Mycobacterium paragordonae sp. nov., a slowly growing, scotochromogenic species closely related to Mycobacterium gordonae

Abstract

A previously undescribed, slowly growing, scotochromogenic mycobacterial strain (49061(T)) was isolated from a patient with pulmonary infections during the hsp65-sequence-based identification of Korean clinical isolates. Its 16S rRNA gene sequence was unique and the phylogenetic analysis based on 16S rRNA gene sequence (1393 bp) placed the organism into the slow-growing Mycobacterium group close to Mycobacterium gordonae (99.0 % sequence similarity). Growth characteristics and acid-fastness also supported the placement of this species into the genus Mycobacterium. Phenotypically, this strain was generally similar to Mycobacterium gordonae; however, of particular interest, the optimal growth temperature of strain 49061(T) was 25-30 °C, and it was not able to grow at 37 °C on 7H10 agar slants. Unique MALDI-TOF MS profiles of lipids, phylogenetic analysis based on another two gene sequences (hsp65 and rpoB) and a low DNA-DNA relatedness (46.52±0.7) strongly supported the taxonomic status of this strain as a representative of a distinct species from M. gordonae. It was concluded that the strain represents a novel species for which the name Mycobacterium paragordonae is proposed with the type strain 49061(T) ( = JCM 18565(T) = KCTC 29126(T)).