NEBAHAT EJDER

Dr. NEBAHAT EJDER

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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27 October 2023 in Annals of Clinical Microbiology and Antimicrobials
Verified
Journal Article
Open access
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YIYunus Emre Ibik
Yunus Emre Ibik
NENEBAHAT EJDER
NEBAHAT EJDER
ESElif Sevim
Elif Sevim
ERErva Rakıcı
Erva Rakıcı
ETElif Seren Tanriverdi
Elif Seren Tanriverdi
ACAysegül Copur Cicek
Aysegül Copur Cicek
Background: This study aimed to evaluate antibiotic resistance genes and virulence genes and the clonal relationship of the carbapenem-nonsusceptible Klebsiella pneumoniae strains by molecular methods which are isolated from various clinical specimens from patients treated in tertiary care hospital in Turkey. Methods: Identification of 32 carbapenem non-susceptible K. pneumoniae were determined by VITEK-2 (BioMérieux, France) automated system. Thirteen colistin-resistant strains were tested with the broth microdilution method. Various antibiotic resistance genes and virulence genes frequently seen in carbapenem-resistant strains were screened by PCR. Immunochromatographic tests used in the rapid diagnosis of carbapenemases were compared with PCR results. In addition, PFGE, MLST and MALDI-TOF MS methods were used to determine the clonal relationship among these strains. Results: PCR demonstrated that 31 of the strains carried at least one of the carbapenemase genes. In one strain, the coexistence of blaOXA−48+NDM was shown. The most common resistance genes were determined as blaSHV (84.3%), blaCTX−M−1 (46.8%), blaOXA−48 (40.6%), blaKPC (40.6%), blaTEM (31.2%), blaNDM (18.8%) respectively. Among the virulence genes; magA (68.7%) was the most common, followed by kpn (59.3%) and K2 (9.3%). Immunochromatographic tests were found to be 100% compatible with PCR results. All colistin-resistant isolates were also found to be resistant by colistin broth microdilution. In PFGE analysis, 25 different genotypes were determined and clustering isolates were collected in 5 different clusters and the clustering rate was 35.4%. In MLST analysis, ST101 type was determined as the most common ST type with a rate of 29%. ST101 is followed by ST16, ST307, ST14, ST147, ST309, ST377, ST395 and ST2096, respectively. The compatibility rate between MALDI-TOF MS and VITEK-2 was found 94.3%, in bacterial identification. In MALDI-TOF MS typing, the maximum similarity between the strains was less than 70% and clustering not shown. Conclusion: In addition to OXA-48, which is endemic in our country, it has been determined that KPC, which is more common in the world, is becoming increasingly common in our region. ST101 type was determined as the most common type between the strains. To the best of our knowledge, this is the first study that compares these three methods in our country. There may be differences between bacterial identifications made with VITEK-2 and MALDI-TOF MS. In this study, it was observed that MALDI-TOF MS analyses were not compatible with the typing of strains according to PFGE and MLST analysis results.

1 January 2020 in Notulae Botanicae Horti Agrobotanici Cluj-Napoca
Verified
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SESaliha Ekşi̇
Saliha Ekşi̇
ÜEÜlkü Zeynep Üreyen Esertaş
Ülkü Zeynep Üreyen Esertaş
AKAli Osman Kılıç
Ali Osman Kılıç
NENEBAHAT EJDER
NEBAHAT EJDER
BUBarış UZUNOK
Barış UZUNOK
The rapid rise of resistance causes existing antibiotics to become dysfunctional. Therefore, search for new antimicrobial active ingredients has increased in recent years. In this study, flower extracts of Castanea sativa were examined for antimicrobial and anti-quorum sensing aspects. The antimicrobial properties of methanol, ethyl acetate, ethanol and hexane extracts of C. sativa against some gram-positive and gram-negative bacterial species, as well as yeasts (Candida albicans and Candida parapsilosis) were investigated by the agar well diffusion method. The minimum inhibition concentration (MIC) and minimum bactericidal concentrations (MBC) of C. sativa extracts were also determined. Chromobacterium violaceum ATCC 12472, C. violaceum 35352, C. violaceum VIR07 and C. violaceum CV026 indicator strains were used for determination of the quorum sensing inhibitions, and the Pseudomonas aeruginosa PAO1 strain was used for the swarming tests. Additionally, biofilm inhibition was detected by the spectrophotometric method using the P. aeruginosa PAO1 strain. Methanol, ethanol and ethyl acetate extracts of C. sativa was found to have high antibacterial and antifungal effects, while the methanol extract also had anti-quorum sensing, anti-swarming and biofilm inhibition effects, but no activity was found in the n-hexane extract. To the best of our knowledge this is the first report revealed that methanol extract obtained from C. sativa flowers induced anti-quorum sensing activities mainly inhibited the violacein production, swarming and biofilm formation. The present investigation provided evidence that the C. sativa flower extract maybe a potential source of antimicrobial agents. Therefore, much attention should be paid to C. sativa flower content, which could be used with high efficacy against microorganisms.

