Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Whole-genome characterization of clinical Enterococcus faecalis and Staphylococcus epidermidis Isolates reveals mecA-positive E. faecalis and a shared lnu(A)–rep7a resistance plasmid in Türkiye
Ejder, Nebahat; Özad Düzgün, Azer
Background: This study aimed to genomically characterize clinical Enterococcus faecalis and Staphylococcus epidermidis isolates obtained from aspirate and sputum samples at Bayburt State Hospital, focusing on antimicrobial resistance genes, virulence factors, and mobile genetic elements. Methods: Whole-genome sequencing (WGS) was performed on the isolates, and antimicrobial resistance genes, virulence determinants, multilocus sequence types (MLST), plasmid replicons, and mobile genetic elements were identified using bioinformatics tools. Results: The E. faecalis E5 (ST64) isolate, recovered from an aspirate sample, carried multiple antimicrobial resistance genes, including mecA, vanT, erm(B), tet(M), and qacA, along with a diverse virulence gene repertoire (cyl, ebp, ace, and agg), mobile genetic elements (Tn6009, ISL1a3), and four plasmid replicons (rep19C, rep9C, repUS43, and rep7a). The E. faecalis E184 and E187 isolates (ST124), obtained from sputum samples, harbored fewer acquired resistance genes but shared gyrA (T672A) and parC (V307I) mutations associated with fluoroquinolone resistance. The S. epidermidis ST59 isolate carried resistance genes lnu(A), fosB, and qacD, together with the plasmid replicon rep7a and insertion sequence ISSau4. The co-occurrence of lnu(A) and the rep7a plasmid in both species suggests a potential pathway for interspecies transmission of resistance determinants. Conclusions: This study reports the genomic detection of mecA in an E. faecalis isolate from Türkiye based on WGS analysis. However, this finding is based solely on genomic data and lacks phenotypic or experimental validation. The detection of a shared plasmid-associated resistance element (lnu(A)–rep7a) in both E. faecalis and S. epidermidis highlights the potential for interspecies resistance gene flow within the hospital environment.
- MakaleYalnız künye2026Green Synthesis of Multifunctional Ag/ZnO Nanoparticles Using Vitis labrusca L. Extract: Bioactivity, Malachite Green Adsorption, and HMF Removal
Hammoudeh, Rama; Bozbeyoğlu, Pınar; Karpuz, Ömer; Gül, Abdulkadir; Ejder, Nebahat; Baltacı, Cemalettin
In this study, Ag/ZnO nanoparticles (Ag/ZnO NPs) were synthesized via a green route using Vitis labrusca L. extract and evaluated for their bioactive, environmental performance. BM-1 and BM-2 were prepared under different precursor/extract ratios and pH conditions to assess the influence of synthesis parameters. UV–Vis, FT-IR, XRD, HRTEM, DSC, and EDX analyses indicated the successful formation of Ag/ZnO nanostructures with distinct physicochemical features. HRTEM analysis determined that BM-1 exhibited an average particle diameter of 23.18 ± 11.84 nm, while BM-2 demonstrated a mean size of 6.14 ± 1.30 nm. The corresponding relative size-dispersion values were 0.261 for BM-1 and 0.045 for BM-2, indicating a more uniform particle size distribution for BM-2. Antioxidant assays showed that BM-2 exhibited the strongest overall antioxidant performance in DPPH, ABTS•⁺, Fe3+, and Cu2+ assays. Both NPs exhibited antibacterial activity against Gram-positive and Gram-negative bacteria and showed stronger effects than the grape extract alone. Cytotoxicity assays revealed dose-dependent inhibition in A549 and HeLa cancer cells, while lower toxicity was observed in normal ARPE-19 cells, suggesting cell-type-dependent biological response. In adsorption experiments, the NPs effectively removed malachite green, with isotherm analysis providing stronger support for the Langmuir model for BM-1 and comparable Langmuir and Freundlich fits for BM-2, while the pseudo-second-order model provided the best description of the adsorption kinetics. The maximum dye adsorption capacities were 85.5 mg/g for BM-1 and 101.3 mg/g for BM-2. Under optimum conditions (5.0 g/L NPs, 240 min), the highest HMF removal efficiencies reached 44.49% for BM-2 in standard aqueous solutions, whereas competitive matrix interactions in apple juice limited the maximum efficiency to 29.27%. Overall, this study highlights the value of integrating green synthesis, bioactivity, dye adsorption, and food-related contaminant removal within a single Ag/ZnO nanoplatform.
- MakaleAçık Erişim2024Determination of the Cytotoxicity and Antibiofilm Potential Effect of Equisetum arvense Silver Nanoparticles
Akar, Zeynep; Akay, Seref; Ejder, Nebahat; Özad Düzgün, Azer
This study aimed to synthesize and characterize silver nanoparticles (AgNPs) by green synthesis from Equisetum arvense (Ea) extracts and to investigate their cytotoxicity, antibiofilm activity, and α-glucosidase enzyme inhibition. Diverse characterization techniques were applied to verify the production of nanoparticles. SEM examination confirmed that the size of nanoparticles is in the range of 40–60 nm. Also, interactions between silver and natural compounds of plant extract were confirmed through FT-IR and EDX analyses. It was determined that Equisetum arvense silver nanoparticles had antibiofilm activity against three different clinical strains with high biofilm-forming ability. AgNPs reduced the biofilm-forming capacity of clinical A. baumannii isolate with strong biofilm-forming capacity by approximately twofold, while the capacity of clinical K.pneumonaie and E.coli isolates decreased by 1.5 and 1.2 fold, respectively. The α-glucosidase enzyme inhibition potential of the AgNPs, which is determined as 93.50%, was higher than the plant extract with, and the α- 30.37%. MTT was performed to assess whether incubation of nanoparticles with A549 and ARPE-19 cell lines affected their viability, and a dramatic reduction in cell growth inhibition of both A549 and ARPE-19 cells was observed. It has been shown that A549 cells treated with 200 and 150 µg/mL nanoparticles had less cell proliferation compared to control cells at 24-h and 48-h incubation time. According to these results, Ea-derived AgNPs appear to have potential anticancer activity against A549 cancer cells. Investigating the effects of green synthesis nanoparticles on microbial biofilm and various tumors may be important for developing new therapies. The outcomes of this study have showed that Ea-AgNPsmay have a high potential both in the treatment of pathogenic strains that form biofilms, as well as in anticancer therapy use.