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Permanent URI for this collectionhttps://hdl.handle.net/11443/932

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Author: search.filters.author.Akyar, IsinHas files: Yes

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    MixInYeast: A Multicenter Study on Mixed Yeast Infections
    (MDPI, 2021-01-01) Medina, Narda; Soto-Debran, Juan Carlos; Seidel, Danila; Akyar, Isin; Badali, Hamid; Barac, Aleksandra; Bretagne, Stephane; Cag, Yasemin; Cassagne, Carole; Castro, Carmen; Chakrabarti, Arunaloke; Dannaoui, Eric; Cardozo, Celia; Garcia-Rodriguez, Julio; Guitard, Juliette; Hamal, Petr; Hoenigl, Martin; Jagielski, Tomasz; Khodavaisy, Sadegh; Lo Cascio, Giuliana; Martinez-Rubio, Maria Carmen; Meletiadis, Joseph; Munoz, Patricia; Ochman, Elzbieta; Pelaez, Teresa; Perez-Ayala Balzola, Ana; Prattes, Juergen; Roilides, Emmanuel; Ruiz-Perez de Pipaon, Maite; Stauf, Raphael; Steinmann, Joerg; Suarez-Barrenechea, Ana Isabel; Tejero, Rocio; Trovato, Laura; Vinuela, Lourdes; Wongsuk, Thanwa; Zak, Iwona; Zarrinfar, Hossein; Lass-Florl, Cornelia; Arikan-Akdagli, Sevtap; Alastruey-Izquierdo, Ana
    Invasive candidiasis remains one of the most prevalent systemic mycoses, and several studies have documented the presence of mixed yeast (MY) infections. Here, we describe the epidemiology, clinical, and microbiological characteristics of MY infections causing invasive candidiasis in a multicenter prospective study. Thirty-four centers from 14 countries participated. Samples were collected in each center between April to September 2018, and they were sent to a reference center to confirm identification by sequencing methods and to perform antifungal susceptibility testing, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). A total of 6895 yeast cultures were identified and MY occurred in 150 cases (2.2\%). Europe accounted for the highest number of centers, with an overall MY rate of 4.2\% (118 out of 2840 yeast cultures). Of 122 MY cases, the most frequent combinations were Candida albicans/C. glabrata (42, 34.4\%), C. albicans/C. parapsilosis (17, 14\%), and C. glabrata/C. tropicalis (8, 6.5\%). All Candida isolates were susceptible to amphotericin B, 6.4\% were fluconazole-resistant, and two isolates (1.6\%) were echinocandin-resistant. Accurate identification of the species involved in MY infections is essential to guide treatment decisions.
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    Evaluation of the performance of MALDI-TOF MS and DNA sequence analysis in the identification of mycobacteria species
    (TUBITAK SCIENTIFIC \& TECHNICAL RESEARCH COUNCIL TURKEY, 2018-01-01) Akyar, Isin; Cavusoglu, Cengiz; Ayas, Meltem; Surucuoglu, Suheyla; Ilki, Arzu; Kaya, Deniz Ece; Besli, Yesim
    Background/aim: Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry is an alternative way of identifying mycobacteria via the analysis of biomolecules. It is being increasingly used in routine microbiology practice since it permits early, rapid, and cost-effective identification of pathogens of clinical importance. In this study, we aimed to evaluate the efficacy of phenotypic identification of mycobacteria by the MALDI-TOF MS MBT Mycobacteria Library (ML) 4.0 (Bruker, Daltonics) compared to standard sequence analysis. Materials and methods: A total of 155 Mycobacterium clinical and external quality control isolates, comprising nontuberculous mycobacteria (NTM) (n = 95) and the Mycobacterium tuberculosis complex (MTC) (n = 60), were included in the study. Results: Identification by MBT ML4.0 was correctly performed in 100\% of MTC and in 91\% of NTM isolates. All of the MTC isolates were correctly differentiated from NTM isolates. Conclusion: Based on our results, MBT ML4.0 may be used reliably to identify both NTM and MTC.
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    Antimicrobial Susceptibility Test for the Determination of Resistant and Susceptible S. aureus and Enterococcus spp. Using a Multi-Channel Surface Plasmon Resonance Device
    (MDPI, 2019-01-01) Ucak Ozkaya, Gulsum; Durak, Muhammed Zeki; Akyar, Isin; Karatuna, Onur
    The objective of this study was to investigate the development of a surface plasmon resonance (SPR) sensor platform equipped with multiple channels for the simultaneous determination of methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA) and vancomycin-resistant Enterococcus (VRE), and vancomycin-susceptible Enterococcus (VSE). Drug resistance of S. aureus strains against cefoxitin and Enterococcus strains against vancomycin were investigated both using the minimum inhibitory concentration method (MIC) assay and the SPR system equipped with single and multiple channels. The MIC values of MRSA and MSSA ranged from 32 mu g/mL to >128 mu g/mL and from 1 mu g/mL to 4 mu g/mL, respectively. The MIC values of VRE and VSE were between 64 to >128 mu g/mL and 2-4 mu g/mL, respectively. With the multiple-channel system, the angle shifts of MRSA, MSSA, VRE and VSE were found to be -0.030 degrees and -0.260 degrees, -0.010 degrees and -0.090 degrees respectively. The antibiotic-resistant and susceptible strains were distinguished within 3 h for S. aureus strains and within 6 h for Enterococcus strains.
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    Rapid identification of Aeromonas species in stool samples with chromogenic media and matrix-assisted laser desorption ionization-time of flight mass spectrometry: an institutional experience
    (TUBITAK SCIENTIFIC \& TECHNICAL RESEARCH COUNCIL TURKEY, 2013-01-01) Akyar, Isin; Can, Simge
    Aim: To evaluate the routine use of chromogenic media together with matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF) in gastrointestinal infections caused by Aeromonas spp. as rapid, practical, cost-effective and reliable methods. Materials and methods: Between August 2007 and March 2012, a total of 13,194 stool specimens of patients were included in the study. The stool samples and the reference strains were inoculated onto Cefsulodin-Irgasan-Novobiocin agar, sheep blood agar, eosin-methylene blue agar, and Hektoen enteric agar media together with CHROMagar Salmonella Plus. All the Salmonella and Aeromonas suspected colonies were identified with an automated system (Phoenix) and MALDI-TOF. Results: Some of the pink colonies resembling Salmonella were identified as Aeromonas spp. without any discordance (100\%) between the systems. A total of 86 Aeromonas strains were identified: 30 A. caviae, 27 A. hydrophila, 16 A. veronii, 11 A. sobria, and 2 A. salmonicida. When analyzed macroscopically, those Aeromonas species had prominent colony appearance differences from classically detected Salmonella on CHROMagar Salmonella Plus media. Conclusion: A combination of CHROMagar Salmonella Plus and MALDI-TOF will help to detect Aeromonas species in 24 h in a cost-effective, practical, and reliable manner.