Mycobacterium tuberculosis borderline rpoB mutations: emerging from the unknown

Rifampicin drives the efficacy of the current first-line treatment regimen for tuberculosis (TB) [1]. Mutations in the rpoB gene cause rifampicin resistance (RR) of varying levels. Common mutations typically confer high-level, "high-confidence" resistance, providing a selective advantage to Mycobacterium tuberculosis during treatment at low fitness cost [2]. Growth-based phenotypic drug-susceptibility testing (pDST) is very reliable for high-confidence mutations. Mutations conferring low-level resistance at high fitness cost are easily lost during primary culture or will cause phenotypically false-susceptible results if not given enough time for growth, especially with the widely used automated MGIT 960 DST [3]. Due to disagreement on their significance, such rpoB mutations were called "disputed".

Source: European Respiratory Journal - September 2, 2021 Category: Respiratory Medicine Authors: Van Deun, A., Decroo, T., Aung, K. J. M., Hossain, M. A., Gumusboga, M., De Rijk, W. B., Tahseen, S., de Jong, B. C., Rigouts, L. Tags: Original Articles: Research letters Source Type: research