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

Pilar Ruiz; Manuel Causse; Manuel Vaquero; Juan Bautista Gutierrez; Manuel Casal

doi:10.2147/IDR.S147272

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

Infect Drug Resist. 2017 Dec 6:10:463-467. doi: 10.2147/IDR.S147272. eCollection 2017.

Authors

Pilar Ruiz¹, Manuel Causse², Manuel Vaquero¹, Juan Bautista Gutierrez^{1

2}, Manuel Casal^{1

2}

Affiliations

¹ Mycobacteria Reference Center, Department of Microbiology, Faculty of Medicine and Nursing, University of Córdoba, Córdoba, Spain.
² Microbiology 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.