title: Comparative evaluation of the microplate nitrate reductase assay and the rezasurin microtitre assay for the rapid detection of multidrug resistant Mycobacterium tuberculosis clinical isolates.
abstract: The microplate nitrate reductase assay (MNRA) and the rezasurin microtitre assay (REMA) were used for the susceptibility testing of 73 clinical isolates and the results were compared with those that were obtained using the Bactec 460 TB and Bactec MGIT 960 systems. The REMA and the MNRA were performed in 96-well plates. For the REMA, the concentrations of isoniazid (INH) and rifampicin (RIF) ranged from 1.0-0.01 µg/mL and 2.0-0.03 µg/mL, respectively. For the MNRA, the INH concentration was between 1.0-0.03 µg/mL and the RIF concentration was between 2.0-0.06 µg/mL. For the MNRA, the sensitivity, specificity, positive predictive value, negative predictive value and INH/RIF agreement were 100/95.6, 97.6/100, 96.8/100, 100/98 and 98.6/98.6, respectively, and for the REMA, they were 100/91.3, 90.4/100, 88.5/100, 100/96.1 and 94.5/97.2, respectively. Our data suggest that these two rapid, low-cost methods may be inexpensive, alternative assays for the rapid detection of multidrug resistant tuberculosis in low-income countries.
authors.affiliation: Department of Medical Microbiology, Medical School, Ondokuz Mayis University, Samsun, Turkey. cobanay2003@gmail.com
authors.forename: Ahmet Yilmaz
authors.initials: AY
authors.lastname: Coban
authors.forename: Meltem
authors.initials: M
authors.lastname: Uzun
authors.forename: Alper
authors.initials: A
authors.lastname: Akgunes
authors.forename: Belma
authors.initials: B
authors.lastname: Durupinar
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D050901:Nitrate Reductase / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012293:Rifampin / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology; D014966:Xanthenes / Q000378:metabolism
chemical_list: D000995:Antitubercular Agents; D010078:Oxazines; D011933:Reagent Kits, Diagnostic; D014966:Xanthenes; C005843:resazurin; D050901:Nitrate Reductase; D007538:Isoniazid; D012293:Rifampin