Abstract:

Objective To investigate the susceptibility of Mycobacterium avium complex to clofazimine， bedaquiline and delamanid，and therefore to explore the possibility of using these drugs to treat Mycobacterium avium complex lung disease. Methods The minimum inhibitory concentrations（MICs）of clofazimine，bedaquiline，and delamanid against 12 M. avium clinical isolates and 81 M. intracellulare clinical isolates were determined by using the microplate alamar blue assay（MABA）. Results The MIC50 and MIC90 of clofazimine against M. intracellulare were 0.25 μg/mL and 0.5 μg/mL，respectively. ECOFF of clofazimine against M. intracellulare was 0.5 μg/mL. The MIC50 and MIC90 of bedaquiline against M. intracellulare were 0.125 μg/mL and 0.25 μg/mL，respectively. ECOFF of bedaquiline against M. intracellulare was 0.25 μg/mL. The MICs of delamanid against 97.5%（79/81）of M. intra⁃ cellulare clinical isolates were ≥ 256 μg/mL. The MIC50 and MIC90 of clofazimine against M. avium were 0.25 μg/mL and 0.5 μg/mL，respectively. ECOFF of clofazimine against M. avium was 0.5 μg/mL. The MICs of bedaquiline against 75%（9/12）of M. avium clinical isolates were 0.0625 μg/mL；and the MICs of delamanid against 91.7% （11/12）of M. avium clinical isolates were > 4 μg/mL. Conclusions Clofazimine and bedaquiline showed acceptable in vitro activity against M. avium complex，and Delamanid has no effect on M. avium complex.

Key words:

mycobacterium avium complex, microbial sensitivity tests, clofazimine, bedaquiline, delamanid