WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14627/6
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Article Machine Learning Model for Predicting Multidrug Resistance in Clinical Klebsiella pneumoniae Isolates(MDPI, 2026) Akkaya, Yuksel; Aydin, Irfan; Tanyildizi-Kokkulunk, Handan; Erturk, Ayse; Kilic, Ibrahim HalilBackground/Objectives: Klebsiella pneumoniae is an opportunistic pathogen increasingly resistant to carbapenems and broad-spectrum antibiotics, complicating timely infection management. In critical cases like septic shock, where initiating effective antibiotics within 3 h improves survival, culture-based resistance testing is often too slow. This study evaluates machine learning (ML) algorithms for faster antimicrobial resistance prediction than conventional methods. Methods: In this retrospective study, antibiogram results of 607 Klebsiella pneumoniae isolates collected between 2017 and 2024 were combined with demographic and clinical information of the patients from whom the isolates were obtained. Four different ML algorithms, namely Decision Tree (DT), Support Vector Classifier (SVC), K-Nearest Neighbors (KNN) and Random Forest (RF), were applied to classify the resistance status for 22 antibiotics. Model performances were evaluated using accuracy, precision, recall, F-score, AUC and feature importance metrics. Results: The RF model showed the highest overall performance in accurately predicting resistance to 22 antibiotics, achieving an average AUC value of 0.96. In particular, it predicted resistance to treatment-critical antibiotics such as Ertapenem (100%), Imipenem (93%) and Meropenem (95%) with high accuracy. Conclusions: ML models, especially RF, offer a powerful tool for rapid antibiotic resistance prediction, supporting accurate empirical treatment decisions and antimicrobial stewardship.Article Evaluation of Octenidine Dihydrochloride-Induced Cytotoxicity, Apoptosis, and Inflammatory Responses in Human Ocular Epithelial and Retinal Cells(MDPI, 2025) Ciftci, Ihsan Hakki; Deveci Ozkan, Asuman; Erman, Gulay; Kilbas, Imdat; Aydemir, OzlemBackground/Objectives: Octenidine dihydrochloride (OCT-D) is a broad-spectrum antiseptic with high chemical stability, low toxicity, and no reported microbial resistance, making it a strong candidate for use on mucosal surfaces. Despite increasing interest in its potential ophthalmic applications, limited data exist regarding its cellular effects on ocular tissues. This study aimed to investigate the cytotoxic, apoptotic, inflammatory, and transcriptional responses induced by OCT-D in human conjunctival (IOBA-NHC) and retinal pigment epithelial (ARPE-19) cells. Methods: Cells were exposed to varying concentrations of OCT-D, and viability was assessed using the WST-1 assay to determine IC50 and IC50/2 values. These concentrations were subsequently used in molecular assays. Pro-inflammatory cytokines (IL-6, IL-1 beta, TNF-alpha, IFN-gamma) were quantified by ELISA. Apoptotic activation was evaluated through caspase-3/7 activity assays. Gene expression analysis of apoptotic (Bax, Bcl-2), DNA damage-related (ATM, Rad51), and inflammatory markers was performed using RT-qPCR. Results: OCT-D induced a marked, dose-dependent reduction in cell viability in both cell lines, with ARPE-19 showing greater sensitivity. Caspase-3/7 activity increased significantly at IC50 and IC50/2, confirming intrinsic apoptotic activation. OCT-D markedly suppressed the release of key inflammatory cytokines and downregulated transcription of inflammatory genes. RT-qPCR revealed upregulation of pro-apoptotic and DNA damage-associated genes, demonstrating coordinated activation of apoptotic and genomic stress pathways. Conclusion: OCT-D triggers integrated cytotoxic, apoptotic, and immunomodulatory responses in conjunctival and retinal epithelial cells. While these findings provide important mechanistic insights into OCT-D's cellular effects, further studies using primary cells, advanced 3D ocular models, and disease-relevant systems are required to support its potential translational use in ophthalmology.Article In Vitro Investigation of the Effects of Octenidine Dihydrochloride on Nasal Septum Squamous Carcinoma Cells(MDPI, 2025) Ciftci, Ihsan Hakki; Ozkan, Asuman Deveci; Erman, Gulay; Kilbas, Elmas Pinar Kahraman; Koroglu, Mehmet; Kahraman Kilbas, Elmas Pinar; Deveci Ozkan, AsumanBackground/Objectives: The aim of this study was to investigate the cytotoxic, genotoxic, apoptotic, and anti-inflammatory effects of the antiseptic agent octenidine dihydrochloride (OCT-D) on the RPMI-2650 cell line derived from human nasal mucosa in vitro. Methods: RPMI-2650 cells and Human Umbilical Cord Endothelial Cells (HUVECs) were treated with various concentrations of OCT-D (0.00625-0.4%) for 12 and 24 h. Cell viability was assessed using the WST-1 assay, while DNA damage was assessed using the comet and micronucleus (MN) assays. Apoptotic activity was determined using