Browsing by Author "Sürücüoğlu S."

Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    Evaluation of the performance of maldi-tof ms and dna sequence analysis in the identification of mycobacteria species
    (Turkiye Klinikleri Journal of Medical Sciences, 2018) Akyar I.; Çavuşoğlu C.; Ayaş M.; Sürücüoğlu S.; İlki A.; Kaya D.E.; Beşli Y.
    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. © TÜBİTAK.
  • No Thumbnail Available
    Item
    The reliability of tuberculin skin test in the diagnosis of latent tuberculosis infection in psoriasis patients: A case-control study
    (Blackwell Publishing Inc., 2020) Sürücüoğlu S.; Türel Ermertcan A.; Çetinarslan T.; Özkütük N.
    Tuberculin skin test (TST), which is used in the diagnosis of latent tuberculosis infection, may cause Koebner's phenomenon and false-positive results in psoriasis patients. The purpose of this study is to compare TST with QuantiFERON-TB Gold Plus (QFT-plus) test in psoriasis patients and to determine the effects of psoriasis on TST results. Ninety-two psoriasis patients and 30 control subjects were included in the study. QFT-plus test, TST, and prick test to distinguish the increase of induration because of the skin trauma were performed on both groups. The demographics, risk factors for latent tuberculosis infection, BCG vaccination history, Koebner's history, psoriasis severity, and treatment history of the patients were recorded. The effects of these variables on test results were investigated by comparing those with control group. The criteria of National Tuberculosis Diagnosis and Treatment Guidelines were used in the evaluation of test results, and threshold value of positivity for TST was taken as 10 mm in BCG-vaccinated patients who are planned to start biological treatment. Prick test results were negative in the control group. There was no significant relation between the results of prick test and TST induration diameters in the patient group. Although TST positivity was significantly higher in patients (62%) compared with control group (33%), QFT-plus test results were not statistically different between two groups. Agreement between two tests was determined to be low in patient group with 48% (K = 0.1), and it was determined to be moderate with 77% in control group (K = 0.4). QFT-plus test was found to be negative in 46 of 57 TST-positive patients (80.7%) in patient group. It was determined in both groups that vaccination did not have any effect on test results. When threshold value was lowered to 5 mm in patient group without considering BCG reaction, the number of TST-positive patients increased from 57 to 65. Mean TST induration diameter was 10 mm and 14 mm in cases with mild and moderate to severe clinical manifestation, respectively (P =.04). However, no effect of disease period and treatment was determined on both test results. TST positivity was higher in psoriasis patients compared with control group. It was considered due to the increased reaction of the skin to mycobacterial antigens rather than the Koebner's response. Although TST results were not affected by BCG, it was concluded that a 10-mm threshold value of positivity was a suitable approach in order to reduce the number of patients receiving unnecessary preventive treatment in patients who are considered to initiate biologic agents. Furthermore, it was also concluded that QFT-plus test may be preferred in psoriasis patients since it is applied in vitro and its specificity is higher and not affected by disease severity. © 2020 Wiley Periodicals LLC.
  • No Thumbnail Available
    Item
    Evaluation of the performance of LED fluorescent microscopy in diagnosis of tuberculosis; [Tüberküloz tanısında LED floresan mikroskopi performansının değerlendirilmesi]
    (Refik Saydam National Public Health Agency (RSNPHA), 2022) Erdal G.; Sürücüoğlu S.; Özkütük N.
    Objective: The aim of the study is to compare of the results of LED fluorescent microscopy (LED FM) and Ehrlich Ziehl Neelsen (EZN) staining in the examination of the respiratory specimens and to evaluate the performance of LED fluorescent microscopy with culture. Methods: In the study, the respiratory specimens obtained from patients prediagnosed with pulmonary tuberculosis were examined in the Tuberculosis Laboratory of Manisa Celal Bayar University Hafsa Sultan Hospital between February 2018 and November 2019. Two smears from each specimen processed with NALC-NaOH method were prepared and they were evaluated both EZN and LED FM by blind readers. The results of culture were used as reference for determination of the performance of LED FM. Results: In the study 1499 respiratory specimens were evaluated with LED FM. Mycobacteria were grown in the culture of 134 specimens (8.9%). The sensitivity, specificity, positive predictive value, and negative predictive value of LED FM were found as 64.2% (95% GI, 61.8%-64.4%), 96% (95%GI, 95.7%-96.3%), 61.4% and 96.5%, respectively. The sensitivity, specificity, positive and negative predictive values of EZN were also found as 51.5% (95% GI, 49%-54%), 99.9% (95% GI, 99.7%-99.9%), 97.2% and 95.4%, respectively. However, smear scarce-culture negative results (54/1365) with LED FM were obtained significantly higher than the results with EZN (0/1365, p=0.000). The reason of this was thought to be due to the lack of the experience of the readers. The reading time of LED FM was 69% time saving. The consistency between the readers was found to be good (Kappa value=0.71) and it was determined that LED FM could be preferred in routine examination as a result of the survey conducted to the readers. Conclusion: The sensitivity of LED FM was found 12.7% higher than the sensitivity of EZN. However, because of the high rate of false positive results, the introduction of LED-FM should be accompanied by appropriate training of the readers. It is also thought that the use of LED FM will be cost-effective in large-scale laboratories in our country. © 2022,Turk Hijyen ve Deneysel Biyoloji Dergisi,All rights reserved
  • No Thumbnail Available
    Item
    In vitro Activity of Rifabutin and Clofazimine to Macrolide-Resistant Mycobacterium abscessus Complex Clinical Isolates; [Rifabutin ve Klofaziminin Makrolidlere Dirençli Mycobacterium abscessus Kompleks Klinik İzolatlarına In vitro Etkinliği]
    (Ankara Microbiology Society, 2023) Sürücüoğlu S.; Özkütük N.; Gazi H.; Çavuşoğlu C.
