Performance of GenoType® MTBDRplus assay in the diagnosis of drug-resistant tuberculosis in Tangier, Morocco.

Abstract Objectives In Morocco, tuberculosis (TB) is a major public health problem with high morbidity and mortality. The main problem faced by the National TB program is the high rate of drug resistant (DR), particularly multi-drug resistant (MDR) strains. Diagnosis of DR-TB is mainly performed by conventional techniques which are time consuming with limited efficacy. In 2014, GenoType ® MTBDR plus assay was introduced in Morocco for drug resistance testing. In this regard, the present study was planned to assess the diagnostic accuracy of GenoType ® MTBDR plus assay. Methods A total of 70 samples, from suspected cases in Tangier − Morocco, were analyzed by conventional drug susceptibility testing and GenoType ® MTBDR plus assay. Results Among them, 37.14% were MDR, whereas mono-resistance to isoniazid (INH) and rifampin (RIF) was detected in 18.57% and 17.14% strains respectively. Using GenoType ® MTBDR plus approach, 12 isolates were identified as INH mono-resistant (17.14%), 9 as RIF mono-resistant (12.86%) and 26 as MDR (37.14%). rpoB531 and katG315 mutations were the most common ones found to be associated with resistance to RIF and INH, respectively. Significantly, all phenotypic MDR strains were also MDR by GenoType ® MTBDR plus assay. The sensitivity of genotype ® MTBDR plus was 92.1% and 97.4% for RIF and INH resistance respectively; whereas the specificity was 100% for the two tested drugs. Conclusion GenoType ® MTBDR plus assay is a rapid, reliable and accurate tool for the detection of DR-TB in clinical specimens. Its routine use will be of a great interest to prevent the dissemination of resistant TB forms in the community.