Mycobacterium vicinigordonae sp. nov., a slow- growing scotochromogenic species isolated from sputum

A slow-growing, scotochromogenic mycobacterial strain (24(T)) was isolated from the sputum of a Chinese male human. Phylogenetic analysis using the 16S rRNA gene assigned strain 24(T) 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 24(T) was 65.40mol%. Genomic comparisons showed that strain 24(T) and M. gordonae ATCC 14470(T) 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 24(T) and M. paragordonae 49061(T) were 80.98 and 22.80 %, respectively. In terms of phylogenetic, phenotypic and chemotaxonomic features, strain 24(T) 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 24(T) (=CMCC 93559(T)=DSM 105979(T)).

Automated summary

A novel slow-growing scotochromogenic mycobacterial strain (24(T)) isolated from a Chinese male human's sputum was identified through phylogenetic analysis and genomic comparisons, and proposed to be named as Mycobacterium vicinigordonae sp. nov. based on its distinct phylogenetic, phenotypic, and chemotaxonomic features.