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result(s) for
"Aygun Gokhan"
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Evaluating a pathogen-specific IgG binding assay for rapid detection of healthcare-associated infections
by
Karakullukçu, Asiye
,
Dikmen, Yalım
,
Akker, Mustafa
in
631/250/2152
,
631/250/255/1318
,
631/326/2522
2026
Rapid and accurate diagnosis of healthcare-associated infections (HAIs) is an unmet need for improving outcomes in intensive care units (ICUs). Traditional culture-based methods, while the gold standard, are time-consuming and can delay therapeutic interventions. In this study, we evaluated the diagnostic utility of pathogen-specific immunoglobulin G (IgG) binding levels using an enzyme-linked immunosorbent assay (ELISA). We measured IgG binding against pathogens including
Acinetobacter baumannii
,
Klebsiella pneumoniae
,
Escherichia coli
,
Pseudomonas aeruginosa
,
Enterococcus faecalis
,
Enterococcus faecium
, and
Staphylococcus aureus
. Diagnostic performance was evaluated through receiver operating characteristic (ROC) curve analysis, with culture results as the reference. The assay demonstrated an overall diagnostic accuracy of 83.2%, with a sensitivity of 85.4%, a specificity of 81.4%, and an area under the curve (AUC) of 0.910. Pathogen-specific cutoff values ranged from 0.918 to 1.534. Especially,
A. baumannii
showed the highest performance metrics, achieving a sensitivity of 94.7%, a specificity of 93.6%, and an AUC of 0.975. The pathogen-specific IgG binding levels can offer a novel and effective diagnostic tool for the initial assessment of HAIs, enhancing early detection and improving patient management across healthcare settings.
Journal Article
Effective use of skin microbiome signatures for fingerprint identification
by
Çakan, Hüseyin
,
Yılmaz, Seda Salman
,
Aygün, Gökhan
in
Adult
,
Cascade chemical reactions
,
Dermatoglyphics
2024
Background Recent advances have increased the importance of the human microbiome, including the skin microbiome. Despite the hand microbiome research, the factors affecting the composition of the hand microbiome and their personal characteristics are incompletely known. Objectives Despite changing environmental factors and personal variation, we aimed to indicate the interpersonal distinction between skin microbiota using simple and rapid molecular methods. Methods Over a non‐consecutive 10‐day period, samples were taken from 10 adult individuals, and ribotyping analysis of the 16S and 23S genes of S. epidermidis was performed on each skin sample. Additionally, EcoRI and HindIII enzyme reactions and variable number tandem repeat (VNTR) reactions of S. epidermidis obtained from DNA samples were performed. The skin microbiomes of individuals were evaluated along with the microbiome profiles left on the surfaces they touched. Results In the environmental samples taken, it has been observed that people preserve their core skin microbiota characters and carry them to their environment. It was determined that the highest similarity rate was 77.14%, and the lowest similarity rate was 31.74%. Conclusion Our study showed that the core skin microbiota retains its characteristics and leaves traces in environments. The fact that the personal microbiome remains unchanged despite environmental differences and has characteristic features has shown that it can be used in forensic sciences to distinguish individuals from each other. These results with simple and rapid methods further increased the importance and significance of the study. The findings indicate that personal skin microbiota can provide a significant contribution to criminal investigations by increasing accuracy and reliability, especially in forensic analyses.
Journal Article
Investigating Different Clinical Manifestations of Staphylococcus aureus Infections in Childhood—Can D-Dimer and Fibrinogen Predict Deep Tissue Invasion?
