Mycobacterium brisbanense is a member of Mycobacterium fortuitum third biovariant complex, which includes rapidly growing Mycobacterium spp. that normally inhabit soil, dust and water, and can sometimes cause respiratory tract infections in humans. We present the first whole-genome analysis of M. brisbanense UM_WWY which was isolated from a 70-year-old Malaysian patient. Molecular phylogenetic analyses confirmed the identification of this strain as M. brisbanense and showed that it has an unusually large genome compared with related mycobacteria. The large genome size of M. brisbanense UM_WWY (~7.7Mbp) is consistent with further findings that this strain has a highly variable genome structure that contains many putative horizontally transferred genomic islands and prophage. Comparative analysis showed that M. brisbanense UM_WWY is the only Mycobacterium species that possesses a complete set of genes encoding enzymes involved in the urea cycle, suggesting that this soil bacterium is able to synthesize urea for use as plant fertilizers. It is likely that M. brisbanense UM_WWY is adapted to live in soil as its primary habitat since the genome contains many genes associated with nitrogen metabolism. Nevertheless, a large number of predicted virulence genes were identified in M. brisbanense UM_WWY that are mostly shared with well-studied mycobacterial pathogens such as Mycobacterium tuberculosis and Mycobacterium abscessus. These findings are consistent with the role of M. brisbanense as an opportunistic pathogen of humans. The whole-genome study of UM_WWY has provided the basis for future work of M. brisbanense.
Mycobacterium cosmeticum is a nontuberculous Mycobacterium recovered from different water sources including household potable water and water collected at nail salon. Individual cases of this bacterium have been reported to be associated with gastrointestinal tract infections. Here we present the first whole-genome study and comparative analysis of two new clinically-derived Mycobacterium sp. UM_RHS (referred as UM_RHS after this) and Mycobacterium sp. UM_NYF (referred as UM_NYF after this) isolated from patients in Indonesia and Malaysia respectively to have a better understanding of the biological characteristic of these isolates. Both strains are likely Mycobacterium cosmeticum as supported by the evidence from molecular phylogenetic, comparative genomic and Average Nucleotide Identity (ANI) analyses. We found the presence of a considerably large number of putative virulence genes in the genomes of UM_RHS and UM_NYF. Interestingly, we also found a horizontally transferred genomic island carrying a putative dsz operon proposing that they may have potential to perform biodesulfization of dibenzothiophene (DBT) that may be effective in cost reduction and air pollution during fuel combustion. This comparative study may provide new insights into M. cosmeticum and serve as an important reference for future functional studies of this bacterial species.
The genome of Mycobacterium massiliense M172, isolated from a human sputum sample, was sequenced using Illumina GA IIX technology and found to contain 5,204,460 bp, including putative genes for virulence and antibiotic resistance as well as a 92-kb genomic region most likely to correspond to a mycobacteriophage.