Comparative population genomic analysis of Brevibacterium casei isolated from a tuberculosis patient.

Brevibacterium casei, previously considered as non-pathogenic to human host is now drawing attention due to its association with frequent infections in immunocompromised patients suffering from leukemia and HIV. Despite growing incidence of B. casei infections, limited number of genomes have been sequenced to date, this restricts our understanding on ge-nomic heterogeneity and the evolution of pathogenic B.casei strains. Here, we sequenced the whole genome of B. casei HOS 100 strain isolated from a tuberculosis patient. The genome size was 3.8 Mb and G + C content 67.94%. Present study estimates the genetic diversity and factors effecting evolutionary dynamics of B. casei strains. Phylogenomic and population genomic analyses reveal that recombination, horizontal gene transfer, and the ongoing expansion of the pangenome contribute to the genetic diversity and potential emergence of genetically distinct B. casei strains.