by
Çokuğraş, Haluk
,
Aygün, Fatih
,
Sever, Gözde Apaydın
in
Abscesses
,
Age groups
,
C-reactive protein
2025
Background: Staphylococcus aureus is a significant pathogen causing both local and systemic infections in children, with deep tissue involvement leading to severe complications. This study aimed to assess clinical manifestations and identify risk factors for deep tissue involvement in pediatric S. aureus infections. Methods: All children between 1 month and 18 years who had S. aureus growth in blood, pus, or joint fluid culture were included. Results: A total of 61 patients (median age 55 months) were included, with 22.9% having deep tissue infections. Osteoarticular infections, pyomyositis, and pulmonary involvement were common. Deep-seated infections were significantly associated with community-acquired infections and positive hemocultures after 72 h (p < 0.01). Laboratory results showed significantly higher levels of C-reactive protein, sedimentation rate, D-dimer, and fibrinogen in the group with deep-seated infections (p = 0.02, p = 0.018, p = 0.01, and p = 0.015, respectively). The decision tree model showed that the first indicator of deep-seated infection was a D-dimer level above 1.15 mg/L, followed by a fibrinogen level above 334 mg/dL. Conclusions: Deep-seated S. aureus infections are more frequently associated with community-acquired cases, persistent hemoculture positivity, and methicillin-susceptible Staphylococcus aureus (MSSA) strains. Additionally, elevated D-dimer and fibrinogen levels may serve as valuable markers for identifying deep-seated infections in pediatric patients.
Journal Article
Change in species distribution and antifungal susceptibility of candidemias in an intensive care unit of a university hospital (10-year experience)
2021
Candidemia is a nosocomial infection mostly found in critically ill patients. Our objectives were to evaluate the change in distribution and resistance profile of Candida spp. isolated from candidemic patients in our intensive care unit over two 5-year periods spanning 15 years and to evaluate the risk factors. Records from the microbiology laboratory were obtained, from January 2004 to December 2008 and from January 2013 to December 2017, retrospectively. Antifungal susceptibility was performed by E-test and evaluated according to EUCAST breakpoints. A total of 210 candidemia cases occurred; 238 Candida spp. were isolated in 197 patients (58.8% male; mean age, 59.2 ± 19.6 years). The most predominant risk factor was central venous catheter use. Species distribution rates were 32%, 28%, 17%, and 11% for C. albicans (n = 76), C. parapsilosis (n = 67), C. glabrata (n = 40), and C. tropicalis (n = 27), respectively. Resistance rate to anidulafungin was high in C. parapsilosis over both periods and increased to 73% in the second period. Fluconazole showed a remarkable decrease for susceptibility in C. parapsilosis (94 to 49%). The prevalence of MDR C. parapsilosis (6%/33%) and C. glabrata (0%/44%) increased in the second period. We observed a predominance of non-albicans Candida spp., with C. parapsilosis being the most frequent and C. glabrata infections presenting with the highest mortality. High level of echinocandin resistance in C. parapsilosis and increasing prevalences of MDR C. parapsilosis and C. glabrata seem emerging challenges in our institution.
Journal Article
Syndromic Testing—The Evaluation of Four Novel Multiplex Real-Time Polymerase Chain Reaction Panels
by
Safak, Birol
,
Tosun, Ayse Istanbullu
,
Aygun, Gokhan
in
Acids
,
Biological products
,
Campylobacter
2025
Background: If used in the right clinical context, PCRs carry great potential in rapidly diagnosing various infectious diseases. Objectives: We aimed to evaluate the clinical performance of four novel multiplex real-time PCR (qPCR) assays in the direct detection of pathogens in whole blood, cerebrospinal fluid, respiratory specimens, and stool samples. Methods: Spiked negative clinical specimens were used for the evaluation. Clinical samples for the comparative assessment of culture and molecular analyses were simultaneously examined. RINATM robotic nucleic acid isolation system and Bio-Speedy® multiplex qPCR panels (Bioeksen R&D Technologies, Turkey), and the LightCycler® 96 Instrument (Roche, USA) were used for the molecular testing. Results: No qPCR assays produced positive results for the samples spiked with the potential cross-reacting pathogens. The limit of detection (LOD) of the assays changed with the use of 10 and 100 pathogens/mL sample based on the target and sample type. The relative sensitivity and specificity of the assays were, respectively, 82% and 94% for blood, 97.1% and 99.3% for blood culture, 94% and 98% for stool, 96% and 97% for CSF, and 97% and 96% for respiratory specimens. Conclusions: The panels evaluated allow the direct molecular analysis of 10 samples from four clinical syndromes on the same run in 3 h with high clinical performance. The number and variety of samples in a single run enable healthcare providers to rapidly and efficiently diagnose and treat various infections.
