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, 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 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 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 displayed the highest values of 39.1% (35.7-42.6%) and 81.28% with M. litorale CGMCC 4.5724, respectively. And characterization of conserved molecular signatures further supported the taxonomic position of strain S2-37 belonging to the genus Mycolicibacterium. The main fatty acids were identified as C, C, Cω3 and Cω3. 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 represented genetically and phenotypically distinct from its closest phylogenetic neighbour, M. litorale CGMCC 4.5724. Here, we propose a novel species of the genus Mycolicibacterium: Mycolicibacterium gossypii sp. nov. with the type strain S2-37 (= JCM 34327 = CGMCC 1.18817).