Performance of the MTBDRsl assay in Georgia

Abstract

Setting The country of Georgia has a high burden of multidrug and extensively drug-resistant tuberculosis (M/XDR-TB). Objective To assess the performance of the Genotype MTBDRsl assay in the detection of resistance to Kanamycin (KAN), Capreomycin (CAP), Ofloxacin (OFX), and XDR. Design Consecutive AFB smear positive sputum specimens identified as MDR by MTBDRplus testing were evaluated with the MTBDRsl assay and conventional second-line drug susceptibility testing (DST). Results Among 159 specimens, amplification was adequate in 154 (97%), including 9 of 9 culture negative and 2 of 3 contaminated specimens. Second-line DST revealed 17 (12%) M. tuberculosis isolates were XDR. Compared to DST, the MTBDRsl had 41% sensitivity and 98% specificity in detecting XDR and an 81% sensitivity and 99% specificity in detecting OFX resistance. Sensitivity was low in detecting resistance to KAN (29%) and CAP (57%) while specificity was 99% and 94%, respectively. Median times from sputum collection to second-line DST and MTBDRsl results were 70–104 versus 10 days. Conclusion The MTBDRsl assay had a rapid turn around time; however detection of second-line drug-resistance was poor compared to DST. Further genetic mutations associated with resistance to second-line drugs should be included in the assay to improve test performance and clinical utility.

Evaluation of the BACTEC MGIT 960 SL DST Kit and the GenoType MTBDRsl Test for Detecting Extensively Drugresistant Tuberculosis Cases

“…However, the sensitivity rate for OFL in our study was higher than those reported by Tukvadze et al [17] and Jin et al [18]. Our results were consistent with those of the meta-analysis study of Theron et al [19] in which performance of the GenoType MTBDRsl method was evaluated by analyzing 21 studies.…”

Predicting Extensively Drug-Resistant Mycobacterium tuberculosis Phenotypes with Genetic Mutations

“…However, they should still have a sensitivity of ϳ90% for KAN r in countries, such as India and South Africa, where we observed KAN r being associated mostly with rrs mutations. The lack of eis probes in these LPAs likely contributed to the poor sensitivity (ϳ50%) recently reported for the MTBDRsl assay for the detection of aminoglycoside-resistant isolates from the country of Georgia (42). Adding eis promoter SNPs (Ϫ10G¡A, Ϫ12C¡T, and Ϫ14C¡T) to existing second-line LPAs and future molecular diagnostics would increase their utility globally and provide added confidence for the detection of KAN r in regions where rrs/eis frequencies are not yet known.…”

High-dose vitamin D3 in adults with pulmonary tuberculosis: a double-blind randomized controlled trial

“…All sputum samples had AFB cultures performed with the use of Löwenstein-Jensen solid media and standard methodologies as previously reported (24,25). Positive cultures were confirmed to be Mtb complex with the use of phenotypic tests and the Genotype MTBDRplus assay (Hain Lifescience; www.hain-lifescience.de) (24,25).…”

“…A smear microscopy was performed at the NCTLD by the National Tuberculosis Reference Laboratory with the use of Ziehl-Neelsen staining as previously described (24,25). All sputum samples had AFB cultures performed with the use of Löwenstein-Jensen solid media and standard methodologies as previously reported (24,25). Positive cultures were confirmed to be Mtb complex with the use of phenotypic tests and the Genotype MTBDRplus assay (Hain Lifescience; www.hain-lifescience.de) (24,25).…”

“…A smear microscopy was performed at the NCTLD by the National Tuberculosis Reference Laboratory with the use of Ziehl-Neelsen staining as previously described (24,25). All sputum samples had AFB cultures performed with the use of Löwenstein-Jensen solid media and standard methodologies as previously reported (24,25).…”