Journal Article
Colistin resistance increases 28-day mortality in bloodstream infections due to carbapenem-resistant Klebsiella pneumoniae
by
Şen Sümeyye
,
Tabak Fehmi
,
Bilgül, Mete
in
Antibiotics
,
Antiinfectives and antibacterials
,
Antimicrobial agents
2021
Mortality due to K. pneumoniae bacteremia is on rise, particularly in regions with high rates of carbapenem and colistin resistance. We aimed to define risk factors for colistin resistance and its impact on mortality. Patients diagnosed with “carbapenem-resistant K. pneumoniae (CRKp)” bacteremia between 2014 and 2018 were divided into two groups as “colistin susceptible (ColS)” and “colistin resistant (ColR)” based on broth microdilution method. Retrospective case-control study was conducted to compare characteristics and outcomes. Multiple logistic regression model was used to define independent risk factors for acquired colistin resistance and Cox proportional hazard model for 28-day mortality. A total of 82 patients (39 ColS and 43 ColR) were included. Mean age was 61.5 years, and 50 (61%) were male. Colistin resistance was significantly increased with duration of hospital stay (p = 0.007) and prior colistin use (p = 0.007). Overall, the 28-day mortality rate was 66%. Age (p = 0.014) and colistin resistance significantly increased 28-day (p = 0.009) mortality. Microbiological response to treatment within 7 days favors survival. PFGE analysis revealed an outbreak with K. pneumoniae ST78 and ST45 clones. Patients treated with combined antimicrobials had significantly lower 28-day mortality (p = 0.045) in comparison to monotherapy. However, types of combinations did not show significant superiority on each other. Colistin resistance increases 28-day mortality in CRKp bacteremia. Although combined regimens are more effective than monotherapy, existing antibacterial combinations have no apparent superiority to each other. New treatment options are pivotal.
Journal Article
Thyroid abscess due to Eikenella corrodens in a pediatric patient
2019
Eikenella corrodens is one of the HACEK bacteria that is commensal microorganism of the oropharngeal flora. E. corrodens has been increasingly reported to cause pyogenic abscesses, especially in diabetic or immunocompromised adults. It is less frequently reported in immunocompotent children. Here, we report a deep neck infection, including the thyroid gland, in a previously healthy girl. E. corrodens was the only microorganism isolated in two different cultures. Antibiotic susceptibility is variable, in contrast to other oropharyngeal pathogens. Thus, to avoid delayed treatment, E. corrodens should always be considered in infections of the head and neck area.
Journal Article
Clinical outcomes of geriatric patients with COVID-19: review of one-year data
by
Karaali Ridvan
,
Veysel, Suzan
,
Bektan Kanat Bahar
in
Clinical outcomes
,
Coronaviruses
,
COVID-19
2022
AimsIn this study, we aimed to reveal mortality rates and factors affecting survival in geriatric patients infected with COVID-19.MethodsThis is a retrospective study of 873 geriatric patients with COVID-19 who were hospitalized between March 11, 2020 and March 11, 2021. Demographic, clinical, laboratory data, and treatment options were obtained from electronic medical records. Multivariate logistic regression was used to explore the risk factors for in-hospital death.ResultsDuring the specified period, 643 patients were discharged, and 230 patients died in the hospital. The mean age was 75.08 ± 7.39 years (mean ± SD) and 51.8% were males. We found that older age (≥ 85), polypharmacy, dyspnea, abnormal thorax computed tomography (CT), lower doses of anticoagulation, and high values of white blood cell, aspartate aminotransferase, C-reactive protein, lactate dehydrogenase, ferritin were associated with a significant increase in mortality (P < 0.001 for all). Although all of these values were significant in multivariate logistic regression analysis, the most important ones were dyspnea (Odds ratio (OR) 57.916, 95% confidence interval (CI) 23.439–143.104, P < 0.001), polypharmacy (OR 6.782, 95% CI 3.082–14.927, P < 0.001), and thorax CT classification (typical; OR 9.633, 95% CI 2.511–37.122, P < 0.001).ConclusionOlder age, polypharmacy, dyspnea, and abnormal thorax CT were the most significant mortality criteria and in addition appropriate anticoagulant use was associated with reduced mortality. Identifying the risk factors to predict mortality in older adults with COVID-19 is important to treat future cases successfully.