Annexin V flow cytometry and fluorescence microscopy. Intracellular reactive oxygen species (ROS) levels were measured, and inflammatory cytokines (IL-1 beta, IL-6, TNF-alpha, and IFN-gamma) were measured by Enzyme-Linked Immunosorbent Assay (ELISA). The mRNA expression of genes associated with apoptosis, oxidative stress, and inflammation was analyzed using RT-PCR. Results: OCT-D caused dose- and time-dependent cytotoxicity, and RPMI-2650 cells showed greater resistance compared to HUVECs. While a strong apoptotic response was observed in HUVECs, RPMI-2650 cells exhibited limited apoptosis. OCT-D was found to cause dose-dependent DNA damage and an increase in MN in both cell lines. OCT-D significantly reduced cytokine levels and ROS production in both cell types. RT-PCR results supported its anti-inflammatory and antioxidant effects at the molecular level. Conclusions: In conclusion, this study demonstrated that OCT-D exhibited minimal cytotoxic and apoptotic effects in RPMI-2650 cells, but affected vascular structure by inducing apoptosis in endothelial cells. These findings provide important evidence that OCT-D can be used as a potential adjunctive agent in nasal treatments, and these data need to be supported by preclinical and clinical studies.Article Evaluation of the Relationship Between Job Stress Level, Adherence to the Mediterranean Diet, and Phytochemical Index(MDPI, 2025) Cetiner Bingul, Bengi; Bas, MuratBackground/Objectives: Job stress negatively affects physical and psychological health and can lead to behavioral changes such as unhealthy eating. This study aimed to evaluate the relationship between job stress levels, adherence to the Mediterranean diet, and the phytochemical index (PI). Methods: The study included 200 healthy individuals aged 18-50 working at the Tuzla Gum Factory. Data were collected through demographic and dietary questionnaires, two-day 24-h food records, PI values, and anthropometric measurements. Job stress was assessed using the Job Stress Scale, and Mediterranean diet adherence was assessed with the Mediterranean Diet Adherence Questionnaire. Results: Waist and hip circumference, waist/hip ratio, and BMI were significantly higher in individuals with high levels of job stress (p < 0.01). Unskilled workers reported higher stress than professionals (p < 0.01). Significant differences were found in carbohydrate and fiber intake among males and in energy, protein, carbohydrate, and vitamin A intake among females with varying stress levels (p < 0.01). No significant difference in Mediterranean diet adherence was observed between medium and high stress groups. However, women had higher adherence and PI scores than men (p < 0.01). Diet adherence was better among managers than service-sales and technical staff (p < 0.01). PI scores were higher in medium stress than high stress individuals (p < 0.05) and in those with a higher BMI compared to a normal BMI (p < 0.01). Conclusions: Job stress influences both anthropometric parameters and dietary habits. Effective stress management may improve adherence to the Mediterranean diet and phytochemical intake. Workplace strategies supporting healthy eating behaviors are recommended.Article Citation - WoS: 2Citation - Scopus: 2Twenty-Year Course of Antifungal Resistance in Candida Albicans in Türkiye: A Systematic Review and Meta-Analysis(MDPI, 2025) Kilbas, Imdat; Kahraman Kilbas, Elmas Pinar; Horhat, Florin George; Ciftci, Ihsan HakkiThis study aimed to systematically evaluate the resistance rates of Candida albicans to various antifungals based on studies conducted in Turkiye and published between 2005 and 2025 and to analyze the factors contributing to resistance. A systematic literature search was conducted using various keywords in electronic databases (PubMed, Embase, Web of Science, EBSCO, Scopus, Turk Medline and Google Scholar). A total of 42 studies were included in the meta-analysis according to the determined criteria. The quality of the studies was assessed using the Joanna Briggs Institute checklist, and the analyses were performed using appropriate statistical software. The highest resistance rates for fluconazole, itraconazole, and voriconazole were observed in the Aegean and Marmara regions. In the analyses performed with the random-effects model, heterogeneity was found to be high for itraconazole, fluconazole, posaconazole, voriconazole, and caspofungin, and the strongest explanatory variable of this heterogeneity was the geographical region variable. In our study, we determined that antifungal resistance in C. albicans strains in Turkiye is generally low; however, an increasing trend has been observed over the years, especially in amphotericin B resistance. Although the low resistance rates to major antifungal agents such as fluconazole, voriconazole and echinocandins are promising, regional differences and methodological heterogeneity necessitate the development of treatment strategies based on local data.