The Genome Sequence of ‘<i>Mycobacterium massiliense</i>’ Strain CIP 108297 Suggests the Independent Taxonomic Status of the <i>Mycobacterium abscessus</i> Complex at the Subspecies Level

<div><p>Members of the <i>Mycobacterium abscessus</i> complex are rapidly growing mycobacteria that are emerging as human pathogens. The <i>M. abscessus</i> complex was previously composed of three species, namely <i>M. abscessus</i><i>sensu stricto</i>, ‘<i>M. massiliense</i>’, and ‘<i>M. bolletii</i>’. In 2011, ‘<i>M. massiliense</i>’ and ‘<i>M. bolletii</i>’ were united and reclassified as a single subspecies within <i>M. abscessus</i>: <i>M. abscessus</i> subsp. <i>bolletii</i>. However, the placement of ‘<i>M. massiliense</i>’ within the boundary of <i>M. abscessus</i> subsp. <i>bolletii</i> remains highly controversial with regard to clinical aspects. In this study, we revisited the taxonomic status of members of the <i>M. abscessus</i> complex based on comparative analysis of the whole-genome sequences of 53 strains. The genome sequence of the previous type strain of ‘<i>Mycobacterium massiliense</i>’ (CIP 108297) was determined using next-generation sequencing. The genome tree based on average nucleotide identity (ANI) values supported the differentiation of ‘<i>M. bolletii</i>’ and ‘<i>M. massiliense</i>’ at the subspecies level. The genome tree also clearly illustrated that ‘<i>M. bolletii</i>’ and ‘<i>M. massiliense</i>’ form a distinct phylogenetic clade within the radiation of the <i>M. abscessus</i> complex. The genomic distances observed in this study suggest that the current <i>M. abscessus</i> subsp. <i>bolletii</i> taxon should be divided into two subspecies, <i>M</i>. <i>abscessus</i> subsp. <i>massiliense</i> subsp. nov. and <i>M</i>. <i>abscessus</i> subsp. <i>bolletii</i>, to correspondingly accommodate the previously known ‘M. massiliense’ and ‘<i>M</i>. <i>bolletii</i>’ strains. </p>