LAUSR

We performed bedaquiline broth microdilution susceptibility testing using Clinical and Laboratory Standards Institute (CLSI) guidelines on 104 nonduplicate isolates of Mycobacterium abscessus complex [M. abscessus subsp. abscessus (76); M. abscessus subsp. ABSTRACT We performed bedaquiline broth microdilution susceptibility testing using Clinical and Laboratory Standards Institute (CLSI) guidelines on 104 nonduplicate isolates of Mycobacterium abscessus complex [M. abscessus subsp. abscessus (76); M. abscessus subsp. massiliense (10); M. abscessus subsp. bolletii (2); and M. abscessus subsp. abscessus-M. abscessus subsp. massiliense hybrid, i.e., M. abscessus subsp. abscessus by rpoB gene and M. abscessus subsp. massiliense by erm(41) gene (16)]. All isolates from patients not known to have been on bedaquiline prior had MIC values of ≤0.25 μg/ml. The bedaquiline MIC50 value for all 76 isolates of M. abscessus subsp. abscessus and 16 isolates of M. abscessus subsp. abscessus-M. abscessus subsp. massiliense hybrid was 0.06 μg/ml. The MIC50 and MIC90 values for 10 isolates of M. abscessus subsp. massiliense were 0.12 μg/ml. Only two isolates of M. abscessus subsp. bolletii were tested with bedaquiline MICs of 0.06 μg/ml. Our study suggests that oral bedaquiline may have potential use in the treatment of disease caused by the M. abscessus complex. Combination therapy with other agents (imipenem, cefoxitin, amikacin, and/or tigecycline) is recommended.