Yazar "Bulut, Mehmet Emin" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    Detection of Hypervirulent ST-17 Clone Among Clinical Group B Streptococcus Isolates Using MALDI-TOF MS and PCR
    (Doc Design Informatics Co Ltd, 2025) Malkocoglu, Gulsah; Bulut, Mehmet Emin; Bayraktar, Banu; Otlu, Baris; Aktas, Elif
    Objective: Group B streptococcus (GBS) is the leading causative agent of neonatal morbidity and mortality. Sequence type 17 (ST-17) in GBS causes neonatal invasive disease more frequently than other STs. This study aimed to investigate the presence of hypervirulent ST-17 in a collection of clinical GBS isolates. Materials and Methods: GBS isolates obtained from patients with invasive and non-invasive infections were included in the study. For the detection of ST-17 GBS, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and polymerase chain reaction (PCR) methods were performed. Multilocus sequence typing (MLST) was also performed in a subset of some representative GBS strains. Results: Among 108 GBS isolates included in the study, 6 (5.5%) were identified as ST-17 by MALDI-TOF MS. Discriminatory peaks were detected at 7620 Da for ST-17 and 7638 Da for non-ST-17 isolates. In addition to six isolates that were positive for ST-17 by MALDI-TOF MS, one more isolate (GBS2) was found to be positive for ST-17 by PCR test. MLST revealed that those six isolates were ST-17 or single-locus variants of ST-17, while the isolate GBS2 was ST-1. Among the remaining 20 representative GBS isolates, 14 STs were identified by MLST, and all of them were non-ST-17 in accordance with MALDI-TOF MS and PCR results. Conclusion: In this study, the presence of a circulating hypervirulent ST-17 clone in T & uuml;rkiye was demonstrated for the first time. MALDI-TOF MS successfully and rapidly detected ST-17 and non-ST-17 GBS isolates. This practical method may contribute to efficiently managing neonatal infections caused by ST-17 GBS.
  • Küçük Resim Yok
    Öğe
    Evaluation of the Carbapenem Inactivation Method for Detection of Carbapenemase Producing Gram Negative Bacteria in Comparison with the RAPIDEC CARBA NP
    (Microbial Drug Resistance, 2016) Aktaş, Elif; Malkoçoğlu, Gülşah; Otlu, Barış; Çopur Çiçek, Ayşegül; Külah, Canan; Cömert, Füsun; Sandallı, Cemal; Gürsoy, Nafia Canan; Erdemir, Duygu; Bulut, Mehmet Emin
    Timely detection of carbapenemases by both phenotypic and genotypic methods is essential for developing strategies to control the spread of infections by carbapenem-resistant isolates and related morbidity and mortality. The aim of this study was to compare the performance of a commercial kit, the RAPIDEC® CARBA NP, and an in-house technique, the carbapenem inactivation method (CIM), against a panel of 136 carbapenemase- and noncarbapenemase-producing Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa isolates. RAPIDEC CARBA NP displayed 99% sensitivity and 100% specificity, whereas the sensitivity and specificity were 78% and 100% for the CIM test, respectively. A slight modification of the CIM test, a prolonged incubation time of 4 hours instead of two, increased the sensitivity of the test to 90% by diminishing false negativity particularly for A. baumannii. In conclusion, both tests possess a high performance and are practical for the detection of carbapenemases. Although RAPIDEC CARBA NP is a more rapid and reliable method, the CIM test may represent a useful tool for microbiology laboratories due to its simplicity and availability at any laboratory with low cost.
  • Küçük Resim Yok
    Öğe
    Urinary Salmonella Enteritidis Carriage in a Patient Living with
    (Ankara Microbiology Soc, 2025) Tutan, Hanife; Gul, Ozlem; Karaca, Hakan; Tanriverdi, Elif Seren; Bulut, Mehmet Emin; Aktas, Elif
    Non-typhoidal Salmonella (NTS), a major public health problem worldwide, frequently causes gastrointestinal infections and can develop asymptomatic carriage. Isolation of NTS in urine and urinary carriage, are extremely rare and theirfrequency increases in the presence of predisposing factors. In today's world where the rates of quinolone-resistant Salmonella spp. are rapidly increasing, the implementation of the correct treatment protocol, especially in patients in the risk group, is the most fundamental step to prevent the development of carriage. In this case report, an human immunodeficiency virus (HIV)- infected patient with urinary carriage of Salmonella Enteritidis was presented. A 59-year-old male patient applied to the outpatient clinic with dysuric complaints. He was being followed for HIV infection and was receiving appropriate antiretroviral therapy. He had coronary artery disease, hypertension, chronic renal failure and nephrolithiasis. Physical examination was normal without fever. Salmonella spp. grew in urine culture and S.Enteritidis was reported by serotyping. The susceptibility profile was determined as sensitive to ampicillin, ceftriaxone, cefotaxime and trimethoprim/sulfamethoxazole by disk diffusion and resistant to ciprofloxacin (MIC= 0.19 mg/L) by gradient test. Lower urinary tract infection (UTI) was considered and five-day cefixime treatment was started. The patient's complaints did not improve after treatment and S.Enteritidis was grown again in the culture. Salmonella spp. was not grown in the stool sample obtained from the patient who was learned to have gastroenteritis recently. The patient was treated with cefixime for two more weeks and there was no growth in the control culture. A few weeks later, urinary symptoms recurred and S.Enteritidis growth was again observed in urine culture and treatment was planned. Urological evaluation revealed bilateral multiple stones and cortical cysts and it was stated that operation was not possible. Twelve isolates determined from the urine cultures of the patient for 27 months were genotyped using AP-PCR and it was shown that all isolates were of the same genotype. During the patient's follow-up, bacteriuria persisted for 27 months whether the patient was symptomatic or asymptomatic and this was associated with HIV infection and underlying nephrolithiasis. The present case was considered as NTS-induced UTI after possible Salmonella gastroenteritis and asymptomatic urinary carriage during follow-up. When NTS-induced UTI is detected, patients should be evaluated for the presence of risk factors. Elimination of risk factors is critical to achieve complete cure and prevent carriage. Otherwise, even long-term antibiotic therapy may be inadequate. Increasing resistance rates to fluoroquinolones, one of the first choices for the treatment and decolonization of Salmonella infections, are alarming. In addition to rational drug use, it is important to carefully regulate policies on antimicrobial use in the agriculture and livestock sector, which have been shown to play a major role in the development of drug resistance. In addition, considering the number of people living with HIV, NTS infections should be kept in mind in the follow-up of these patients and patients should be monitored for carriage.
  • Küçük Resim Yok
    Öğe
    VIM-1, VIM-2, and GES-5 Carbapenemases Among Pseudomonas aeruginosa Isolates at a Tertiary Hospital in Istanbul, Turkey
    (Mary Ann Liebert, Inc, 2017) Malkocoglu, Guelsah; Aktas, Elif; Bayraktar, Banu; Otlu, Baris; Bulut, Mehmet Emin
    Worldwide increase in carbapenem resistance and transferable carbapenemases are significant challenges in treatment of Pseudomonas aeruginosa infections. In this study, investigation of carbapenemase production in carbapenem-resistant P. aeruginosa isolates recovered from clinical specimens in a tertiary hospital was aimed. A total of 84 carbapenem-resistant P. aeruginosa isolates were examined. Carbapenem inactivation method (CIM) was used for phenotypic detection of carbapenemase production. The existence of bla(KPC), bla(NDM), bla(IMP), bla(VIM), bla(OXA-48), and bla(GES) genes was investigated by polymerase chain reaction (PCR). Subtypes of the detected genes were identified by sequence analysis. Arbitrarily primed PCR (AP-PCR) was performed to evaluate the clonal relationship among the isolates. The presence of high-risk clones in carbapenemase producers was investigated by Matrix-assisted laser desorption/ionizationtime of flight mass spectrometry (MALDI-TOF MS). Three isolates (3.5%) were identified as carbapenemase producers by CIM tests, while PCR tests demonstrated three isolates carrying carbapenemase genes as well. bla(VIM) gene was found in two isolates and bla(GES) gene was found in one isolate. Sequence analysis demonstrated that the carbapenemases were VIM-1, VIM-2, and GES-5. AP-PCR yielded high clonal diversity among the isolates. According to MALDI-TOF MS analysis, none of the carbapenemase-producing strains belonged to the high-risk clones. In conclusion, the presence of VIM-1, VIM-2, and GES-5 type carbapenemases in P. aeruginosa isolates was demonstrated for the first time in our hospital, GES-5 being reported for the second time in Turkey. Our results will lead strategies for controlling the spread of carbapenemases and contribute to epidemiological data from Turkey.
  • Küçük Resim Yok
    Öğe
    VIM-1, VIM-2, and GES-5 Carbapenemases Among Pseudomonas aeruginosa Isolates at a Tertiary Hospital in Istanbul, Turkey.
    (Microbial Drug Resistance, 2017) Malkoçoğlu, Gülşah; Aktaş, Elif; Bayraktar, Banu; Otlu, Barış; Bulut, Mehmet Emin
    Worldwide increase in carbapenem resistance and transferable carbapenemases are significant challenges in treatment of Pseudomonas aeruginosa infections. In this study, investigation of carbapenemase production in carbapenem-resistant P. aeruginosa isolates recovered from clinical specimens in a tertiary hospital was aimed. A total of 84 carbapenem-resistant P. aeruginosa isolates were examined. "Carbapenem inactivation method" (CIM) was used for phenotypic detection of carbapenemase production. The existence of blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48, and blaGES genes was investigated by polymerase chain reaction (PCR). Subtypes of the detected genes were identified by sequence analysis. Arbitrarily primed PCR (AP-PCR) was performed to evaluate the clonal relationship among the isolates. The presence of high-risk clones in carbapenemase producers was investigated by Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Three isolates (3.5%) were identified as carbapenemase producers by CIM tests, while PCR tests demonstrated three isolates carrying carbapenemase genes as well. blaVIM gene was found in two isolates and blaGES gene was found in one isolate. Sequence analysis demonstrated that the carbapenemases were VIM-1, VIM-2, and GES-5. AP-PCR yielded high clonal diversity among the isolates. According to MALDI-TOF MS analysis, none of the carbapenemase-producing strains belonged to the high-risk clones. In conclusion, the presence of VIM-1, VIM-2, and GES-5 type carbapenemases in P. aeruginosa isolates was demonstrated for the first time in our hospital, GES-5 being reported for the second time in Turkey. Our results will lead strategies for controlling the spread of carbapenemases and contribute to epidemiological data from Turkey.