27 October 2021 in Advances in Clinical and Experimental Medicine
Verified
Journal Article
Open access
AÇAyşegül ÇİÇEK
Ayşegül ÇİÇEK
VŞVicdan Şemen
Vicdan Şemen
NENEBAHAT EJDER
NEBAHAT EJDER
DGDeniz Gündoğdu
Deniz Gündoğdu
SKSema Kalcan
Sema Kalcan
OOOsman Birol Ozgumus
Osman Birol Ozgumus
Epidemiological studies of tetracycline (TE) resistance genes and integron gene cassettes, particularly in urine samples, are limited in Turkey. To investigate antibiotic susceptibility profiles, extended-spectrum beta-lactamase (ESBL) positivity, tet gene types, class-I/-II integron gene cassettes, and clonal relationships among tet-resistant isolates of Escherichia coli from urine cultures of outpatients. Isolates were identified using conventional methods and the automated Vitek® 2 Compact system. Antimicrobial susceptibility was performed for 19 antibiotics. The ESBL production was performed using the Kirby-Bauer disk diffusion test. The double disk synergy test was used for confirmatory testing. Polymerase chain reaction (PCR) was used to determine the presence of class-I/-II integron gene cassettes and tetA, tetB and tetD resistance genes. The pulsed-field gel electrophoresis typing was performed to identify clonal relations. A total of 121 isolates were obtained and found to be resistant or sensitive to ampicillin and amikacin/imipenem. Resistance to ceftazidime, cefotaxime and ceftriaxone was determined to be 31.3%, 77.6% and 83.1%, respectively. Tetracycline resistance was detected in 82 isolates, mostly caused by the tetB gene. No tet gene was detected in the remaining 39 isolates. Although 64 out of 82 isolates carried a class-I integron, only 4 had a class-II integron (with sizes of 800-2900 base pairs). Furthermore, tet genes were identified with different size class-I integron gene cassettes. However, tet genes were not detected in any isolate identified with integron gene cassette II. Clonally, the isolates were found to be related in subgroups because they were community-acquired. This study showed that the tetB gene is most commonly found in E. coli isolates grown in urine samples from the Turkish population.

1 January 2020 in Indian Journal of Pharmaceutical Sciences
Verified
Journal Article
Open access
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NENEBAHAT EJDER
NEBAHAT EJDER
SES. Eksi
S. Eksi
Zihni Acar YazıcıZihni Acar Yazıcı
Zihni Acar Yazıcı
FBFs. Beris
Fs. Beris
SMS. Makbul
S. Makbul
BUB. Uzunok
B. Uzunok
The purpose of this study was to investigate the antiproliferative effect of the methanol and ethyl acetate extracts of Ornithogalum balansae flower and bulb against normal ARPE-19 cell line and cancer cell lines, A549, CRL-2923, HT-29 and HeLa. The cytotoxic activities of the extracts were determined using cell viability, deoxyribonucleic acid fragmentation and caspase-3 activity tests. Flower and bulb extracts exhibited dose-dependent antiproliferative effects on non-transformed and transformed cells, with greater growth inhibition in A549 lung cancer cells at lower concentrations. The IC50 values of the flower extracts against A549 cells were 1.5±0.153 and 2.2±0.503 µg/ml, and of the bulb extracts were 1.8±0.220 and 1.56±0.106 µg/ml, respectively. Against ARPE-19 cell line the IC50 values were 22.5±6.466 and 25±2.887 µg/ml for flower and 14±4.726 and 12.5±3.182 µg/ml for bulb extracts, respectively. In addition, it was observed that at concentrations ≤3.12 µg/ml there were statistically significant differences between ARPE-19 and transformed A549 cell lines (p <0.05). Finding caspase-3 activity of the methanol flower extract in A549 indicated apoptotic effects in those cells. These results showed that Ornithogalum balansae extracts could exhibit antitumor activity particularly on the A549 lung cancer cell line, a resistant cell line. Further investigations of the composition of the extracts are required to identify the effective components with antiproliferative activity, particularly on A549, the human alveolar adenocarcinoma cancer cell line. This study revealed that extracts of Ornithogalum balansae possessed considerable antiproliferative activity against A549 cells.

