Discrepancies in isoniazid susceptibility profiles: Bactec MGIT 960-resistant but GenoType MTBDR<i>plus</i>-susceptible <i>Mycobacterium tuberculosis</i> strains in Hunan, China.

ABSTRACT: Discordant drug susceptibility testing (DST) results between the Bactec MGIT 960 system (MGIT) and the GenoType MTBDRplus assay (MTBDRplus) for isoniazid (INH) complicate clinical decision-making. In this study, we performed minimum inhibitory concentration (MIC) assays and whole-genome sequencing (WGS) on 53 Mycobacterium tuberculosis strains identified as INH-resistant by MGIT but INH-susceptible by MTBDRplus. The variants conferring INH resistance were evaluated by the WHO mutation catalogue. Our results showed that only five strains carried variants classified as "associated with resistance" (Group 1/2), including katG Trp39STOP, katG Ser315Asn, inhA -154G>A, and inhA Ser94Ala. In addition, 44 strains carried 70 variants classifie

SUBMITTER: Chen Z 

PROVIDER: S-EPMC12584712 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature