Browsing by Author "Akyuz, Sumeyye"

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Comparison of Carbapenem Resistance Detected by the Bd Phoenix Automated System in Enterobacteriaceae Isolates E-Test Method
(Modestum Ltd, 2022) Celik, Mehmet; Sunnetcioglu, Mahmut; Guducuoglu, Huseyin; Arslan, Yusuf; Akyuz, Sumeyye; Baran, Ali Irfan
Objective: Automatic identification and antimicrobial susceptibility systems are frequently used to identify clinical isolates in hospitalized patients, but mistakes in these systems can lead to potentially devastating treatment failures for patients. Therefore, the "Centers for Disease Control and Prevention (CDC)" recommends confirming all Carbapenem-resistant and low-susceptibility isolates with a different method. The aim of this study is to compare the Carbapenem susceptibility results of isolates reported as Carbapenem-resistant Enterobacteriaceae according to the BD Phoenix 100 automated system with the E-test method. Materials and Methods: The study included 70 strains of Carbapenem-resistant Enterobacteriaceae members which were isolated and grown from several types of clinical samples in the Medical Microbiology Laboratory. Conventional methods (Gram stain, negative oxidase test) and the BD Phoenix 100 automated system were used to identify the isolates. The susceptibility of all strains to imipenem, ertapenem and meropenem was investigated by E-test method. Automated system results and E-test results were compared. Results: The frequency distribution of all isolated bacterial strains comprised K. pneumoniae in 56 (80%) of the samples included in the study. The automated system test results were correlated with the results of the E-test at a rate of 96.1 % for the imipenem-resistant strains, 84.3% for the meropenem-resistant strains, 84.1% for the ertapenem-resistant strains Conclusions: Automated systems are frequently used in microbiology laboratories to identify isolates. However, automated systems can show a high error rate against some antimicrobials. For this reason, comparing the results of automated system test results with tests such as E-test is very important to prevent both treatment failures and inappropriate antibiotic use that may occur on a patient basis.
Delftia Acidovorans Pneumonia With Lung Cavities Formation
(Corporacion Editora Medica Valle, 2019) Yildiz, Hanifi; Sunnetcioglu, Aysel; Ekin, Selami; Baran, Irfan; Ozgokce, Mesut; Asker, Selvi; Akyuz, Sumeyye
Case Description: A 52-year-old female patient was admitted to our clinic with complaints of cough, sputum, fever and fatigue. The patient has been receiving immunosuppressive therapy for thrombocytopenic purpura for 5 years. Clinical Finding: Inspiratory crackles were heard on both hemithorax. Oxygen saturation measured with the pulse oximeter was 97%. Chest X-ray showed diffuse reticular opacities that were more prominent in the upper zones of both lungs. WBC counts were 17,600 mm(3) and Platelet counts were 29,000 mm3. Thorax CT showed that there were many thin-walled cavities and millimetric nodules accompanied by ground-glass infiltrates in the upper and middle lobes. Gram staining of bronchial fluid, taken by bronchoscopy, revealed Gram-negative bacilli and intense polymorphonuclear leukocytes. The bacteria were defined as Delftia acidovorans by BD Phoenix automated system. Treatment and outcomes: The patient was hospitalized with suspicion of opportunistic pulmonary infections and cavitary lung disease. After the empirical treatment of intravenous piperacillintazobactam and oral clarithromycin, her clinical and radiological findings significantly regressed, and she was discharged with outpatient follow-up. Clinical Relevance: This is the first example of cavitary pneumonia due to Delftia acidovorans in an immunocompromised patient. We would like to emphasize that Delftia pneumonia should be considered in the differential diagnosis of pulmonary cavitary involvement in such patients.
In-Vitro Activity of Ceftolozane-Tazobactam in Combination With Various Antibiotics Against Multidrug-Resistant Acinetobacter Baumannii Isolated From Intensive Care Patients
(Ankara Microbiology Soc, 2020) Akyuz, Sumeyye; Parlak, Mehmet; Guducuoglu, Huseyin
Acinetobacter species lead to nosocomial infections in immunocompromised patients hospitalized in intensive care units or services. Acinetobacter baumannii is a bacterium that is difficult to treat because it is intrinsically resistant to many antibiotics and can develop resistance afterwards. This situation limits the use of existing antibiotics and directs the clinician to new agents, different treatment options and the use of various antibiotic combinations. The aim of this study was to determine the sensitivities of doripenem (DOR), tigecycline (TGC), minocycline (MIN), amikacin (AK) and a newly developed agent ceftolozane-tazobactam (CT) in multidrug resistant A.baumannii strains which were isolated from inpatients in intensive care units and to investigate the in vitro interactions of CT/DOR, CT/TGC, CT/MIN and CT/AK combinations by using antibiotic gradient test method. Thirty-five A.baumannii strains isolated from various clinical specimens (blood, urine, sputum, tracheal aspirate, wound, abscess and catheter) between January 2017 and July 2017 were included in the study. Strains isolated from inpatients in intensive care units and resistant to at least three antibiotic classes were selected. The identification of A.baumannii isolates and the determination of routine antibiotic susceptibility profile were performed according to EUCAST 2017 criteria by the use of BD Phoenix 100 (Becton Dickinson, USA) automated system. Minimum inhibitor concentration values of CT, DOR, TGC, MIN, AK and combinations of CT with four other antibiotics (CT/DOR, CT/TGC, CT/MIN and CT/AK) were determined by antibiotic gradient test method. Fractional inhibitor concentration index (FICI) was used to determine the interactions of the combinations in vitro. According to the data obtained; the FICI was evaluated as synergy if FICI 5 0.5, additive if 0.5 > FICI <= 1, indifferent (unidentified interaction) if 1 < FICI < 2 and antagonist interaction if FICI >= 2. According to FICI results of the antibiotic combinations, the highest synergistic interaction was observed between CT/TGC as 11.4%. No synergistic interaction was observed between CT/DOR antibiotics. The highest additive interaction rates were between CT/AK (60%) and CT/MIN (45.7%), while no additive interaction between CT/DOR was observed. Antagonist interaction was observed in CT/DOR (71.4%) combination only. In conclusion, in our study it was observed that CT, a novel beta-lactam/ beta-lactamase inhibitor, did not sufficiently affect A.baumannii isolates, but was able to induce synergistic interaction in combination with TGC, AK and MIN. CT should be carefully monitored in clinical use because of the antagonist interaction detected with DOR.