Resazurin tube method: Rapid, simple, and inexpensive method for detection of drug resistance in the clinical isolates of Mycobacterium Tuberculosis

Abstract

Background:Tuberculosis (TB) remains a serious public health problem worldwide. The emergence of drug resistance and multidrug resistance (MDR) has become the main threat to TB treatment and control programs. Rapid detection is critical for the effective treatment of patients. In recent times, a new method using the colorimetric indicator resazurin has been proposed for drug susceptibility of Mycobacterium tuberculosis.Materials and Methods:In this study, the resazurin reduction assay was adapted to screw cap tubes. Using the Resazurin Tube Method (RTM), a total of 100 clinical isolates were tested against Rifampicin (RIF) and Isoniazide (INH). By visual reading, the minimum inhibitory concentrations (MICs) were obtained after eight days. The results obtained were compared with the gold standard proportion method.Results:Excellent results were obtained for RTM with a sensitivity of 100% for both RIF and INH, with a specificity of 98.7 and 95.3%, respectively. Kappa is the measure of agreement between the RTM and proportion method (PM) for RIF and INH, which was found to be 0.972 and 0.935 for RIF and INH, respectively.Conclusion:The RTM appears to be a reliable method for the rapid and simultaneous detection of MDR-TB and drug susceptibility testing (DST) of M. tuberculosis. It is simple, inexpensive, and with no biohazard risk involved.

Insights into the in-vitro Susceptibility and Drug–Drug Interaction Profiles Against Drug-Resistant and Susceptible Mycobacterium tuberculosis Clinical Isolates in Amhara, Ethiopia

“…At the time of the experiment, a working solution for each drug concentration was prepared by diluting stock solutions in M7H9 broth that was supplemented with OADC (BD Difco BBL, NJ, USA) 15 at four times (4x) the final highest concentration (4µg/mL for INH, 8µg/mL for RIF, and 32 µg/mL for LEV, and 64µg/mL for EMB). The final drug concentrations tested were 1µg/mL for INH, 2µg/mL for RIF, 27 , 28 8 µg/mL for LEV and 16µg/mL for EMB in 96-well plates. 29 , 30 LEV was found to be more efficacious than other ofloxacin (OFX) when incorporated into multidrug regimens for treatment of MDR-TB.…”

Latent TB Detection and Isolation of MDR TB Bacteria in, MP, India

“…The patients were needed to be under strict medical completely to hold the establishment of bacteria to dormant latent infectious disease establishment to eliminate tuberculosis completely the tuberculosis of latent infection should be encouraged, apart from encouraging patient if infected by resistant strain to complete regimen. Resazurin Tube Method: rapid, simple, and inexpensive method for detection of drug resistance in the clinical isolates of Mycobacterium tuberculosis [34], evidence based management of drug resistant tuberculosis was put forwarded [35] and intensive therapy for treatment of latent TB was suggested [36] which intrigued us to study the existence IGRA in clinical suspects in population of Indore and the region around presented in this publication.…”

Osmium–arene complexes with high potency towards Mycobacterium tuberculosis

“…The MIC of all compounds was determined using the resazurin microtitre assay, as described previously. 40 Compounds were dissolved in dimethylsulfoxide (DMSO) and then diluted so that the final concentration in the media did not exceed 2% v/v. Mtb H37Rv was grown to mid-log phase [optical density at 600 nm (OD 600 ) of 0.6] and the inoculum was standardized to 1 × 10 6 colony-forming units (CFUs)/mL before addition to a prepared 96-well flat bottom microtitre plate with 2-fold serial dilutions of each compound in media.…”