Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2026Effects of sunlight ripening process on the biological activities of persimmon (Diospyros kaki L.) peel and pulp extracts
Kardil, Uğur; Akar, Zeynep; Düzgün, Azer Özad
The aim of the study was to evaluate the biological properties of the peel and pulp extracts of persimmons, with consideration of the impact of different ripening conditions (B: on-branch ripened and S: sunlight ripened). The data demonstrated that the sunlight ripened persimmon peel (S. peel) extract exhibited a higher total phenolic and flavonoid content, with 157 and 7.3 µg/mL GAE respectively. The S. peel extract exhibited the highest antioxidant activity, exhibiting 1.1578 mg/mL IC50, 54.095 and 0.0262 µM Trolox equivalent (TE)/g fresh weight (FW), as determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging assay, ferric reducing antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) respectively. LC-MS/MS analysis revealed that the peel and pulp phenolic composition of persimmon ripening process different conditions changed. The activity of protocatechuic, chlorogenic, caffeic and ferulic acids identified in persimmon extracts was determined by HPLC-DAD-FRAP assay. ICP-OES analysis revealed that potassium exhibited the highest mineral content of persimmon, with values ranging from 575.680 to 2031.360 mg/kg. The S. peel extract was more inhibitory activity against bovine carbonic anhydrase (BCA) and α-glucosidase then other extracts. Moreover, the S. peel extract was found to demonstrate the highest level of antibiofilm activity, reducing the strong biofilm formation capacity of the A. baumannii isolate to negative, both qualitatively and quantitatively. The study suggests that the ripening of persimmon fruit in sunlight may increase biological activity and may be useful in the prevention and treatment of diseases associated with oxidative damage, diabetes and bacterial infections.
- MakaleAçık Erişim2025Assessment of antioxidant, antimicrobial, antibiofilm, carbonic anhydrase and α-glucosidase inhibitory activities of Alchemilla vulgaris L. extracts
Düzgün, Azer Özad; Akar, Zeynep; Kardil, Ugur
This study was to investigate the biological properties (antioxidant, enzyme inhibitory and antimicrobial activity) of water extract (WE), 50:50% water:ethanol extract (WEE) and ethanol extract (EE) of aerial parts of Alchemilla vulgaris L. which was traditionally used to alleviate and treat many diseases. The WEE extract exhibited the highest total phenolic content (TPC), with a value of 612 µg/mL GAE, while the EE extract demonstrated the highest total flavonoid content (TFC), with a value of 0.086 µg/mL GAE. Also, the data demonstrated that the WEE extract exhibited the highest radical scavenging capacities and antioxidant activities, exhibiting 0.0056, 0.0028 mg/mL SC50 and 267, 0.081 μM TEAC, as determined by the DPPH, ABTS, FRAP and CUPRAC assays, respectively. The WEE extract was found to be an effective bovine carbonic anhydrase (BCA) and α-glucosidase inhibitor with an IC50 values of 0.0628 and 0.0535 mg/mL, respectively. The EE extract showed activity against both Gram-negative and Gram-positive bacteria used in the study. EE extract has the highest activity against Yersinia pseudotuberculosis and the lowest activity against Streptococcus pyogenes. Furthermore, the extracts significantly reduced the biofilm ability of Acinetobacter baumannii isolate, which has strong biofilm ability. EE and WE reduced the biofilm formation capacity of the strain to a weak level, while WEE extract reduced it to a moderate level. The results suggest that EE has a significant effect in combating antibiotic resistance, while WEE has high antioxidant activity and good inhibitory effect against BCA and α-glycosidase enzymes. In addition, the results revealed that solvent extracts with different solvent composition and polarity may have different effects on diverse bioactivity tests.
