Browsing by Author "Akyar, Isin"

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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.
Determination of Antimony Resistance Mechanism of Leishmania tropica Causing Cutaneous Leishmaniasis in Turkey
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Zeyrek, Fadile Yildiz; Guray, Melda Zeynep; Culha, Gulnaz; Akyar, Isin; Harman, Mehmet; Ozbel, Yusuf; Ertabaklar, Hatice; Cavus, Ibrahim; Gunduz, Cumhur
World Health Organization reported that approximately one billion people are at risk in endemic areas, one million cases of cutaneous leishmaniasis (CL) and approximately 300,000 cases of visceral leishmaniasis (VL) were reported per year in the last five years. The number of deaths due to VL is reported to be approximately 20,000 per year. Approximately 2500 cases/year have been reported as CL, caused by Leishmania tropica and Leishmania infantum, in Turkey. The significant increase observed in many cities mainly in the provinces of Mediterranean and Aegean regions in cases and foci in recent years, suggests that there may be an increase in this infections in the following years as well. In Turkey, the causative agent of CL is L.tropica and meglumine antimoniate is used in the treatment of CL. We aimed to determine antimony resistance genes specific for L.tropica by comparing the gene and protein expressions of antimony-resistant and non-resistant L.tropica strains. Ltropica isolates obtained from 3 CL patients without antimonate resistance from Aegean, Mediterranean and Southeastern regions of Turkey were provided to transform into 3 resistant isolates against meglumine antimony in the laboratory conditions. Gene expression alterations by microarray method
Diversity of Leishmania Strains Isolated from Cutaneous Leishmaniasis Patients in Turkey and its Reflection to Clinics in Mice Model
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Culha, Gulnaz; Guray, Melda Zeynep; Zeyrek, Fadile Yildiz; Akyar, Isin; Toz, Seray; Ural, Ipek Ostan; Kurt, Ozgur; Kocagoz, Tanil; Cavus, Ibrahim; Gunduz, Cumhur
Although asexual reproduction has been attributed to Leishmania species, genetic exchange has recently been demonstrated, which helped emerging of hybrid isolates. Situated on the crossroads between three continents, Leishmania hybrids may be present in Turkey. In Turkey, visceral leishmaniasis caused by Leishmania infantum is less common, while cutaneous leishmaniasis (CL) caused by Leishmania tropica and L.infantum could reach 2500 reported cases a year. Our aim was to investigate genetic variability of local Leishmania species and presence of hybrid Leishmania strains in Turkey. Twenty CL patients from Sanliurfa and Hatay, where only L.tropica and both L.tropica and L.infantum cause CL, respectively, were registered equally. All isolates were assessed with real-time polymerase chain reaction (Rt-PCR), isoenzyme analysis, gene sequencing, two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF/TOF-MS followed by in vivo analyses on mouse model. Identification of differentially expressed proteins was performed. These proteins were confirmed by sequence analysis. All isolates from Sanliurfa were found to be L.tropica which caused cutaneous infection in mice. However, one of 10 isolates from Hatay was found as Leishmania major which caused cutaneous infection. Five isolates were found as L.tropica with Rt-PCR and gene sequencing, one of which had one different protein from the reference L.tropica strain and caused cutaneous infection. Four of the five isolates had five different proteins compared to reference strain and caused both cutaneous and visceral infections. Remaining four isolates showed double melting curves in Rt-PCR, which were concordant with L.tropica and L.infantum. Their sequencing and isoenzyme analyses indicated them as L.infantum. They had six different proteins compared to reference L.infantum strain and caused cutaneous and visceral infections. It is concluded that the isolates with different proteins were hybrid Leishmania species. In the present study, outcomes of the proteomics, genomics, clinical manifestations and tissue tropism on animal models were evaluated together for the first time. In addition to L. tropica and L.infantum, L.major was identified as a causative agent for CL and hybrids of Linfantum/tropica were also shown to be present.
Dobrava Hantavirus Infection Complicated by Panhypopituitarism, Istanbul, Turkey, 2010
(CENTERS DISEASE CONTROL, 2012-01-01) Sariguzel, Nevin; Hofmann, Joerg; Canpolat, Alper Tunga; Turk, Ali; Ettinger, Jakob; Atmaca, Deniz; Akyar, Isin; Yucel, Serap; Arikan, Ender; Uyar, Yavuz; Caglayik, Dilek Y.; Kocagoz, Ayse Sesin; Kaya, Aysin; Kruger, Detlev H.
We identified Dobrava-Belgrade virus infection in Turkey (from a strain related to hantavirus strains from nearby countries) in a patient who had severe symptoms leading to panhypopituitarism, but no known risk for hantavirus. Our findings emphasize the need for increased awareness of hantaviruses in the region and assessment of symptomatic persons without known risk factors for infection.
Evaluation of the Carba NP Test for the Detection of Carbapenemase Activity in Bacteroides Species
(POLSKIE TOWARZYSTWO MIKROBIOLOGOW-POLISH SOCIETY OF MICROBIOLOGISTS, 2018-01-01) Akyar, Isin; Ayas, Meltem; Karatuna, Onur; Besli, Yesim
We evaluated the usefulness of the Carba NP test for rapid detection of carbapenemase activity in Bacteroides spp. The minimum inhibitory concentration (MIC) for imipenem was determined with gradient test strips, and cfiA gene was investigated by polymerase chain reaction for 27 clinical Bacteroides spp. isolates. Carba NP test was performed according to recommendations of the Clinical and Laboratory Standards Institute. Among three cfiA gene harboring clinical isolates, two imipenem resistant isolates were Carba NP test positive, while the imipenem intermediate isolate was negative. Our preliminary results suggest that the Carba NP test can be useful as a rapid test to detect carbapenemases in Bacteroides species.
