Genomic features and virulence characteristics of a rare Burkholderia thailandensis strain causing human infection.

Introduction. Burkholderia thailandensis is a clinically rare opportunistic pathogen in the genus Burkholderia, and the genomic features and virulence characteristics of B. thailandensis strains that cause human infection remain unclear.Gap Statement. B. thailandensis strains with different virulence induce different host innate immune responses in vitro.Aim. This work aimed to understand the sequence diversity, phylogenetic relationship, and virulence of B. thailandensis BPM causing human infection.Methodology. The comparative molecular and genomic analyses, and mouse infection studies were applied to analyse the virulence and genomic features of B. thailandensis BPM originating from China.Results. The whole genome sequence analysis showed that the genomes of BPM and other avirulent B. thailandensis strains were broadly similar, comprising two highly syntenic chromosomes with comparable numbers of coding regions (CDs), protein family distributions, and horizontally acquired genomic islands. By examining species-specific genomic regions, we obtained molecular explanations for previously known differences in virulence and discovered the potential specific virulence-associated genes of BPM, which likely work together to confer the virulence of BPM. Significantly reduced LD₅₀ and survival rates during mouse infection experiments were found in BPM compared to the avirulent B. thailandensis E264 (BtE264).Conclusion. Taken together, the results of this study provide basic information on the genomic features and virulence characteristics of the virulent B. thailandensis strain BPM, which is helpful for understanding its evolution as it relates to pathogenesis and environmental adaptability.