Molecular Detection of Drug-Resistant Mycobacterium tuberculosis in Sputum Specimens from the New and Previously Treated Tuberculosis Cases at the National Reference Chest Diseases Laboratory in Lusaka, Zambia

Background: Drug-Resistant Tuberculosis (DR-TB) is one of the major public health issues globally. Zambia highly burdened by TB and multi-drug resistant TB. In this study, sputum samples obtained from new previously treated cases were examined for drug-resistant Mycobacterium tuberculosis (MTB). Methods: Sputum specimens processed using N-acetyl-L-cysteine-sodium hydroxide method, stained fluorescent technique microscopy respectively. Mycobacterial DNA was extracted Genolyse kit, then subjected to multiplex polymerase chain reaction amplification reverse hybridization. Drug-resistance mutations in MTB genes detected Genotype MTBDRplus VER 2.0 MTBDRsl assays. Results: A total 329 MTB-positive specimens, 102 227 cases, analysed drug-resistance. Among 3.9% had Rifampicin (RIF) mono-resistance, 12.8% Isoniazid (INH) 17.7% Multi-Drug Resistance (MDR). For 10.1% RIF 6.6% INH 33.0% MDR, 1.8% poly-drug resistance, 0.8% pre-Extensively Drug-Resistance (pre-XDR). Mutations identified rpoB (Ser531Leu, His526Asp, Asp516Val, His526Tyr, Glu510His), katG (Ser315Thr 1 Ser315Thr 2), InhA (Cys15Thr), gyrA (Ala90Val Asp94Gly), eis (Cys14Thr), each with a varying frequency. Conclusion: DR-TB prevalent, especially MDR-TB, which currently most worrisome form an emerging threat hampering efforts control Zambia. The early detection effective treatment are key DR-TB.