Browsing by Author "Ceyhan I."

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    Multicentef evaluation of the indirect nitrate reductase assay for the rapid detection of multidrug-resistant tuberculosis; [Çok ilaca dirençli tüberkulozun hizli tespiti için dolayli nitrat redüktaz testinin çok merkezli deǧerlendirilmesi]
    (Ankara Microbiology Society, 2016) Çoban A.Y.; Taştekin B.; Uzun M.; Kalayci F.; Ceyhan I.; Biçmen C.; Albay A.; Siǧ A.K.; Özkütük N.; Sürücuoglü S.; Ozkütük A.; Esen N.; Albayrak N.; Aslanturk A.; Saribaş Z.; Alp A.
    Multidrug-resistant tuberculosis (MDR-TB) is defined as resistance to at least isoniazid (INH) and rifampicin (RIF), and it complicates the implementation of tuberculosis control programmes. The rapid detection of MDR-TB is crucial to reduce the transmission of disease. The nitrate reductase assay (NRA) is one of the colorimetric susceptibility test methods for rapid detection of MDR-TB and based on the ability of reduction of nitrate to nitrite by Mycobacterium tuberculosis. The aim of this study was to evaluate the performance of the NRA for the rapid detection of MDR-TB. A total of 237 M.tuberculosis complex (MTC) isolates that were identified by the same method (BD MGIT™ TBc Identification Test, USA) from nine different medical centers in Turkey were included in the study. The susceptibility results of the isolates against INH and RIF obtained by reference test (Bactec MGIT™ 960, BD, USA) were then compared with NRA. In order to ensure consistency between centers, Lowenstein-jensen (Lj) medium with antibiotics and without antibiotics (growth control) and Griess reagent solution were prepared in a single center (Ondokuz Mayis University School of Medicine, Medical Microbiology Department) and sent to all participant centers with the standardized test procedure. After the inoculation of bacteria into the test tubes, the tubes were incubated at 37°C, and after seven days of incubation, 500 pi Griess reagent was added to the L) medium without antibiotics. If a color change was observed, an equal volume of Griess reagent was added to test L) media with antibiotics. When a color change was observed in L) media with antibiotics, it was considered that the isolate was resistant to tested antibiotics. Among 237 MTC isolates, 16 were resistant only to INH and nine were resistant only to RIF; 93 isolates (39.2%) were resistant (MDR) and 119 isolates (50.2%) were susceptible to both of the drugs determined with the reference susceptibility test. In the study, five INH-resistant isolates determined with reference method were found susceptible with NRT and eight INH-susceptible isolates determined with reference method were found resistant with NRT. In contrast, one RIF-resistant isolate determined with reference method was found susceptible with NRT and three RIF-susceptible determined isolates were found resistant with NRT. Accordingly, the concordance rate between the reference method and NRA were estimated as 94.5% for INH and 98.3% for RIF. The sensitivity, specificity, positive and negative predictive values of NRA were detected as 95.4%, 93.7%, 92.8% and 96% for INH, and 99%, 97.8%, 97.1% and 99.2% for RIF, respectively. The results of the 111 isolates were obtained on the seventh day, while the rest of the results were obtained between 10-14 days. In conclusion, the data of this multicenter study showed that NRA is a reliable, relatively inexpensive and practical method to perform for the rapid detection of MDR-TB.
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    Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis
    (Nature Publishing Group, 2016) Coban A.Y.; Akbal A.U.; Bicmen C.; Albay A.; Sig A.K.; Uzun M.; Selale D.S.; Ozkutuk N.; Surucuoglu S.; Albayrak N.; Ucarman N.; Ozkutuk A.; Esen N.; Ceyhan I.; Ozyurt M.; Bektore B.; Aslan G.; Delialioğlu N.; Alp A.
    The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1–7. In the phase 2, 156 clinical isolates were tested in the center 1–6, center 8–11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2–96.8% for INH and 98.1–98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries. © 2016, The Author(s).
