rpoB horizontal gene transfer mycobacterium abscessus

Horizontal gene transfer events play a pivotal role in the evolution of the Mycobacterium abscessus complex (MABC) into dominant circulating clones (DCCs), which is capable of causing patient-to-patient transmission. In particular, HGT of the rpoB gene between strains of different subspecies of MABC could also compromise differentiation between strains of MABC. Here, for the first time, using 1786 MABC genome sequences, we evaluated the global prevalence of MABC strains subjected to rpoB HGT. We found a greater prevalence of MABCs subjected to rpoB HGT than to those subjected to hsp65 HGT, which is mainly due to two Rec-mas clones, DCC7 and ST46, which are responsible for dissemination between non-CF patients in Asia. Our data highlight the importance of rpoB HGT in the evolution of MABC, particularly M. massiliense, into virulent DCC clones.