24 October 2024 in Life
Verified
Journal Article
Open access
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NENEBAHAT EJDER
NEBAHAT EJDER
MSMUNEVVER SOKMEN
MUNEVVER SOKMEN
FTFatma Tunali
Fatma Tunali
SKSevgi Kolaylı
Sevgi Kolaylı
AKAli Osman Kılıç
Ali Osman Kılıç
Ornithogalum is a genus of wild herb species widely used as food and in traditional medicine. This study investigated some of the biologically active properties of Ornithogalum balansae grown in the eastern Black Sea region of Türkiye. The investigations were carried out using the methanolic extracts of the plant’s aerial and bulbs (B1 and B2) parts. The phenolic composition was examined as total phenolic content (TPC), total flavonoid content (TFC), and HPLC-PDA. The antioxidant capacity of the extracts was tested based on ferric reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging methods. The anti-proliferative activity was tested against metastatic cell lines H1299 and H209, non-small-cell lung A549, and fibroblast MRC-5 cell lines using MTT and trypan blue methods. Wound-healing and invasion chamber assays were used to determine the inhibitory effects of the extracts on migration and invasion, respectively. The extract of the aerial part contained a large number of phenolic substances and high antioxidant capacity. The extract exhibited a significant anti-proliferative effect on the human lung cancer cells (A549 and H209), with IC50 values of 0.97 ± 0.04 and 1.06 ± 0.07 µg/mL, respectively. Moreover, the aerial part exhibited inhibition of migratory and invasive capacities in A549 cells at a concentration of 1.50 µg/mL. The findings associated with O. balansae suggest a promising therapeutic potential against lung cancer cells.

31 July 2019 in The Journal of Infection in Developing Countries
Verified
Journal Article
Open access
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AÇAhmet Çalışkan
Ahmet Çalışkan
AÇAyşegül Çopur Çicek
Ayşegül Çopur Çicek
NENEBAHAT EJDER
NEBAHAT EJDER
AKAlper Karagöz
Alper Karagöz
ÖKÖzlem Kirişci
Özlem Kirişci
SKSelçuk Kılıç
Selçuk Kılıç
Introduction: Stenotrophomonas maltophilia, which is able to form a biofilm, has mostly been related to catheters when it is the agent in hospital infections; these infections generally present as bacteremia and pneumonia, which may progress with complications and result in death. Methodology: The study included 153 S. maltophilia strains isolated from clinical samples sent to our hospital laboratory between 1 January 2014 and 30 June 2018. The bacteria were identified and their antibiotic sensitivity was determined using the VITEK-2 automated system. PFGE (Pulsed Field Gel Electrophoresis): The strains isolated from 34 patient clinical samples and from 1 patient bedcover were taken for PFGE examination. Results: The TMP/SXT and levofloxacin sensitivity of 153 S. maltophilia strains was examined. TMP/SXT resistance was determined to be 39% and levofloxacin resistance at 5%. Among 35 S. maltophilia strains, seven genotypes were identified using the PFGE method. While three strains showed a specific genotype profile, the other 32 were determined to consist of four clusters. The cluster rate was therefore 91.4% (32/35). Conclusions: There was a clonal relationship between the vast majority of the 35 S. maltophilia isolates, which suggests that there was a cross-contamination problem in the hospital. One strain (#4) was identified by dendrogram analysis showed a high rate of similarity to the other strains and was determined to be the common source of the cross-contamination.