms with and without the incorporation of the ethanolic extract of Libidibia ferrea stem bark and its ethyl acetate and aqueous fractions. The extract and fractions were subjected to FTIR and ¹H NMR analysis. The biofilms were characterized by FTIR, scanning electron microscopy, thermogravimetry, and differential scanning calorimetry analysis. The ¹H NMR and FTIR data, as well as the colorimetric quantification of total phenolics, demonstrated the presence of phenolic compounds. Staphylococcus aureus and Bacillus cereus were the most susceptible bacteria for Chitosan/L. ferrea biofilms and fractions (growth inhibition zones values in the range of 10.8 ± 0.1 to 14.0 ± 0.1 mm, and minimum inhibitory or bactericidal concentration, MIC or MBC values of the fractions were in the range of 125 to 250 µg mL⁻¹. Only the fractions inhibited Pseudomonas aeruginosa (MIC = 250 µg mL⁻¹). Chitosan/L. ferrea biofilms exhibited efficient interactions between chitosan functional groups and secondary metabolites, good thermal stability, and increased rigidity in mechanical tests. This study reinforces the pharmacological potential of biodegradable Chitosan/L. ferrea biofilms as antibacterial agents biofilms. Full article

Trichomonas vaginalis is the causative agent of trichomoniasis, the most common non-viral sexually transmitted infection worldwide. In these cases, 5-Nitroimidazoles, particularly metronidazole (MTZ), remain the primary treatment option; however, resistance to MTZ has been increasingly reported. This study aimed to evaluate the in vitro activity of D-form synthetic antimicrobial peptides and investigate transcriptional differences associated with MTZ resistance and peptide treatment in T. vaginalis. D-form synthetic peptides (D-TN1, D-TN3, and D-TN6) developed in the R&D Laboratory of Acibadem University were tested against metronidazole-susceptible (T. vaginalis ATCC 30236) and metronidazole-resistant (T. vaginalis ATCC 50143) strains by minimum lethal concentration (MLC) assays. D-TN1 exhibited an MLC of 16 µg/mL in both strains, whereas D-TN3 and D-TN6 exhibited MLC values of 32 µg/mL and 16–32 µg/mL, respectively. Comparative transcriptomic analysis was conducted to investigate transcriptional differences. Differential gene expression analysis identified 3395 genes between the resistant and susceptible isolates and 3060 genes in the D-TN1-treated resistant isolate (FDR < 0.05, |log₂FC| ≥ 1). D-TN1 treatment in the resistant isolate was associated with downregulation of ribosomal and metabolic pathways. If confirmed with further in vivo studies, this new antimicrobial peptide may become a new therapeutic alternative in the treatment of trichomoniasis in the future. Full article

Avian infective endocarditis is an uncommon but severe disease that is typically diagnosed postmortem because of nonspecific clinical signs and rapid progression. In the present study, five broiler chickens (n = 5) from a commercial flock were examined with septicemia and lesions suggestive of endocarditis. This study reports the first molecularly confirmed and characterized case of valvular endocarditis associated with multidrug-resistant Vagococcus fluvialis in poultry and provides a comprehensive review of bacterial endocarditis in avian species. The case involved a broiler chicken that presented with sudden death and septicemic lesions, including vegetative valvular endocarditis, pericarditis, and multiorgan involvement. Bacterial isolates recovered from cardiac lesions were identified as V. fluvialis using MALDI-TOF mass spectrometry and confirmed by 16S rRNA gene sequencing. Antimicrobial susceptibility testing revealed a multidrug resistance profile, with resistance to several antimicrobial classes commonly used in poultry production. The literature review identified published studies describing avian infective endocarditis, which predominantly affects poultry and is caused mainly by Gram-positive bacteria, with clinical signs and necropsy findings largely overlapping across etiologies. These findings highlight the novelty of V. fluvialis as a potential etiological agent of avian infective endocarditis and underscores the diagnostic challenges associated with avian endocarditis, particularly when uncommon pathogens are involved, and underscore the importance of advanced identification methods for an accurate etiological determination. Collectively, the results of this study expand the spectrum of bacterial species associated with avian infective endocarditis and emphasize the relevance of antimicrobial resistance and improved diagnostic strategies in poultry health and disease surveillance. Full article

