Genetic analysis of Mycobacterium abscessus reveals genomic diversity linked to global plasmid distribution

Genetic epidemiological analysis of mobile genetic elements, such as plasmids, has rarely been carried out in Mycobacterium abscessus, regardless of its usefulness in speculating the historical contact between bacteria. In this study, through whole genome sequencing analysis of M. abscessus isolated from the same patient, we identified three plasmids (pMAB625-1, pMAB625-2, and pMAB625-3) that were not found in the type strain ATCC 19977. We conducted an in silico analysis to investigate the distribution of previously identified plasmids, including the pMAB625 plasmids, in M. abscessus isolated from 462 clinical specimens worldwide. pMAB625-3 was the most prevalent plasmid, detected in 11.5% (53/462) of isolates. Furthermore, phylogenetic tree analysis revealed that these plasmids transferred beyond regions and subspecies and acquired unique mutations. These results indicate that the transmission of plasmids increases the genomic diversity in M. abscessus, and plasmid epidemiology is useful for estimating the historical contact between bacteria.