Drug susceptibility testing and line probe assay of first-line anti-tuberculosis drugs among presumptive tuberculosis patients attending a secondary care hospital in Bhubaneswar

Background:Pyrazinamide (PZA) is important for identification in multi-drug-resistant tuberculosis patients before starting therapy. PZA drug susceptibility testing (DST) is essential for the management of drug-resistant and susceptible TB patients.Aims:The degree of drug resistance among TB patients and discrepancy between DST results of the phenotype and genotype were assessed.Materials and Methods:Socio-demographic and clinical profiles of TB patients recruited in the study were documented. Sputum samples were processed for diagnosis using TrueNat Xpert MTB, TrueNat Xpert MTB Plus, and MGIT culture.Results:Rifampicin (RIF) line probe assay (LPA) showed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100%, whereas isoniazid (INH) LPA testing showed a sensitivity of 85.7%, a specificity and PPV of 100%, and NPV of 94.8%. The gene mutation for RIF resistance was between the codon, 530-533 of rpoB gene, and that for INH resistance was at the codon, 315 of katG gene.Conclusion:Our findings demonstrated high prevalence of mono- and poly-drug resistance as well as pyrazinamide resistance.