Use of the GenoType？ MTBDRplus assay to assess drug resistance of Mycobacterium tuberculosis isolates from patients in rural Uganda

We enrolled, consecutively, all newly diagnosed and previously treated smear-positive TB patients aged ≥ 18 years. Isolates were tested for drug resistance against rifampicin (RIF) and isoniazid (INH) using the Genotype？ MDRTBplus assay and results were compared with those obtained by the indirect proportion method on Lowenstein-Jensen media. HIV testing was performed using two rapid HIV tests.A total of 125 isolates from 167 TB suspects with a mean age 33.7 years and HIV prevalence of 67.9% (55/81) were analysed. A majority (92.8%) of the participants were newly presenting while only 7.2% were retreatment cases. Resistance mutations to either RIF or INH were detected in 6.4% of the total isolates. Multidrug resistance, INH and RIF resistance was 1.6%, 3.2% and 4.8%, respectively. The rpoβ gene mutations seen in the sample were D516V, S531L, H526Y H526 D and D516V, while one strain had a Δ1 mutation in the wild type probes. There were three strains with katG (codon 315) gene mutations while only one strain showed the inhA promoter region gene mutation.The TB resistance rate in Mbarara is relatively low. The GenoType？ MTBDRplus assay can be used for rapid screening of MDR-TB in this setting.Despite the availability of drugs to treat tuberculosis (TB), it remains the world's leading cause of death from a single infectious disease. The World Health Organization (WHO) estimates current rates of multidrug resistant TB (resistance to at least isoniazid and rifampicin) in new and previously treated cases globally at 2.9% and 15.3% respectively, with 57% of multidrug resistant tuberculosis (MDR-TB) cases coming from three high burden countries (China, India, and the Russian Federation) [1].Uganda is currently ranked 16th among the highest TB burdened countries in the world [2]. The prevalence of MDR-TB in new cases in this setting has previously been reported to be low at less than 2% [3]. However, there are recent reports that 12.7% of re-treatment cases attending the Nati