Global prevalence of strains with recombinant genes (Rec-Mas) horizontally transferred from : two major types, dominant circulating clone 7 and MLST ST46 sequence type.

UNLABELLED

is a group of emerging antimicrobial-resistant nontuberculous mycobacteria that causes severe lung disease in infected patients globally. Recently, molecular epidemiology studies have indicated that horizontal gene transfer (HGT) events in the gene are prevalent between subspecies. To determine the global prevalence of strains subjected to HGT, we performed phylogenetic inference using a 711-bp sequence extracted from 1,786 . isolates for which the whole-genome sequence was publicly available. Our data showed that a total of 74 isolates (4.1%) from 1,786 strains are subject to HGT, which is more prevalent than strains with HGT (19 isolates from 1,786, 1.1%). Most of these (69 isolates) belong to two major groups of , of which the gene is horizontally transferred from (Rec-mas), dominant circulating clone 7 (DCC7) (44 isolates) and ST46 type by multilocus sequence typing (25 isolates). The Rec-mas strains of the two groups have distinct geographical patient distributions, of which the former is mainly distributed in the United States, while the latter is prevalent in Asia. Our further genome-based analysis indicated that the ST46 type is a novel DCC candidate of that is responsible for dissemination between noncystic fibrosis patients in Asia. In conclusion, our global phylogenetic analysis revealed two major Rec-mas clones with distinct geographical distributions, namely, DCC7 and ST46. This study provides insights into the genetic clustering and person-to-person transmission of globally dominant and area-specific strains harboring the HGT gene.

IMPORTANCE

Horizontal gene transfer (HGT) events play a pivotal role in the evolution of 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 could also compromise differentiation between strains of . Here, for the first time, using 1,786 genome sequences, we evaluated the global prevalence of strains subjected to HGT. We found a greater prevalence of subjected to HGT than to those subjected to HGT, which is mainly due to two Rec-mas clones, dominant circulating clone 7 and ST46, which are responsible for dissemination between non-CF patients in Asia. Our data highlight the importance of HGT in the evolution of , particularly , into virulent DCC clones.