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.
Hepatitis C virus positive patient diagnosed after detection of atypical cryoglobulin
(BAISHIDENG PUBLISHING GROUP INC, 2016-01-01) Ongen, Belkiz; Aksungar, Fehime Benli; Cicek, Bahattin; Akyar, Isin; Coskun, Abdurrahman; Serteser, Mustafa; Unsal, Ibrahim
A 60-year-old male patient presented with jaundice and dark urine for three days, icteric sclerae and skin rash on his legs for six months. Laboratory inves-tigations revealed an atypical cryoglobulinemia with high hepatitis C virus (HCV)-RNA levels. Imaging studies showed cholestasis was accompanying HCV. Capillary zone electrophoresis using immunosubtraction method revealed a polyclonal immunoglobulin G and immunoglobulin A (IgA) monoclonal cryoglobulin and that IgA lambda was absent in immu-nofixation electrophoresis. After a liver biopsy, chronic hepatitis C, HCV related mixed cryoglobulinemia and cryoglobulinemic vasculitis were diagnosed and antiviral therapy was initiated. Our HCV patient presented with cryoglobulinemic symptoms with an atypical cryoglobulinemia that was detected by an alternative method: Immunosubtraction by capillary electrophoresis. Different types of cryoglobulins may therefore have a correlation with clinical symptoms and prognosis. Therefore, the accurate immunotyping of cryoglobulins with alternative methods may provide more information about cryoglobulin-generated pathology.
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.
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.
Six-year distribution pattern of hepatitis C virus in Turkey: a multicentre study
(TAYLOR \& FRANCIS LTD, 2016-01-01) Altindis, Mustafa; Dal, Tuba; Akyar, Isin; Karatuna, Onur; Gokahmetoglu, Selma; Ulger, Seda Tezcan; Kulah, Canan; Uzun, Berrin; Sener, Asli Gamze; Ozdemir, Mehmet; Aydogan, Sibel; Kuskucu, Mert Ahmet; Midilli, Kenan; Otlu, Baris; Celen, Mustafa Kemal; Buruk, Kurtulus; Guducuoglu, Huseyin
Hepatitis C infection is a public health problem. The aim of this retrospective study was to determine the distribution of hepatitis C virus (HCV) genotypes in seven regions of Turkey, by evaluating 7002 patients with chronic HCV in a six-year period. During the 2009-2014 period, serum/plasma samples from 7002 new consecutive HCV RNA positive patients were collected. The female patients were 3867 (55.2\%). The genotype distribution of HCV patiens was evaluated by ages and years. Statistical analysis was performed by using the Mann-Whitney test and the chi(2) analysis. During the six-year period, genotype 1b was the most common genotype (67.7\%) followed by untypeable genotype 1 (7.7\%), genotype 4 (7.3\%) and genotype 3 (6.7\%). In 2014, genotype 3 was the second most common one (11.3\%) and genotype 4 was the third most common one (9.8\%). In the group with <25 years old patients, genotype 1b was most common (78.48\%, 62/79) between the years of 2009 and 2011, whereas genotype 3 (34.8\%, 86/247), between the years of 2012 and 2014. Genotype 1b was the most common in the groups between 26 and 35 years, 36 and 45 years, 46 and 55 years, 56 and 65 years. The rate of genotype 3 was increased from 4.78\% to 10.06\% and the rate of genotype 4 was increased from 1.3\% to 3.84\%, from 2009-2011 to 2012-2014. In recent years, genotypes 3 and 4 have gained importance. New therapeutic strategies and survey studies may be required for the modified HCV genotype pattern.
The use of matrix-assisted laser desorption ionization-time of flight mass spectrometry in the identification of Francisella tularensis
(ASSOC BASIC MEDICAL SCI FEDERATION BOSNIA \& HERZEGOVINA SARAJEVO, 2016-01-01) Karatuna, Onur; Celebi, Bekir; Can, Simge; Akyar, Isin; Kilic, Selcuk
Francisella tularensis is the cause of the zoonotic disease tularemia and is classified among highly pathogenic bacteria (HPB) due to its low infection dose and potential for airborne transmission. In the case of HBP, there is a pressing need for rapid, accurate and reliable identification. Phenotypic identification of Francisella species is inappropriate for clinical microbiology laboratories because it is time-consuming, hazardous and subject to variable interpretation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was recently evaluated as a useful tool for the rapid identification of a variety of microorganisms. In this study, we evaluated the use of MALDI-TOF MS for the rapid identification of Francisella tularensis and differentiation of its subspecies. Using national collection of Francisella isolates from the National Tularemia Reference Laboratory (Public Health Institution of Turkey, Ankara), a total of 75 clinical isolates were investigated by species and subspecies-specific polymerase chain reaction (PCR) test and MALDI-TOF MS. All isolates were originally identified as F. tularensis subsp. holarctica according to region of difference 1 (RD1) subspecies-specific PCR results. For all isolates MALDI-TOF MS provided results in concordance with subspecies-specific PCR analysis. Although PCR-based methods are effective in identifying Francisella species, they are labor-intensive and take longer periods of time to obtain the results when compared with MALDI-TOF MS. MALDI-TOF MS appeared to be a rapid, reliable and cost-effective identification technique for Francisella spp. Shorter analysis time and low cost make this an appealing new option in microbiology laboratories.