title: Molecular approaches for detection of the multi-drug resistant tuberculosis (MDR-TB) in Bangladesh.
abstract: The principal obstacles in the treatment of tuberculosis (TB) are delayed and inaccurate diagnosis which often leads to the onset of the drug resistant TB cases. To avail the appropriate treatment of the patients and to hinder the transmission of drug-resistant TB, accurate and rapid detection of resistant isolates is critical. Present study was designed to demonstrate the efficacy of molecular techniques inclusive of line probe assay (LPA) and GeneXpert MTB/RIF methods for the detection of multi-drug resistant (MDR) TB. Sputum samples from 300 different categories of treated and new TB cases were tested for the detection of possible mutation in the resistance specific genes (rpoB, inhA and katG) through Genotype MTBDRplus assay or LPA and GeneXpert MTB/RIF tests. Culture based conventional drug susceptibility test (DST) was also carried out to measure the efficacy of the molecular methods employed. Among 300 samples, 191 (63.7%) and 193 (64.3%) cases were found to be resistant against rifampicin in LPA and GeneXpert methods, respectively; while 189 (63%) cases of rifampicin resistance were detected by conventional DST methods. On the other hand, 196 (65.3%) and 191 (63.7%) isolates showed isoniazid resistance as detected by LPA and conventional drug susceptibility test (DST), respectively. Among the drug resistant isolates (collectively 198 in LPA and 193 in conventional DST), 189 (95.6%) and 187 (96.9%) were considered to be MDR as examined by LPA and conventional DST, respectively. Category-II and -IV patients encountered higher frequency of drug resistance compared to those from category-I and new cases. Considering the higher sensitivity, specificity and accuracy along with the required time to results significantly shorter, our study supports the adoption of LPA and GeneXpert assay as efficient tools in detecting drug resistant TB in Bangladesh.
authors.affiliation: Department of Microbiology, Stamford University Bangladesh, Dhaka, Bangladesh.
authors.forename: Tafsina Haque
authors.initials: TH
authors.lastname: Aurin
authors.affiliation: Department of Microbiology, Stamford University Bangladesh, Dhaka, Bangladesh.
authors.forename: Saurab Kishore
authors.initials: SK
authors.lastname: Munshi
authors.affiliation: National Tuberculosis Reference Laboratory (NTRL), NIDCH, Mohakhali, Dhaka, Bangladesh.
authors.forename: S M Mostofa
authors.initials: SM
authors.lastname: Kamal
authors.affiliation: University Research Co., LLC (URC), Banani, Dhaka, Bangladesh.
authors.forename: Md Mostafizur
authors.initials: MM
authors.lastname: Rahman
authors.affiliation: National Tuberculosis Reference Laboratory (NTRL), NIDCH, Mohakhali, Dhaka, Bangladesh.
authors.forename: Md Shamim
authors.initials: MS
authors.lastname: Hossain
authors.affiliation: National Tuberculosis Reference Laboratory (NTRL), NIDCH, Mohakhali, Dhaka, Bangladesh.
authors.forename: Thaythayhla
authors.initials: T
authors.lastname: Marma
authors.affiliation: Department of Microbiology, Stamford University Bangladesh, Dhaka, Bangladesh.
authors.forename: Farjana
authors.initials: F
authors.lastname: Rahman
authors.affiliation: Department of Microbiology, Stamford University Bangladesh, Dhaka, Bangladesh.
authors.forename: Rashed
authors.initials: R
authors.lastname: Noor
mesh_terms: D001459:Bangladesh; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012293:Rifampin / Q000494:pharmacology / Q000627:therapeutic use; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology
chemical_list: D012293:Rifampin