Journal Article
Untreated herpes simplex virus encephalitis without a fatal outcome
by
Kurt, Ahmet Furkan
,
Kaya, Abdurrahman
,
Sar, Mehmet
in
Acyclovir
,
Acyclovir - therapeutic use
,
Adult
2021
Herpes simplex virus encephalitis (HSE) is the most common sporadic fatal encephalitis. Although timely administered acyclovir treatment decreases mortality, neuropsychiatric sequelae is still common among survivors. Magnetic resonance imaging is frequently utilized for the diagnosis of HSE, which typically involves temporal lobe(s) and can be mixed with brain tumors involving the same area. Here, we report a case of HSE, who received acyclovir with a delay of 90 days because of presumptive tumor diagnosis and survived with minimal sequelae.
Journal Article
Resistance Genes and Mortality in Carbapenem-resistant Klebsiella pneumoniae Bacteremias: Effects of the COVID-19 Pandemic
by
Otlu, Barış
,
Tabak, Fehmi
,
Kuşkucu, Mert Ahmet
in
Adult
,
Aged
,
Anti-Bacterial Agents - pharmacology
2024
Emerging carbapenem-resistant
(
) (CRKP) bacteremias are presenting significant public health risks due to limited treatment options and increased mortality.
isolates exhibit carbapenem resistance rates that vary from 25% to 50% throughout the European continent, including our country.
To assess the characteristics of CRKP bacteremia, a condition that has recently demonstrated an increasing prevalence in our center. We sought to ascertain the resistance rates of isolated strains to antibiotics other than carbapenems, identify the responsible carbapenemase genes, evaluate the efficacy of antibiotics, determine mortality rates, explore clonality among strains, and investigate the influence of the COVID-19 pandemic on all these factors.
Retrospective observational study.
This study included patients aged 18 and older who had experienced meropenem-resistant
bacteremia. Meropenem resistance was confirmed by employing the Kirby-Bauer disk diffusion method. Meropenem minimum inhibitory concentration (MIC) levels were determined using the gradient test, while colistin MIC levels were ascertained using the disk elution technique. Carbapenemase genes were evaluated via colony polymerase chain reaction (PCR), and clonality analysis was performed using the arbitrarily primed PCR technique.
The study comprised 230 patients, with a mean age of 63.1 ± 15.9 years, of whom 58.7% were male. Oxacillinase-48 (OXA-48) was detected in 74.8% of the patients, New Delhi metallo-beta-lactamase (NDM) in 12.6%, OXA-48 + NDM in 7.8%, and KPC in 4.8%. The 14-day and 30-day mortality rates were 57% and 69.6%, respectively. Multivariate analysis of the 30-day mortality revealed several crucial factors, including bacteremia development in the intensive care unit, the occurrence of bacteremia during the COVID-19 pandemic, polymicrobial bacteremia, the use of indwelling intravenous catheters, a platelet count of ≤ 140,000/μl, procalcitonin levels of ≥ 6 μg/l, and a Charlson comorbidity score ≥ 3. Notably, the
and
genes were upregulated significantly during the COVID-19 pandemic, while the
gene groups were downregulated. Additionally, both 14-day and 30-day mortality rates increased significantly.
In this study, the most prevalent carbapenemase gene was OXA-48; however, there has been a recent increase in
genes. No dominant epidemic strain was identified through clonality analysis. The clustering rate was 68% before the pandemic, increasing to 85.7% during the pandemic. The significance of infection control measures is underscored by the rise in both clustering and mortality rates during the COVID-19 pandemic.
Journal Article