- MakaleAçık Erişim2025DYE REMOVAL PERFORMANCE AND BIOLOGICAL ACTIVITIES OF IRON OXIDE NANOPARTICLES SYNTHESIZED FROM Cotoneaster sp. FRUIT EXTRACT
Akar, Bülent; Baltacı, Cemalettin; Düzgün, Azer Özad; Karpuz, Omer; Karakullukçu, Volkan; Erdoğdu, Esma Gülbahar
This work aimed to study the antioxidant, antibacterial, and dye adsorption capabilities of the aqueous extract of Cotoneaster sp. fruits (CFE) and iron oxide nanoparticles (CF-FeONP) green-synthesized from the CFE. CF-FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The antioxidant activity of CFE and CF-FeONPs was assessed through various tests, including ABTS radical scavenging activity, DPPH radical scavenging activity, iron-reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant content (TAC). The CF-FeONPs had superior antibacterial and antioxidant activity compared to the CFEs. Furthermore, CF-FeONPs suppressed the growth of Gram-negative bacteria such as Yersinia pseudotuberculosis ATCC 911, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, and Pseudomonas aeruginosa ATCC 43288, as well as by Gram-positive bacteria like Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923. and Bacillus subtilis ATCC 6633. The microdilution medium technique was used to determine the minimum inhibitory concentration (MIC) of CFE and CF-FeONPs against these bacteria strains. The adsorption rates of CF-FeONPs exhibited variability based on the quantity of adsorbent used and the specific dye type, whereas the lowest adsorption rate was 250 mg/L. CF-FeONPs demonstrated higher adsorption capacities for malachite green (MG) dye compared to methylene blue (MB) and phenol red (PR).
- MakaleAçık Erişim2024Investigation of antibiofilm and biological activities of Vaccinium arctostaphylos L.
Düzgün, Azer Özad; Akar, Zeynep; Kardil, Ugur
This study investigated the total phenolic and flavonoid contents and the antioxidant, antimicrobial, antibiofilm and α-glucosidase inhibitory activities of methanol extract from Vaccinium arctostaphylos L. leaf and fruit parts. The highest antioxidant activity with 53 µM TEAC and 0.0084 mg/mL SC50 using the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, respectively determined in leaf part. The data indicated that the leaf of the plant had the higher total phenolic content (49 µg/mL GAE) and total flavonoid content (0.071 µg/mL QAE) compared to fruit. The α-glucosidase enzyme activity of the leaves (0.179 mg/mL IC₅₀) was observed to be higher than that of the fruits (0.386 mg/mL IC₅₀). The MIC values of the leaf and fruit parts of blueberry were 6.25 mg/ml and 3.125 mg/ml, respectively. The results of this study indicate that the leaf extract was found to significantly reduce the biofilm-forming capacity of the Acinetobacter baumannii isolate by approximately 3-fold, whereas the fruit extract was observed to have only a marginal effect, reducing the biofilm-forming capacity by approximately 1.4-fold. The effects of plant extracts on microbial biofilms may be examined with a view to combating antibiotic resistance. Also results suggesting that it might be an effective and safety medical plant to prevent or treat diseases associated with oxidative damage and bacterial infections. Consequently, further research on natural substances may lead to the development of treatment options.
- MakaleAçık Erişim2024Vitis Labrusca L. Kabuk Ekstraktlarının Antibiyofilm, Antidiyabetik ve Antioksidan Potansiyelleri
Düzgün, Azer Özad; Akar, Zeynep; Kardil, Ugur
