Microscopic-Observation Drug-Susceptibility Asay Detecting Rapidly Drug Resistant and Multidrug Resistant Mycobacterium Tuberculosis

Abstract

Backround: Tuberculosis remains a major cause of morbidity and mortality in many countries and a significant public health problem worldwide. If TB is detected early and properly treated, the patients quickly become non-infectious and are eventually cured. Objective: Using MODS assay for detecting rapidly drug resistant and multidrug resistant M. tuberculosis. Methods: The MODS assay for the detection of tuberculosis and drug-resistant tuberculosis, directly from 252 sputum samples from suspected tuberculosis patients or untreated or ≤ 2 weeks treated tuberculosis patients. Culturing and doing susceptibility test by MODS assay (Issoniazid: 0.1 µg/ml; rifampicin: 1 µg/ml, Streptomycin: 2 µg/ml và Ethambutol: 2.5 µg/ml). Realtime PCR 16S was performed for the MODS culture-positive samples before 7 days and the samples with MODS culture-negative but AFB-positive. Results: M.tuberculosis was detected in 153 samples (60.7%) and 46 (30.1%) were antibiotic resistant. One drug resistance was present in 30 strains (19.6%): 18 for RIF, 6 for INH and 3 for STR and EBM. Multidrug resistant M.tuberculosis as defined by WHO (resistant to RIF and INH) was observed in 13 strains. There were additional 14 strains showing resistance to two or more drugs. Conclusion: The MODS assay is a rapid, direct method for simultaneous culture detection and drug susceptibility of M. tuberculosis, can be used as a routine procedure.