Infection and Drug Resistance (Dec 2017)
Evaluation of a new automated Abbott RealTime MTB RIF/INH assay for qualitative detection of rifampicin/isoniazid resistance in pulmonary and extra-pulmonary clinical samples of Mycobacterium tuberculosis
Abstract
Pilar Ruiz,1 Manuel Causse,2 Manuel Vaquero,1 Juan Bautista Gutierrez,1,2 Manuel Casal1,2 1Mycobacteria Reference Center, Department of Microbiology, Faculty of Medicine and Nursing, University of Córdoba, Córdoba, Spain; 2Microbiology Laboratory, Reina Sofía University Hospital, Córdoba, Spain Abstract: A new automated real-time PCR assay for the detection of rifampicin (RIF) and isoniazid (INH) resistance in Mycobacterium tuberculosis (MTB) was evaluated. A total of 163 clinical samples (128 pulmonary and 35 extra-pulmonary) were processed using four PCR assay kits: Abbott RealTime MTB RIF/INH, Genotype MTBDRplus, Xpert/MTB RIF, and Anyplex MTB/MDR. The results of phenotypic drug-susceptibility testing using BACTECMGIT 960 were used as reference. The sensitivity and specificity of the new Abbott RealTime MTB RIF/INH assay in comparison with phenotypic testing was 96.3% (95%CI 87.32%–100%) for RIF and 100% (95%CI 99.3%–100%) for INH; the sensitivity was 78.8% (95%CI 66.8%–90.9%) and the specificity was 100% (95%CI 98.9%–100%). The Abbott RealTime MTB RIF/INH test could be a valid method for detecting the most common mutations in strains resistant to RIF and INH. Keywords: Abbott RealTime MTB RIF/INH Resistance assay, M. tuberculosis, mutations