A slow-growing, scotochromogenic mycobacterial strain (24T) was isolated from the sputum of a Chinese male human. Phylogenetic analysis using the 16S rRNA gene assigned strain 24T to the Mycobacterium gordonae complex, which includes Mycobacterium gordonae and Mycobacterium paragordonae. The phenotypic characteristics, unique mycolic acid profile and the results of phylogenetic analysis based on hsp65 and rpoB sequences strongly supported the taxonomic status of strain 24T as a representative of a species distinct from the other members of the M. gordonae complex. The genomic G+C content of strain 24T was 65.40mol%. Genomic comparisons showed that strain 24T and M. gordonae ATCC 14470T had an average nucleotide identity (ANI) value of 81.00 % and a DNA-DNA hybridization (DDH) value of 22.80 %, while the ANI and DDH values between strain 24Tand M. paragordonae 49 061T were 80.98 and 22.80 %, respectively. In terms of phylogenetic, phenotypic and chemotaxonomic features, strain 24T is distinguishable from its closest phylogenetic relatives and represents a novel species of the genus Mycobacterium, therefore the name Mycobacterium vicinigordonae sp. nov. is proposed. The type strain is 24T (=CMCC 93559T=DSM 105979T).
Keywords: Mycobacterium vicinigordonae; non-tuberculous mycobacteria; strain 24T; taxonomy.