Yasemin Bölükbaşı

Dr. Yasemin Bölükbaşı

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 October 2021 in Mikrobiyoloji Bulteni
Verified
Journal Article
Closed access
YBYasemin Bölükbaşı
Yasemin Bölükbaşı
GGGonca Erkose Genc
Gonca Erkose Genc
OOOrhun Orhun
Orhun Orhun
MKMert Ahmet Kuşkucu
Mert Ahmet Kuşkucu
AÇAtahan Çağatay
Atahan Çağatay
ZEZayre Erturan
Zayre Erturan
Candida auris is a species of fungus that has gained importance in recent years owing to its ability to cause hospital infections and epidemics, resistant to antifungal agents and disinfection processes and frequently misidentified by commercial systems. Hospital outbreaks caused by C.auris have been reported from some countries. It has been determined that C.auris has lower virulence than Candida albicans; however, it is associated with high mortality rates in immunocompromised individuals. An increase in the incidence of invasive fungal infections which can lead to serious complications and death, has been identified in severe coronavirus-2019 (COVID-19) patients or immunocompromised individuals with underlying disease. Studies demonstrated an increase in the frequency of C.auris isolation in COVID-19 patients with candidemia. In this report, the first case of COVID-19 positive C.auris fungemia detected in Turkey was presented. A 71-year-old male patient with a history of myocardial infarction, diabetes mellitus, donation of a single kidney and lobectomy surgery due to lung cancer was hospitalized in the pandemic thoracic surgery service due to the findings consistent with viral pneumonia on thoracic computed tomography. Favipiravir 2 x 600 mg and intravenous dexamethasone 1 x 6 mg therapy was administered. The patient tested positive for SARS-CoV-2 polymerase chain reaction, and severe involvement of the left lung was detected in the following days. Antibiotics were administered, followed by insertion of a right jugular vein catheter and initation of tocilizumab. The patient was transferred to the intensive care unit due to increased respiratory distress. Yeast growth was detected in the patient's hemoculture. The yeast strain could not be identified using API ID 32C (bioMerieux, France) (Sacchromyces kluyveri, Candida sake, unacceptable profile), but was identified as C.auris using the VITEK MALDI TOF MS (bioMerieux, France) (99.9%) system and confirmed by sequencing. The minimum inhibitor concentration values were detected as 3 µg/ml for amphotericin B; > 256 µg/ml for fluconazole; 0.19 µg/ml for voriconazole; 0.19 µg/ml for itraconazole; 0.016 µg/ml for posaconazole; 1 µg/ml for caspofungin and 0.094 µg/ml for anidulafungin by using the antibiotic gradient method. The patient's initial treatment comprised meropenem 3 x 1 g, vancomycin 2 x 1 g, caspofungin 1 x 70 mg, and continued as caspofungine 1 x 50 mg after the loading dose, and vancomycin 1 x 1 g/48 hours from the third day of treatment. The patient died on the ninth day after developing candidemia. The present case is the first case of fungemia caused by C.auris in a COVID-19 positive patient in Turkey, and it emphasizes the need of caution for fungemia due to C.auris in intensive care units in our country which has a high COVID-19 incidence.

19 September 2023 in Healthcare
Verified
Journal Article
Open access
PDF file
BKBahar Akgün Karapınar
Bahar Akgün Karapınar
İKİlvana Çaklovica Küçükkaya
İlvana Çaklovica Küçükkaya
YBYasemin Bölükbaşı
Yasemin Bölükbaşı
SKSertaç Küçükkaya
Sertaç Küçükkaya
GGGonca Erkose Genc
Gonca Erkose Genc
BÖBetigül Öngen
Betigül Öngen
Bacteremia and fungemia are significant causes of morbidity and mortality that frequently occur as co-infections with viral respiratory infections, including SARS-CoV-2. The aim of this study was to evaluate the microorganisms that were isolated from the blood cultures of SARS-CoV-2-positive and negative patients and investigate their antimicrobial resistance patterns. A retrospective analysis was performed of 22,944 blood cultures sent to the laboratory between November 2020 and December 2021. Blood culture analyses were performed using the BD Bactec FX automated system. Identification was carried out using conventional methods, namely, VITEK-2 and MALDI-TOF MS. Antibacterial/antifungal susceptibility tests were performed according to EUCAST/CLSI recommendations. SARS-CoV-2 tests were performed with RT-PCR. Culture positivity was detected in 1630 samples from 652 patients. Of these 652 patients, 633 were tested for SARS-CoV-2; 118 (18.6%) were positive and 515 (81.3%) were negative. The bacteria and fungi that were isolated at the highest rate in SARS-CoV-2-positive patients were methicillin-resistant coagulase-negative staphylococci (MR-CoNS) (21.5%), Escherichia coli (12.4%), Klebsiella pneumoniae (12.4%), Candida albicans (1.65%), and Candida glabrata complex (1.65%), while in the negative patients, the highest rates were for E. coli (21.3%), MR-CoNS (13.5%), K. pneumoniae (12.05%), C. albicans (2.1%), Candida parapsilosis (1.1%), and Candida tropicalis (0.9%). No statistically significant difference was determined between COVID-19-positive and negative patients in terms of detection, such as with the Pseudomonas spp., Enterococcus spp., and methicillin-resistant Staphylococcus aureus isolated from the blood cultures (p > 0.05). The most common isolate was MR-CoNS in SARS-CoV-2-positive patients (p = 0.028). Acinetobacter baumannii was more frequent (p = 0.004) and carbapenem-resistant K. pneumoniae was isolated at a higher rate (60% vs. 43%) in SARS-CoV-2-positive patients compared to SARS-CoV-2-negative patients (p > 0.05). These findings highlight the fact that isolation procedures should not be disregarded and the distribution of bacterial/fungal agents of bloodstream infections and their antibiotic resistance should be followed up during a pandemic, such as in the case of COVID-19.

