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Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/gumushane/13536
  Cloning and biochemical characterization of a novel GH1 β-glucosidase from thermophilic bacterium, Anoxybacillus flavithermus DSM 2641T

  Akgeyik, Aytul Uzun; Akyildiz, Esma; Karaoglu, Hakan; Beris, Fatih Saban

  β-glucosidases belong to the class of glycoside hydrolases (GHs) and can mediate the cleavage of β-1-4 glycosidic bonds in alkyl or aryl-β-D-glucosides, amino, cyanogenic glucosides, and oligo-or disaccharides. The gene encoding β-glucosidase of Anoxybacillus flavithermus DSM2641T was subcloned and expressed in E. coli BL21 Star(DE3) cells with pET100 Directional TOPO Expression Kit. The recombinant AFBGL was purified by a Ni-NTA affinity chromatography. The enzyme was 53 kDa and had 5.13 × 105 µmol/min/mg protein of Vmax and 422.3 µM of Km towards p-nitrophenyl β-D-glucoside as a main substrate. The optimum temperature and pH of the purified enzyme were 65°C and 6.8, respectively. We also determined kinetic parameters of AFBGL against the other artificial substrats, pNPC, pNPX, and oNPG. The enzyme had the Vmax and Km for 5.13 × 105 µmol/min/mg protein and 0.42 mM for pNPG, 0.007 µmol/min/mg protein and 0.19 mM for pNPC, 0.01 µmol/min/mg protein and 11.97 mM for pNPX, 0.06 µmol/min/mg protein and 0.134 mM for oNPG, respectively. AFBGL's substrate affinity was found to be more directed towards oNPG. Although 0.5 mM Mg2+ increases the enzyme's activity 1.6-fold, higher concentrations of Mg2+ and the presence of K+, Fe2+, Mn2+, Zn2+, Cu2+, and Al3+ decreases its activity. AFBGL retained 50% of the initial activity towards pNPG for 25 min and the activity was not detected after 225 min. According to amino acid motifs, AFBGL belongs to family 1 of glycosylhydrolase and 4/7 super family. So, AFBGL is a member of GH1, as the amino acid sequence contained a GH1 specific domain.

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• MakaleAçık Erişim2023/r/gumushane/20400
  Trabzon 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.

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• MakaleAçık Erişim2023/r/gumushane/11943
  First report of qnr and blaVIM-4-like producing clinical Alcaligenes faecalis isolated in Türkiye; [Türkiye'den izole edilen qnr ve blaVIM-4-like üreten klinik Alcaligenes faecalis’in ilk raporu]

  Akyildiz, Esma; Saral Sariyer, Ayşegül; Köse, Tuba; Arslan, Mikail; Beriş, Fatih Şaban; Özad Düzgün, Azer

  The study set out to look at the clinical strain of A. faecalis's antibiotic susceptibility pattern. Both biochemical and molecular approaches were used to identify A.faecalis. The VITEK compact system was used to analyze the strain's antibiotic susceptibility profile. The use of PCR was evaluated to determine the presence of resistance genes. It was also determined whether resistance determinants could be transferred. It was determined that A. feacalis showed resistance to imipenem, cefepime, ceftazidime, gentamicin, amikacin, netilmicin, tobramicin, ciprofloxacin, and levofloxacin. The blaVIM-4-like gene was present in this strain, according to the results of the PCR and DNA sequencing studies. In contrast to VIM-4, this blaVIM-4-like gene showed one amino acid change (Ala265Val).Filter-mating experiments showed that the blaVIM-4-like gene cannot be transferred from A. faecalis to E. coli. In this study, This research, demonstrated the presence of the blaVIM-4-like gene for the first time in A. faecalis from Turkey.

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  İncele
• MakaleYalnız künye2022/r/gumushane/11796
  In vitro and in silico evaluation of some plant extracts and phytocompounds against multidrug-resistant Gram-negative bacteria

  Aydemir, Eda; Sarıyer, Emrah; Akyıldız, Esma; Özad Düzgün, Azer; Camadan, Yasemin; Saral Sarıyer, Ayşegül

  The spread of multidrug-resistant Gram-negative (MDR) bacteria is a global public health problem, as infections caused by MDR Gram-negative bacteria are difficult to treat. New antibiotic agents need to be developed to overcome this problem, and phytochemicals show promise at this point. In this study, methanol extracts were prepared from cinnamon, thyme, nettle, white tea, rosehip, and antibacterial activity of the methanol extracts was studied against two MDR Gram-Negative bacteria (K. pneumoniae and A. baumannii) by broth microdilution method. The MICs of methanol extracts of cinnamon, rosehip, thyme, white tea for A. baumannii were found as 0.015125 g/ml, 0.07825 g/ml, 0.030625 g/ml, 0.00796875 g/ml, respectively. It was found that only cinnamon methanol extract had antibacterial activity in the used extract concentrations against K. pneumoniae and the MIC value was 0.0605 g/ml. The effects of plant methanol extract with antibacterial activity and imipenem combinations were studied in vitro using the checkerboard method. The FIC Indexes were obtained from the checkerboard results and it was observed that the combination of methanol extract and imipenem showed an antagonistic or additive/indifferent effect but not a synergistic effect. We evaluated the binding affinity of epigallocatechin 3-gallate, quercetin, cinnamaldehyde, carvacrol, and thymol phytocompounds using in silico methods, which are well known as a phytocompounds in white tea, cinnamon, thyme, nettle, and rosehip and have antibacterial activities. The results suggested that these phytocompounds should be supported with in vivo and in vitro experiments to investigate their potential for being inhibitor candidates.

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  İncele
• MakaleAçık Erişim2020/r/gumushane/17875
  Klinik 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.

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  İncele
• Editöre MektupAçık Erişim2016/r/gumushane/12953
  A 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

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