Bu çalışmada, Vitis labrusca L. bitkisinin kabuk kısımlarından elde edilen metanol, 50:50% metanol:su ve su ekstraktlarının antioksidan, antimikrobiyal, antibiyofilm ve α-glukozidaz inhibitör aktiviteleri ile toplam fenolik ve flavonoid içerikleri incelenmiştir. 50:50% metanol:su özütü, sırasıyla FRAP ve DPPH• radikal süpürücü analizleriyle belirlendiği üzere, 153 μM TEAC ve 0,0947 mg/mL SC50 ile en yüksek antioksidan aktiviteyi sergilemiştir. 50:50% metanol:su ekstraktı, sırasıyla 141 μg/mL GAE ve 0,103 mg/mL IC₅₀ değeri ile diğer çözücü ekstraktları arasında en yüksek toplam fenolik içeriği ve α-glukozidaz enzim inhibisyonunu sergilemiştir. Metanol, su ve 50:50% metanol:su ekstraktlarının MİK değerleri, klinik antibiyotik direnci olan Acinetobacter baumanii' ye karşı sırasıyla 6.25, 25 ve 12.5 mg/mL olarak belirlenmiştir. Metanol, su ve %50:50 metanol:su ekstraktlarının Acinetobacter baumannii izolatının biyofilm oluşturma kapasitesini sırasıyla yaklaşık 1.7, 1.6 ve 1.3 kat azalttığı bulunmuştur. Bulgular, 50:50% metanol:su ekstraktının en yüksek fenolik içerik, antioksidan aktivite ve α-glukozidaz inhibisyonu sergilediğini, metanol ekstraktının ise en belirgin antimikrobiyal ve antibiyofilm aktivitelerini gösterdiğini ortaya koymuştur. Araştırmamızın sonuçları, çeşitli çözücülerin ve bunların ilgili bileşimlerinin kullanımının biyolojik aktivitede önemli farklılıklar yaratma kapasitesine sahip olduğunu göstermektedir. Bu durum, V. labrusca kabuk bileşenlerinin oksidatif stres ve bakteriyel enfeksiyonlarla ilgili rahatsızlıkların ele alınmasında değerli bir yol olarak hizmet etme potansiyeline işaret etmektedir.
- MakaleAçık Erişim2024Effect of Different Storage Conditions and Infusion Times on Antioxidant and Antimicrobial Activites and Total Phenolic Content of Rosehip Fruits
Düzgün, Azer Özad; Acet, Tuba; Baltaci, Cemalettin; Akmeşe, Osman; Ural, Mustafa Nuri; Akar, Zeynep; Darak, Münevver; Kılınç, Kagan
Rosa canina L. (Rosehip) is a medicinal plant with strong antioxidant properties.The content of rosehip and accordingly its antioxidant capability may vary according to the way the fruits are used, storage, infusion, freezing and drying methods. In study, it was aimed to determine the antioxidant, antimicrobial activities in rosehip infusion products and extracts under these conditions. Fresh, frozen, dried and +40C stored fruits were infused at 90 degrees and infusion groups were formed. During infusion, samples were taken at 30, 60, 90, 120, 300 and 360th minutes and antioxidant activity (DPPH, FRAP and ABTS methods), total phenolic and total flavonoid contents (TPC and TFC), and antimicrobial activity were analyzed. In addition, phenolic compound content was investigated in 3 different extracts by HPLC method. Dried rosehip (DR) infusing samples were found to have the highest antioxidant activity, TPC and TFC compared to all groups (p-value ranged between 0.000 and 0.05).). Significant decreases were detected in the parameters according to storage and freezing times. A total of 8 phenolic compounds, the highest concentration of which was epicatechin, were detected in aqueous and ethanolic extracts of dried and stored at 40C rosehip (DR+40C) and dried rosehip (DR) fruits. For antimicrobial analysis, Total 7 different Gram (+) and (Gram (-) bacterial strains, were used. While antimicrobial activity was observed in the extracts, no activity was observed in the infusion products. It was determined that antioxidant activity increased during 360 minute infusion time, although it varied according to storage conditions.
- MakaleAçık Erişim2023Trabzon Fatih Devlet Hastanesinden İzole Edilen Klinik Acinetobacter baumannii ve Pseudomonas aeruginosa Suşlarında Antibiyotik Direnç Genlerinin Araştırılması
Sarıyer, Aysegül Saral; Düzgün, Azer Özad; Akyildiz, Esma; Köse, Tuba; Beris, Fatih Saban
Bu çalışmanın amacı Acinetobacter baumannii ve Pseudomonas aeruginosa izolatlarının antibiyotik duyarlılık profilini araştırmak ve bu izolatlarda direnç genlerinin varlığını belirlemektir. Direnç genlerinin tespiti PCR yöntemi ile değerlendirildi. Acinetobacter baumannii izolatlarında imipenem ve meropenem direnci sırasıyla %93,2 ve %91 olduğu görüldü. P. aeruginosa izolatlarında imipenem direnç oranı %53,9 ve meropenem direnç oranı %38,5 olarak belirlendi. Pseudomonas aeruginosa izolatları arasında aranan genlerden bir izolatta sadece OXA-23 tespit edildi. Acinetobacter baumannii izolatlarından bir izolatta OXA-24, 40 izolatta OXA-23 saptandı. Bu çalışma, CRPA (Karbapenem dirençli Pseudomonas aeruginosa) ve CRAB (Karbapenem dirençli Acinetobacter baumannii) izolatlarında karbapenem direncinden OXA-23'ün sorumlu olduğunu göstermektedir.
