First Evaluation of GenoType MTBDRplus 2.0 Performed Directly on Respiratory Specimens in Central America

The turnaround times for conventional methods used to detect Mycobacterium tuberculosis in sputum samples and to obtain drug susceptibility information are long in many developing countries, including Panama, leading to delays in appropriate treatment initiation and continued transmission in the community. We evaluated the performance of a molecular line probe assay, the Genotype MTBDRplus version 2.0 assay, in detecting M. tuberculosis complex directly in respiratory specimens from smear-positive tuberculosis cases from four different regions in Panama, as well as the most frequent mutations in genes conferring resistance to isoniazid (katG and inhA) and rifampin (rpoB). Our results were confirmed with the nitrate reductase assay and genomic sequencing. M. tuberculosis complex was detected by the Genotype MTBDRplus 2.0 assay with 100% sensitivity and specificity. The sensitivity and specificity for rifampin resistance were 100% and 100%, respectively, and those for isoniazid resistance were 90.7% and 100%. Isoniazid monoresistance was detected in 5.2% of new cases. Genotype MTBDRplus 2.0 is highly accurate in detecting M. tuberculosis complex in respiratory specimens and is able to discriminate isoniazid-monoresistant cases from multidrug-resistant cases within 2 days.