Molecular Characterization and RIF Resistance Mutation Pattern in Multi Drug Resistance Isolates Using Xpert MTB/RIF Assay in Clinical Isolates from Quetta, Pakistan

Multidrug-resistant tuberculosis (MDR-TB) is currently one of the seriousglobal challenges. With the advancement in the diagnostic facilities againsttuberculosis and the advent of Xpert assay, the diagnosis of MDR-TB hasbecome easier and more reliable. A total of 6353 specimens received at FatimaJinnah Chest Hospital, Quetta, were screened through fluorescent microscopyand GeneXpert assay from 2016 to 2018. The data collected were analyzedusing SPSS. Out of 6353 specimens, 1297 mycobacterium tuberculosis (MTB)positive cases were detected by Xpert assay, with 184 demonstrating rifresistance, mutations in the 81bp RRD region. The frequency of differentprobes was as follows: probe E 98/184 (53%), D 23/184 (12.5%), B 15/184(8.1%), C 5/184 (2.7%), A 3/184 (1.6%), double probe mutation 5/184 (2.7%),D&E 3/184 (1.6%), and C&D 2/184 (1%) and all 5-probe mutation 35/184(19%). A statistically significant association was found between probe typeand gender and treatment history, while no significant association was foundbetween probe type and age group of patients. MDR-TB prevalence was184/1297 (14.18%) with dominance of Probe E (53.26%) in the populationstudied. This study explores the increasing pattern of MDR-TB in the area.Effective measures should be adopted to curtail the disease in the area.