- MakaleAçık Erişim2023Characterization, Antioxidant and Antimicrobial Activities of Iron Nanoparticles Synthesized Using Firethorn Fruit (Pyracantha coccinea Roemer) Extracts
Düzgün, Azer Özad; Baltaci, Cemalettin; Akar, Bülent; Karakullukçu, Volkan; Karpuz, Omer
The main focus of this study was to explore the biological activity of metal nanoparticles that were green-synthesized from firethorn fruits. Specifically, iron nanoparticles (Fe-NP) were synthesized from extracts obtained from fruits and seeds of the firethorn plant (Pyracantha coccinea) grown on Gumushane University’s campus for landscaping purposes. The antioxidant and antimicrobial properties of both extracts and synthesized iron nanoparticles were evaluated. To characterize the Fe-NPs, FT-IR spectroscopy, scanning electron microscopy (SEM), and X-Ray Diffraction (XRD) analyses were performed. The antioxidant activity of the fruit extracts and Fe-NPs was assessed using various antioxidant activity tests, including ABTS radical scavenging activity, DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant content (TAC). The results of all antioxidant activity tests indicated that the iron nanoparticles exhibited higher antioxidant activity than the fruit extracts. Moreover, the minimum inhibitory concentrations (MIC) of the fruit extracts and nanoparticles against Gram-negative bacteria (Yersinia pseudotuberculosis ATCC 911, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, and Pseudomonas aeruginosa ATCC 43288) and Gram-positive bacteria (Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923, and Bacillus subtilis ATCC 6633) were determined the using the medium microdilution procedure. Similar to the antioxidant activity findings, the Fe-NPs demonstrated stronger antimicrobial activity compared to the fruit extracts.
- MakaleAçık Erişim2021Antibiotic induced biofilm formation of novel multidrug resistant Acinetobacter baumannii ST2121 clone
Çimen, Müberra; Düzgün, Azer Özad
The aim of this study was to identify antimicrobial resistance and virulence factor genes exhibited by multidrug resistant (MDR) Acinetobacter baumannii, to analyze biofilm formation and to investigate clonal subtypes of isolate. Whole genome sequencing was done by Illumina NovaSeq 6,000 platform and multilocus sequence typing (MLST) was performed by Oxford and Pasteur typing schemes. Influence of imipenem and levofloxacin on biofilm formation was investigated in 96-well plates at 3 replicates. The strain was found to carry OXA-23, OXA-51-like, AmpC and TEM-1 beta-lactamases. The sequence of the blaOXA-51-like gene has been identified as a blaOXA-66. According to Pasteur MLST scheme the strain displayed ST2 allelic profile. However, based on Oxford MLST scheme this strain represents the new ST2121, as the gdhB gene has a single allelic mutation namely, the gdhB-227. It was determined that MDR isolate carried bap, basABCDFGHIJ, csuA/BABCDE, bauABCDEF, plcD, pgaABCD, entE, barAB, ompA, abaIR, piT2EAFTE/AUBl, fimADT, cvaC, bfmR, bfmS virulence genes. In our study imipenem induced the highest biofilm formation at a concentration of 32 mg/ml and levofloxacin at a concentration of 16 mg/ml. In conclusion, we detected a new MDR A. baumannii ST2121 clone harboring blaOXA-66 gene that has been reported for the first time in Turkey.