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    A new colorimetric method for rapid detection of ethambutol and streptomycin resistance in Mycobacterium tuberculosis: crystal violet decolorization assay (CVDA)
    (Springer Netherlands, 2019) Coban A.Y.; Akbal A.U.; Ceyhan I.; Uzun M.; Sertel Selale D.; Aslan G.; Delialioglu N.; Ozyurt M.; Bektore B.; Bicmen C.; Aslanturk A.; Ucarman N.; Albay A.; Sig A.K.; Ozkutuk N.; Surucuoglu S.
    Streptomycin (STR) and ethambutol (EMB) are important drugs used for the treatment of tuberculosis. There is a need for fast, reliable and inexpensive methods for detecting resistance to these drugs. The aim of this study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for the detection of STR and EMB resistance that is important drugs in tuberculosis treatment. In this study, drug susceptibility testing was performed on 140 Mycobacterium tuberculosis isolates provided from nine centers. Three tubes were used for each isolate. One of the tubes had a concentration of 2 mg/L STR and the other 5 mg/L EMB. The third was drug-free control tube. Sensitivity, specificity, positive predictive value (PPD), negative predictive value (NPD) and agreement for STR were found to be 81.8%, 94.6%, 87.8%, 91.5% and 90.57%, respectively. For EMB, sensitivity, specificity, PPD, NPD, and agreement were found to be 76%, 98.23%, 90.47%, 94.87% and 94.2%, respectively. The results were obtained in 11.3 ± 2.7 days (8–21 days). CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of STR and EMB resistance, and it could be adapted for drug susceptibility testing. © 2018, Springer Nature Switzerland AG.
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    Multicenter evaluation of AYC.2.2 agar for the isolation of mycobacteria from clinical samples
    (Indian Association of Medical Microbiologists, 2022) Coban A.Y.; Ceyhan I.; Uzun M.; Erkose Genc G.; Bicmen C.; Ozkutuk N.; Surucuoglu S.; Yanar O.; Aslan G.; Kurnaz N.; Tanriverdi Cayci Y.
    Purpose: The aim of this multicenter study is to evaluate AYC.2.2 agar for the isolation of mycobacteria from clinical samples. Methods: Totally 5559 media were tested in 7 centers. AYC.2.2 agar media for the study were prepared by C1 and sent to other centers under appropriate conditions. Other media except AYC.2.2 agar were purchased commercially. The media were subjected to routine laboratory operations in the center where they were sent. After the samples received for routine processing (in all centers, samples were processed with the same method (NALC-NaOH)), they were cultivated on routine media and AYC.2.2 agar afterward. Results: C1: Average growth time was determined as 12.74±3.74 days with MGIT 960 system; 24.42±4.75 days with LJ and 24.37±4.96 days with AYC.2.2 agar. C2: Average growth time was determined as 18.25±9.32 days with TK-Medium, 28.73±7.44 days with LJ, and 31.72±6.35 days with AYC.2.2 agar. C3: Average growth time was determined as 20.48±7.24 days with Ogawa medium, 20.74±7.12 days with LJ, and 20.26±7.43 days with AYC.2.2 agar. C4: Average growth time was determined as 15.27±6.37 days with MGIT 960 system, 22.14±9.1 days with LJ, and 22±8.45 days with AYC.2.2 agar. C5: Average growth time was determined as 13±4.24 days with MGIT 960 system, 32.16±6.23 days with LJ, and 33±5.73 days with AYC.2.2 agar. C6: Average growth time was determined as 9±3.11 days with MGIT 960 system, 18.68±5.32 days with LJ, and 18.34±4.63 days AYC.2.2 agar. C7: Average growth time was determined as 14.74±7.65 with MGIT 960 system, 26.01±8.21 days with LJ, and 26.24±7.88 days with AYC.2.2 agar. Conclusions: In conclusion, similar results were obtained with LJ and Ogawa media and AYC.2.2 agar. Furthermore, more studies should be conducted for isolation of M. tuberculosis and performing antibiotic susceptibility tests using AYC.2.2 agar before it can be used as a routine media in the laboratories. © 2022 Indian Association of Medical Microbiologists