Genomic molecular signatures determined characterization of Mycolicibacterium gossypii sp. nov., a fast-growing mycobacterial species isolated from cotton field soil

A Gram-positive, acid-fast and rapidly growing rod, designated S2-37( T), that could form yellowish colonies was isolated from one soil sample collected from cotton cropping field located in the Xinjiang region of China. Genomic analyses indicated that strain S2-37( T) harbored T7SS secretion system and was very likely able to produce mycolic acid, which were typical features of pathogenetic mycobacterial species. 16S rRNA-directed phylogenetic analysis referred that strain S2-37( T) was closely related to bacterial species belonging to the genus Mycolicibacterium, which was further confirmed by pan-genome phylogenetic analysis. Digital DNA-DNA hybridization and the average nucleotide identity presented that strain S2-37( T) displayed the highest values of 39.1% (35.7-42.6%) and 81.28% with M. litorale CGMCC 4.5724( T), respectively. And characterization of conserved molecular signatures further supported the taxonomic position of strain S2-37( T) belonging to the genus Mycolicibacterium. The main fatty acids were identified as C-16:0, C-18:0, C-20:3 omega 3 and C-22:6 omega 3. In addition, polar lipids profile was mainly composed of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. Phylogenetic analyses, distinct fatty aids and antimicrobial resistance profiles indicated that strain S2-37( T) represented genetically and phenotypically distinct from its closest phylogenetic neighbour, M. litorale CGMCC 4.5724( T). Here, we propose a novel species of the genus Mycolicibacterium: Mycolicibacterium gossypii sp. nov. with the type strain S2-37( T) (= JCM 34327( T) = CGMCC 1.18817( T)).