- MakaleAçık Erişim2021Investigation of class 1 integrons with antibiotic resistance genes in multidrug-resistant acinetobacter baumannii strains and determination of plant extract effects on multidrug-resistant isolates
Saral, Ayşegül; Cinemre, Sedanur; Okumuş, Funda; Akar, Zeynep; Çiçek, Ayşegül Çopur; Düzgün, Azer Özad
This study aimed to investigate the presence of resistance genes in multidrug-resistant A. baumannii isolates as well as to determine the antibacterial activity of selected plant extracts against isolates. 41 strains were isolated from various clinical samples. PCR tests were performed using the primers. Methanol was used as solvent for the preparation of the plant extracts. MIC values of the plant extracts were determined by the broth microdilution method. The blaOXA-23, blaCTX-M-1, blaCTX-M-2, blaGES genes and Class 1 integrons were detected in five isolated strains. The lowest MIC value (2.25 mg/mL) was determined for the Echinacea purpurea extract, while the highest MIC value (50 mg/mL) was determined for the Morus alba extract. Determination of the antibacterial effect of plants extracts used in the study against A. baumannii isolates shows the importance of screening the antibacterial activity of plants in the fight against antibiotic resistance.
- MakaleAçık Erişim2020Klinik E.coli İzolatlarında Virülans Faktör Genlerinin ve Genişlemiş Spektrumlu Beta Laktamazların Araştırılması
Sarıyer, Aysegül Saral; Düzgün, Azer Özad; Akyildiz, Esma; Köse, Tuba
Bu çalışmanın amacı, 83 klinik E.coli izolatında pap, hly, cnf, sfa, aer ve afa virulans genlerinin ve genişlemişspektrumlu beta laktamaz direnç genlerinin varlığını araştırmaktır. Antibiyotik duyarlılık testi için 17 farklı antibiyotikkullanılmıştır. 83 E. coli izolatında sfa, pap, hly, cnf, aer ve afa virülans genleri ve TEM, SHV, CTX-M1 ve CTX-M9genişlemiş spektrumlu beta laktamaz genleri polimer zincir reaksiyon (PZR) metodu ile araştırılmıştır. 83 izolatın,sefiksim, trimethoprim/sulfametaksazol, piperasilin/tazobaktam, amoksisilin/klavulanik asit, ampisilin, seftriakson,sefuroksim, sefuroksim aksetil, siprofloksasin, fosfomisin, gentamisin ve seftazidime karşı direnç oranları sırasıyla;%65, %54, %19, %38, %74, %75, %72, %75, %68, %2, %30, %49 olarak belirlenmiştir. CTX-M1, araştırılangenişlemiş spektrumlu beta-laktamaz (GSBL) genleri arasında 83 suşun 51’inde belirlenmesiyle en sık görülen GSBLolmuştur. TEM tipi beta laktamaz 33 suşta, CTX-M9 ve SHV 1 izolatta tespit edilmiştir. İzolatlarda en yaygın virülansgeni, 40 suşta tespit edilmesiyle aer geni, bunu izolatların 15’inde tespit edilen cnf geni takip etmiştir. Sfa, pap, afa vehly virulans genleri sırasıyla izolatların %15.6’sında, %15.6’sında, %9.6’sında ve %12.04’ünde görülmüştür. Ayrıca 83E.coli izolatında on farklı virulans faktör gen paterni tespit edilmiştir. Virulans gen kombinasyonları, 27 suşta aer, 6suşta cnf-sfa-pap, 1 suşta aer-pap, 2 suşta aer-afa, 6 suşta afa, 3 suşta sfa, 9 suşta aer-cnf-hly, 4 suşta sfa-pap, 1 suştahly-pap ve 1 suşta pap olarak gözlemlenmiştir. Sonuç olarak, İYE ile ilişkili bakteriyel patojenitenin araştırılması dahaiyi bir tıbbi müdahaleye katkı sağlayacaktır.
