Sürdürülebilir Kalkınma Amaçları
Yayınlar
- 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 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 Erişim2019Determination of antibiotic resistance genes and virulence factors in Escherichia coli isolated from Turkish patients with urinary tract infection
Özad Düzgün, Azer; Okumuş, Funda; Saral, Ayşegül; Çopur Çiçek, Ayşegül; Cinemre, Sedanur
Introduction: Escherichia coli ranks among the most common sources of urinary tract infections (UTI). Methods: Between November 2015 and August 2016, 90 isolates of E. coli were isolated from patients at Rize Education and Research Hospital in Turkey. Antibiotic susceptibility was determined for all isolates using the Kirby-Bauer disk diffusion method. These E. coli isolates were also screened for virulence genes, β-lactamase coding genes, quinolone resistance genes, and class 1 integrons by PCR. Results: With respect to the antibiotic resistance profile, imipenem and meropenem were effective against 98% and 90% of isolates, respectively. A high percentage of the isolates showed resistance against β lactam/β lactamase inhibitor combinations, quinolones, and cephalosporins. PCR results revealed that 63% (57/90) of the strains carried class 1 integrons. In addition, a high predominance of extended-spectrum β-lactamases (ESBLs) was observed. The qnrA, qnrB, and qnrS genes were found in 24 (26.6%), 6 (6.6%), and 3 (3.3%), isolates, respectively. The most common virulence gene was fim (82.2%).The afa, hly, and cnf1 genes were detected in 16.6%, 16.6%, and 3.3% of isolates, respectively. Moreover, we observed eleven different virulence patterns in the 90 E. coli isolates. The most prevalent pattern was fim, while hly-fim, afa-aer-cnf-fim, aer-cnf, afa-aer, and afacnf- fim patterns were less common. Conclusions: Most of the E. coli virulence genes investigated in this study were observed in E. coli isolates from UTI patients. Virulence genes are very important for the establishment and maintenance of infection.
- 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 Erişim2016Comparison of verona integron-borne metallo-β-lactamase (VIM) variants reveals differences in stability and inhibition profiles
Makena, Anne; Düzgün, Azer Ö.; Brem, Jürgen; McDonough, Michael A.; Rydzik, Anna M.; Abboud, Martine I.; Saral, Ayşegül; Çiçek, Ayşegül Č.; Sandalli, Cemal; Schofield, Christopher J.
Metallo-β-lactamases (MBLs) are of increasing clinical significance; the development of clinically useful MBL inhibitors is challenged by the rapid evolution of variant MBLs. The Verona integron-borne metallo-β-lactamase (VIM) enzymes are among the most widely distributed MBLs, with>40 VIM variants having been reported. We report on the crystallographic analysis of VIM-5 and comparison of biochemical and biophysical properties of VIM-1, VIM-2, VIM-4, VIM-5, and VIM-38. Recombinant VIM variants were produced and purified, and their secondary structure and thermal stabilities were investigated by circular dichroism analyses. Steady-state kinetic analyses with a representative panel of β-lactam substrates were carried out to compare the catalytic efficiencies of the VIM variants. Furthermore, a set of metalloenzyme inhibitors were screened to compare their effects on the different VIM variants. The results reveal only small variations in the kinetic parameters of the VIM variants but substantial differences in their thermal stabilities and inhibition profiles. Overall, these results support the proposal that protein stability may be a factor in MBL evolution and highlight the importance of screening MBL variants during inhibitor development programs.
- 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).