Successful Treatment with a High-dose Rifampin-containing Regimen for Pulmonary Tuberculosis with a Disputed rpoB Mutation.

Mutations in the rpoB gene of Mycobacterium tuberculosis can result in resistance to rifampin. Among various mutations in the rpoB gene, some known as disputed rpoB mutations can cause low-level rifampin resistance. It has been suggested that a high-dose rifampin (20 mg/kg)-based regimen might be effective in treating tuberculosis (TB) caused by M. tuberculosis with disputed rpoB mutations exhibiting low-level resistance. We herein report the first two cases of pulmonary TB caused by M. tuberculosis with a disputed rpoB mutation (CTG511CCG) that showed successful treatment outcomes with a high-dose rifampin-based regimen.