- MakaleAçık Erişim2019Antibacterial Activity of DMSO Extracts of Selected Plants Against Antibiotic Resistant Clinical Isolates
Düzgün, Azer Özad; Saral, Ayşegül; Kardil, Uğur
In this study, we aimed to find out new herbal materials that are able to inhibit the growth of the P. aeruginosaand E.coli clinical isolates that has antibiotic resistance. Clinical isolates used in this research are E. coli (n=1)and P.aeruginosa (n=1). Antibiotic susceptibility profiles of E. coli and P. aeruginosa were determined usinge-test. Plants were collected in Trabzon region of Turkey are Calendula officinalis, Hypericum perforatum andGlycyrrhiza glabra. DMSO were used as solvent and solid-liquid extraction was employed. Micro-dilutionmethod was preferred fo the determination of the minimum inhibitory concentration (MIC). MIC results wereobtained through observation of turbidities. According to E-test results, while P. aeruginosa was resistant topiperacillin, piperacillin/tazobactam, meropenem and ceftazidime, E. coli was resistant to piperacillin,cefotaxime and ceftazidime. DMSO extract of Calendula officinalis showed very strong activity against PA1with the best MIC (5 mg/mL). DMSO extract of three plant had lower MIC values (5-10 mg/ml) for EC1 andPA1 than ampicillin. In future studies antibacterial activity of different solvents extracts of these plants andother plants against antibiotic resistant clinical isolates will be examined. Natural products from plants arepromising in fighting with antibiotic-resistant bacteria.
- MakaleAçık Erişim2018Investigation of Antibiotic Resistance Genes and Class 1 Integron in Multi-Drug Resistant P. aeruginosa and E. coli Strains
Sarıyer, Aysegül Saral; Düzgün, Azer Özad
P. aeruginosa and E. coli are resistant to many antibiotics, so the treatment of infections of these pathogens has become difficult. Therefore, searching for the presence of antibiotic resistance genes in clinical isolates is of great importance. The purpose of this study is to investigate the presence of beta-lactam resistance genes and class 1 integron in multi-drug resistant P. aeruginosa and E. coli clinical strains. Vitek 2 Compact automatization system were used for identification and antibiogram of 2 P. aeruginosa and 2 E. coli isolates which were isolated from blood, urine and sputum specimens of patients whom were hospitalized in Gümüşhane State Hospital intensive care unit. Total DNA isolation was done by boiling DNA method. PCR were performed using primers of class 1 integron gene cassette, blaVIM, blaNDM, blaIMP, blaGES, blaCTXM-1, blaCTXM-2, blaOXA-58, blaOXA-23, blaOXA-51, blaOXA-40 and blaKPC. All amplification samples were performed on 1% agarose gel and subsequently visualized under UV light. According to the results of the antibiogram, P. aeruginosa isolates showed resistance against all used antibiotics except gentamicin. The E. coli isolates were found to be resistant to cephalosporin antibiotics and susceptible to carbapenems. blaCTXM-1-class A beta lactamase genes was found in 3 strains of 4, while no blaCTXM-2, blaGES and blaKPC genes were detected in the strains. The presence of the investigated class B and class D beta lactamase genes was not observed in any sample. The presence of class 1 integron was detected in 3 strains. According to the result of the DNA sequence analysis, it was determined that three integron positive samples had the dfrA1/AadA5 gene cassettes.
- MakaleAçık Erişim2018Next-generation sequencing of plasmid carrying blaOXA-48 in Klebsiella pneumoniae from Turkey
Düzgün, Azer Özad; Saral, Ayşegül
A carbapenem-resistant Klebsiella pneumoniae strain was isolated in Turkey in 2012 and blaNDM-1 and blaOXA-48 genes were observed in this strain. The aim of this study was to investigate transferability of plasmid bearing blaOXA-48 in K. pneumoniae and to use whole-genome sequencing in order to understand the genetic context of plasmid. K. pneumoniae strain was used as donor in conjugation experiments. Antibiotic susceptibility profile of selected transconjugant was determined. Plasmid was isolated from transconjugant colony and was named as pKPT. Complete sequencing of the pKPT was conducted using a next-generation sequencing. Annotation of the contigs was performed using the Geneious R9, followed by finding open reading frames (ORFs) with selected web-based tools. BLAST analysis was performed at the NCBI BLAST server to determine genes showing more than 90% similarity with these ORFs. Results of antibiotic susceptibility test showed that transconjugant colony was resistant to ampicillin/ sulbactam, piperacillin, and piperacillin/tazobactam. The pKPT plasmid had a length of 45,217 bp and an average G + C content of 49%. Blast analysis revealed that pKPT was included in the IncL/M incompatibility group. The pKPT was found to contain blaOXA-48 within Tn1999.2 transposon without any other antibiotic resistance gene.
