Mycobacterium Tuberculosis Genetic Diversity and Drug Resistance Conferring Mutations in the Democratic Republic of the Congo

Background: The Democratic Republic of the Congo (DRC) belongs to the 22 tuberculosis (TB) high-burden countries and to the 27 high-burden multidrug-resistant (MDR)-TB countries. To date, there are no data on the genetic diversity of Mycobacterium tuberculosis in the DRC. Objective: To describe the genetic diversity and the distribution of drug resistance conferring mutations of clinical M. tuberculosis isolates from the DRC. Design: We analysed consecutive M. tuberculosis single patient isolates cultured in 2010 at the laboratory of the National TB Control Programme in Kinshasa. Setting: National TB Control Programme in Kinshasa, DRC. Results: Isolates from 50 patients with pulmonary TB were analysed, including 45 patients (90%) who failed treatment. All isolates belonged to the Euro-American lineage (main phylogenetic Lineage 4). Six different spoligotype families were observed within this lineage, including LAM (20 patients, 40%), T (15 patients; 30%), U (4 patients; 8%), S (3 patients; 6%), Haarlem (2 patients; 4%), and X (1 patient; 2%). No M. africanum strains were observed. The most frequently detected drug  resistance-conferring mutations were rpoB S531L and katG S315T1. Various other mutations, including previously unreported mutations, were detected. Conclusions: The Euro-American lineage dominates in the DRC, with substantial variation in spoligotype families. This study fills an important gap on the molecular map of M. tuberculosis in sub-Saharan Africa.