Usefulness of Genotype MTBDRplus assay in acid-fast bacilli positive smear specimens in Almeria, Spain

Abstract

Introduction: The urgent need for operational research evaluating test performance in a real-world setting has been highlighted. The purpose of this study was therefore to evaluate the performance of MTBDRplus assay.

Materials: According to the reference method, of the 155 clinical specimens with valid results, 147 were susceptible to rifampicin (RIF) and isoniazid (INH), with 4 being multi-drug resistant (MDR) and 4 with isolated resistance to isoniazid (INH).

Results: The results of the MTBDRplus assay were 100% concordant for the MDR and mono-resistant to INH specimens. However, the MTBDRplus assay showed a resistance pattern to RIF in one specimen which was classified as susceptible by the reference method. The majority of the specimens (118/75.6%) were also tested using the MTBDRplus method after culture on Lowenstein-Jensen media, showing 100% agreement with the results of the test directly from the specimens. An MTBDRplus test result was available within an average of 8 days.

Conclusions: Overall, MTBDR results showed excellent results when compared with the reference method and achieved a significant time-reduction.

Keywords: Comparación; Comparison; Genotype MTBDRplus; Molecular susceptibility; Reducción tiempo de respuesta; Susceptibilidad molecular; Time reduction.