- MakaleAçık Erişim2018Effect of amino acid substitution in New Delhi metallo-β-lactamase on carbapenem susceptibility
Düzgün, Azer Özad
The aim of this work was investigation of clinically important amino acid substitutions of NDM-1 variants. A blaNDM-1 gene was cloned into expression vector pET100/D-TOPO. The sequence of NDM-1 variants with substituted amino acids was determined by ClustalW program. A pET100/D-TOPO + blaNDM-1 was used to generate the alanine mutations at different positions, such as NDM-2 (P28A), NDM-3 (D95A), NDM-4 (M154A), NDM-5 (V88A), NDM-7 (D130A), and NDM-9 (E152A). The mutant variants were transformed into Escherichia coli DH5α. Changes in the activities of alanine mutation variants were determined by E-test. All samples had 32 μg/ml MIC values against ampicillin. The 28th amino acid mutation sample had the highest MIC value against ceftazidime, whereas decreased MIC value for piperacillin. It was observed that the resistance to imipenem was increased in mutant variants D95A, M154A, D130A, and E152A, comparing with P28A and V88A. It was found that NDM-1 has 0.64 μg/ml and the 130th amino acid mutation sample has 0.75 μg/ml meropenem MIC value.
- Editöre MektupAçık Erişim2016A novel integron gene cassette harboring VIM-38 metallo-β-lactamase in a clinical pseudomonas aeruginosa isolate
Beriş, Fatih Şaban; Akyildiz, Esma; Düzgün, Azer Özad; Coşkun, Umut Safiye Say; Sandalli, Cemal; Çiçek, Ayşegül Çopur
- MakaleAçık Erişim2013Detection of class 1 integron in Acinetobacter baumannii isolates collected from nine hospitals in Turkey
ÇIÇek, Ayşegül Çopur; Düzgün, Azer Özad; Saral, Ayşegül; Kayman, Tuba; ÇIzmecI, Zeynep; Balci, Pervin Özlem; Dal, Tuba; Firat, Mehmet; Tosun, Ismail; Alitntop, Yasemin Ay
Objective: To investigate the antibiotic resistance genes inserted into class 1 and class 2 integrons in Acinetobacter baumannii (A. baumannii) isolates obtained from nine different cities in Turkey. Methods: A collection of 281 A. baumannii clinical isolates were collected from nine diferent state hospitals in Turkey and were confirmed as A. baumannii by conventional biochemical, API testing and bla-OXA-51 specific PCR. The isolates were examined by PCR for existence of class 1 and 2 integron gene cassettes. Results: They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin (90.03%), ciprofloxacin (87.54%), cefepime and trimethoprim/sulfamethoxazole (81.13%). The lowest resistance rates was for cefotaxime (3.55%). class I integrons were detected in 6.4% (18/281) of A. baumannii strains and no class 2 integron was detected. The gene cassettes of class 1 integrons AacC1-AAC(3) I-aadA1, AacC1-aadA1, AAC(3)-I, AAC(3)-I -AAC(3)-I -aadA1, TEM-1, AAC(3)-I-aadA1 - AAC(3)-I -AAC(3)-I, AAC(3)-I -AAC(3)-I -AAC(3)-I -aadA1, AAC(3)-I - aadA1, AAC(3)-I-AAC(3)-I, AAC(3)-I-aadA1-AAC(3)-I-aadA1, AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains. The aac genes family were most frequently found integrated into the class 1 integrons and it was followed by aadA genes and TEM-1 genes. Conclusions: This is an extensive study on the distribution of class 1 integron among A. baumannii in Turkey. In addition to these, two new alleles were observed. Their percentage rates of similarity to other cassettes are 95% aadA1 (TKA18) and 89% aadA1 (ANKA3).