Lactic Acid Bacteria (LAB)-derived antimicrobial compounds are recognized as a promising source of novel antimicrobial agents, particularly for the treatment of Methicillin-Resistant Staphylococcus aureus (MRSA), where the mode of action and associated cellular effects remain largely unexplored. This study aims to evaluate antibacterial activity of Limosilactobacillus fermentum YTPP05 isolated from pickled radish against MRSA. Upon the initial antibacterial evaluations, it was found that strain YTPP05 inhibited the growth of MRSA isolates. Multiplex PCR identified multiple resistance genes in our MRSA strains, including mecA, blaZ, and aacA genes, aligning with antibacterial susceptibility profiles determined by the disc diffusion assay. An agar overlay assay showed that YTPP05 possessed antibacterial potential, with the largest inhibition zone diameters of 40.83 ± 8.43 mm, while the inhibition zones of the Cell Free Supernatant (CFS) of YTPP05 by an agar well diffusion were 27.16 ± 2.93 mm against the MRSA isolates. The minimum inhibitory concentration and minimum bactericidal concentration of YTPP05-derived CFS were 125 mg/mL. Scanning Electron Microscopy (SEM) demonstrated YTPP05 extracts caused cell membrane disruption, bubble-like protrusion, and cell lysis. Collectively, this study highlights the anti-MRSA potential of YTPP05 as an alternative antimicrobial agent for combating MRSA infections. Full article

Bacillus species are extensively studied, utilized, and commercialized biocontrol agents, demonstrating significant effectiveness in managing a variety of plant diseases. Bacillus possesses a robust intrinsic biosynthetic ability, capable of producing a diverse array of antimicrobial metabolites, including dipicolinic acid (DPA; 2,6-pyridinedicarboxylic acid), which exhibits antifungal properties and serves as a principal structural component of Bacillus spores. This study revealed that DPA exhibits significant antibacterial activity against the hazardous soybean pathogen Xanthomonas citri pv. glycines (Xcg), with an EC₅₀ value of 53.2 μg/mL. DPA inhibited Xcg swimming motility, extracellular protease activity, and biofilm formation, while inducing significant membrane irregularities in Xcg cells. DPA treatment downregulated the expression of several Xcg membrane integrity-related genes, including cirA, czcA, czcB, emrE, and tolC. The preventive and curative application of 500 μg/mL DPA reduced Xcg symptoms by 82.7% and 83.8%, respectively, and induced the accumulation of the isoflavone genistin in soybean leaves. DPA exhibited only weak toxicity in the zebrafish model, suggesting its potential suitability for agricultural commercialization. Overall, this study provides the first detailed characterization of the antibacterial mechanism of DPA against a phytopathogenic bacterium, Xcg, and identifies DPA as a previously underexplored antibacterial metabolite from Bacillus and Paecilomyces with potential for disease management. Full article

Oral infections caused by antibiotic-resistant bacteria represent an emerging biomedical hazard and growing challenge for modern dentistry. To address this issue, Ag– and Cu–ZnO nanocomposites (NCs) were synthesized using ZnO carrier to combat the oral pathogens Streptococcus mutans and Streptococcus sobrinus. A comprehensive analysis of chemically synthesized metal oxide nanocomposites (MONCs) was performed, combining physicochemical characterization (TEM, XRD, ζ-potential, DLS, pH, and PFO/PSO kinetic models) with biological toxicity assessment (MIC, ATR–FTIR, SEM, and FAMEs) to better understand their antimicrobial mechanisms. The results confirmed that the synthesized nanoproducts fulfill the criteria for nanomaterials (NMs) (particle size < 100 nm). Among them, Ag–ZnO exhibited the highest antibacterial activity against both strains (MIC = 50 mg L⁻¹). Kinetic modeling revealed faster and more efficient Ag ion release from Ag–ZnO NCs compared to Cu from Cu–ZnO NCs. Molecular analyses indicated strong MONC–bacterial interactions at the cell surface, leading to changes in protein secondary structures, alterations in lipid composition, and disruption of Gram-positive bacterial membranes. Additionally, Ag–ZnO inhibited chain and cluster formation in both bacterial species, while Cu–ZnO affected only S. sobrinus. Overall, Ag– and Cu–ZnO NCs show strong potential as antimicrobial agents against oral pathogens. Full article

The growing need for sustainable strategies to reduce agro-industrial waste has stimulated interest in valorizing winery by-products as sources of high-value bioactive compounds. Wine lees, rich in phenolic compounds with well-documented antimicrobial activity, remain largely underutilized in the development of functional materials. In most cases, incorporation of bioactive agents relies on physical adsorption, which often results in weak adhesion and limited durability. In this study, phenolic extracts derived from wine lees and grape seed extract were incorporated into bacterial cellulose (BC) to develop bioactive materials with antimicrobial and antioxidant functionality. Two strategies were investigated: (i) direct immersion of BC in phenolic extracts and (ii) incorporation of extracts in BC membranes pre-modified with carboxymethyl cellulose (CMC) to enhance phenolic affinity and retention. The resulting materials were characterized for total phenolic content, antioxidant activity, and antimicrobial performance against bacterial strains (Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus). CMC-pretreated membranes significantly enhanced phenolic incorporation and antimicrobial performance, achieving a 99.9% reduction in E. coli after 24 h, while S. Typhimurium and S. aureus counts were below the detection limit (LOD < 1.0 log₁₀ CFU/mL). These findings demonstrate the potential of wine lees as a sustainable source of bioactive compounds for the development of antimicrobial cellulose-based materials, supporting circular bioeconomy strategies and their potential application in food packaging. Full article