Acquisition of bedaquiline and clofazimine resistance in association with a novel loss-of-function mutation in the pepQ gene during treatment of multidrug-resistant tuberculosis

November 12, 2025
Case Report
Melissa Richard-Greenblatt, Ruchika Bagga, Carla Duncan, Maxime J Billick, Howard Song, Natasha F Sabur, Vincent Escuyer, Karen Lam, Sarah K Brode
Pathogen:Mycobacterium tuberculosis
Infection Type:Multidrug-resistant tuberculosis
Pathogen Type:Bacteria

Summary

A patient with multidrug-resistant tuberculosis (MDR-TB) developed resistance to bedaquiline (BDQ) and clofazimine (CFZ) during treatment. The clinical presentation involved persistent Mycobacterium tuberculosis infection despite standard therapy. Diagnostic methods included whole-genome sequencing, which identified a novel loss-of-function mutation in the pepQ gene. This genetic change was directly associated with the acquired resistance to both BDQ and CFZ, highlighting a critical mechanism of treatment failure. The case underscores the importance of genomic surveillance in guiding effective MDR-TB management and understanding emerging resistance patterns. This finding offers new insights into the molecular basis of drug resistance in M. tuberculosis.

Key note: Novel mutations in genes like pepQ can lead to simultaneous resistance to multiple critical anti-TB drugs.

DOI: 10.1128/asmcr.00126-25