Rifabutin Is Inactivated by Mycobacterium abscessus Arr

Abstract

<i>Mycobacterium abscessus</i> exhibits Arr (ADP-ribosyltransferase)-dependent rifampin resistance. In apparent contrast, rifabutin (RBT) has demonstrated promising activity in <i>M. abscessus</i> infection models, implying that RBT might not be inactivated by Arr. RBT susceptibility testing of <i>M. abscessus</i><i>Δarr</i> revealed a strongly decreased MIC. Our findings suggest that the efficacy of RBT might be enhanced by rendering RBT resilient to Arr-dependent modification or by blocking <i>M. abscessus</i> Arr activity.