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

Abstract

dThe 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 smearpositive 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.

Feasibility of Direct Sputum Molecular Testing for Drug Resistance as Part of Tuberculosis Clinical Trials Eligibility Screening

“…Diagnostic performance characteristics for LPA in our context were similar to those reported in nontrial settings on direct sputum, with a sensitivity of 88% and a specificity of 97% for the detection of INH resistance. Sensitivity for RIF resistance was 69%, lower than reported elsewhere [6,7], and might be due to the low prevalence of RIF resistance in our study (only 13 patients), the existence of alternative mutations conferring rifampicin resistance than identified by LPA testing, or possible coexisting drug-resistant and drug-susceptible strains or heteroresistance [12].…”

“…In Vietnam, sensitivity of 93.1% for rifampin (RIF) resistance, 92.6% for isoniazid (INH) resistance, and 88.9% for multidrug-resistant TB (MDR-TB) have been reported with 100% specificity [3]. Although less commonly used, MTBDR plus tested directly on sputum samples has demonstrated acceptable test performance characteristics compared to culture when used on smear-positive sputum samples in several settings [4,5,6,7]. Nevertheless, molecular testing on sputum is not routinely conducted.…”

CeRNA network identified hsa-miR-17-5p, hsa-miR-106a-5p and hsa-miR-2355-5p as potential diagnostic biomarkers for tuberculosis

“…[9] Xpert MTB/RIF assay is an emerging and available automatic molecular diagnosis method, while the high-cost restricts its widespread use. [10] Therefore, it is urgent to establish sensitive and efficient methods for the diagnosis of Mtb infection. Notably, relevant studies in non-coding RNAs have provided new avenues.…”