    Mycobacterium abscessus complex (MABSC) is one of the most resistant bacteria against antimicrobial agents. The number of agents that can be used by oral route, such as macrolides, is limited in antimicrobial therapy. In recent years, rifabutin and clofazimine have gained importance as they can be administered by oral route and have shown synergistic effects with macrolides and aminoglycosides. The aim of this study was to determine the in vitro activity of rifabutin and clofazimine against clinical isolates of MABSC resistant to macrolides. A total of 48 MABSC isolates obtained from respiratory tract and other clinical samples in the Tuberculosis Laboratories of the Faculty of Medicine of Manisa Celal Bayar and Ege Universities were included in the study. Subspecies differentiation and aminoglycoside and macrolide resistance of the isolates were determined by GenoType NTM-DR test. Rifabutin and clofazimine susceptibilities were determined by standard broth microdilution method. Of the MABSC isolates 42 were identified as M.abscessus subsp. abscessus, three as M.abscessus subsp. bolletii and three as M.abscessus subsp. massiliense. None of the isolates exhibited rrs and rrl mutations indicating acquired macrolide resistance and aminoglycoside resistance. However, the erm(41) T28 genotype which is associated with inducible macrolide resistance was detected in 41 (85%) of the strains. All M.abscessus subsp. massiliense isolates were found to be genotypically susceptible to macrolides. The minimum inhibitory concentration (MIC) range values for rifabutin were 0.0625 to 32 µg/mL, while for clofazimine, the range was 0.0625 to 1 µg/mL. Rifabutin MIC values were significantly higher (mean 5.98 µg/mL vs 0.5 µg/mL, p= 0.026) in the isolates with macrolide resistance. There was no correlation between macrolide resistance and clofazimine MIC values (mean 0.25 µg/mL vs. 0.214 µg/mL, p= 0.758). The MIC50 and MIC90 values for rifabutin were 1 and 8 µg/mL, respectively, while for clofazimine they were 0.25 and 0.5 µg/mL. Macrolide resistance was found to be higher in isolates with rifabutin MIC values above the MIC50 value (p= 0.045). In conclusion, the determination of higher rifabutin MIC values in isolates resistant to macrolides suggested that susceptibility testing should be performed before adding rifabutin to the treatment regimen. The low MIC values of clofazimine in all strains indicated that it may be used as a first choice in the combination therapy. However, further studies using a larger number of clinical isolates and applying genotypic and phenotypic susceptibility tests are needed to determine threshold MIC values to assist clinicians in making treatment decisions. © 2023 Ankara Microbiology Society. All rights reserved.
  • No Thumbnail Available
    Item
    Antimicrobial Resistance Patterns of Mycobacterium abscessus Complex Clinical Isolates; [Mycobacterium abscessus Kompleks Klinik İzolatlarının Antimikrobiyal Direnç Özellikleri]
    (DOC Design and Informatics Co. Ltd., 2024) Sürücüoğlu S.; Özkütük N.; Gazi H.; Çavuşoğlu C.
    Objective: This study aimed to identify subspecies of Mycobacterium abscessus complex (MABC) isolates from clinical samples by a molecular technique and to determine mutations responsible for macrolide and aminoglycoside resistance. We also aimed to investigate the correlation of phenotypic and molecular test results by examining the resistance to antimicrobial agents according to CLSI standard using the liquid microdilution test. Methods: 27 MABC isolates from clinical samples were examined. Molecular subspecies identification and mutations responsible for aminoglycoside (rrs mutation) and macrolide resistance (rrl mutation) were determined using the GenoType NTM-DR test. The resistance phenotypes of the strains to various antimicrobial agents were investigated by the Sensititre™ RAPMYCOI AST microdilution test. Results: Of the 27 isolates tested, 21 were M. abscessus subsp. abscessus, three were M. abscessus subsp. bolletii, and three were M. abscessus subsp. massiliense; rrs and rrl mutations were not observed in any strains. Except for one isolate, all M. abscessus subsp. abscessus strains showed the erm(41) T28 genotype, which indicates inducible macrolide resistance. The correlation between the GenoType NTM-DR and phenotypic susceptibility test results was 81% (k=0.5, p=0.02) for inducible macrolide resistance and 89% for acquired macrolide resistance. The most effective antimicrobial agents were amikacin, cefoxitin, imipenem, linezolid, and tigecycline. Conclusion: Although the GenoType NTM-DR test is reliable in identifying and detecting molecular macrolide and aminoglycoside resistance, there were discrepancies in the results. We recommend confirming the results with the phenotypic susceptibility method after growth on culture. Although the M. abscessus complex is resistant to many antimicrobial agents, it has shown high sensitivity to amikacin, cefoxitin, imipenem, linezolid, and tigecycline. High levels of inducible macrolide resistance in isolates indicate the importance of subtyping and sensitivity testing of isolates in patients where culture conversion has not been achieved. © 2024, DOC Design and Informatics Co. Ltd. All rights reserved.