Deletion of M. abscessus hflX confers macrolide-lincosamide sensitivity. (A–C) Ten-fold serial dilutions of M. abscessus ATCC 19977, ΔMab_hflX, ΔMab_whiB7, ΔMab_erm41, ΔMab_hflX/ΔMab_erm41, ΔMab_1846, ΔMab_2355, and the indicated complementing strains were grown to A600 of 0.7 and spotted on Middlebrook 7H10 OADC containing 20 μg/mL erythromycin, 1 μg/mL clarithromycin, 10 μg/mL azithromycin, or 400 μg/mL clindamycin.