17 August 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
BKBahar Akgün Karapınar
Bahar Akgün Karapınar
İKİlvana Çaklovica Küçükkaya
İlvana Çaklovica Küçükkaya
YBYasemin Bölükbaşı
Yasemin Bölükbaşı
SKSertaç Küçükkaya
Sertaç Küçükkaya
GGGonca Erkose Genc
Gonca Erkose Genc
BÖBetigül Öngen
Betigül Öngen
Bacteremia and fungemia are significant causes of morbidity and mortality which frequently occur as co-infections with viral respiratory infections including SARS-CoV-2. It was aimed to evaluate the microorganisms isolated from blood cultures of SARS-CoV-2 positive and negative patients and investigate their antimicrobial resistance patterns. A retrospective analysis was performed with the total number of 22,944 blood cultures sent to the laboratory between November 2020 and December 2021. Blood cultures were performed on the BD Bactec automated system. Identification was performed using conventional methods, VITEK-2 and MALDI-TOF MS. Antibacterial/antifungal susceptibility tests were performed according to EUCAST/CLSI recommendations. SARS-CoV-2 tests were performed with RT-PCR. It was detected 1,630 culture positivity belonging to 652 patients. Totally 633 of 652 patients were tested for SARS-CoV-2; 118 (18.6%) were positive and 515 (81.3%) were negative. The bacteria and fungi isolated at the high-est rate in SARS-CoV-2 positive patients were methicillin-resistant coagulase negative staphylococci (MR-CoNS) (21.5%), Escherichia coli (12.4%), Klebsiella pneumoniae (12.4%), Candida albicans (1.65%) and Candida glabrata complex (1.65%); while in negative patients, E. coli (21.3%), MR-CoNS (13.5%), K. pneumoniae (12.05%), C. albicans (2.1%), Candida parapsilosis (1.1%) and Candida tropicalis (0.9%). The fact that the most common isolate was MR-CoNS in SARS-CoV-2 positive patients (p = 0.028); the detection of Acinetobacter baumannii was more frequent (p = 0.001) and the isolation of carbapenem-resistant K. pneumoniae was at a higher rate than in SARS-CoV-2 negative patients; also, the increase in multidrug-resistant strains indicate that healthcare-associated infec-tions should not be disregarded while focusing on the outbreak.

27 February 2026 in Antibiotics
Verified
Journal Article
Open access
PDF file
YBYasemin Bölükbaşı
Yasemin Bölükbaşı
BÖBetigül Öngen
Betigül Öngen
Background/Objectives: Acinetobacter baumannii is a leading cause of healthcare-associated infections and is frequently associated with multidrug resistance, severely limiting therapeutic options. The increasing prevalence of carbapenem-resistant A. baumannii (CRAB) has intensified interest in novel antimicrobial agents such as cefiderocol, eravacycline, and imipenem–relebactam. Methods: A total of 80 multidrug-resistant (MDR) A. baumannii isolates recovered from various clinical specimens between April 2019 and October 2023 were included. Antimicrobial susceptibility testing was performed using disk diffusion, gradient test, and broth microdilution methods in accordance with EUCAST and CLSI recommendations. The minimum inhibitory concentrations (MIC’s) for cefiderocol were evaluated with broth microdilution using iron-depleted cation-adjusted Mueller–Hinton broth as the reference method. The presence of carbapenem resistance–associated genes (blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, blaIMP, and tetA) was investigated by polymerase chain reaction. Results: All isolates were resistant to imipenem and meropenem. Colistin resistance was detected in 7.5% of isolates. According to EUCAST criteria, cefiderocol susceptibility was observed in 77.5% of isolates by microdilution and in 81.25% by disk diffusion. Eravacycline demonstrated low MIC values, with MIC50 and MIC90 of 0.25 mg/L and 0.75 mg/L, respectively. In contrast, all isolates were resistant to imipenem–relebactam. The blaOXA-23 gene was detected in 82.5% and blaOXA-24 in 17.5% of isolates, while no blaOXA-58, blaIMP, or tetA genes were identified. No statistically significant association was found between cefiderocol resistance and OXA-type carbapenemase genes. Conclusions: Cefiderocol and eravacycline demonstrated promising in vitro activity against MDR A. baumannii, including colistin-resistant isolates, whereas imipenem–relebactam showed no activity. These findings support the potential role of cefiderocol and eravacycline as alternative treatment options for CRAB infections and highlight the multifactorial nature of cefiderocol resistance beyond OXA-type carbapenemase production.