Accession Number:

ADA443161

Title:

Bacterial Genome Adaptation to Niches: Divergence of the Potential Virulence Genes in Three Burkholderia Species of Different Survival Strategies

Descriptive Note:

Journal article

Corporate Author:

INSTITUTE FOR GENOMIC RESEARCH ROCKVILLE MD

Report Date:

2005-12-01

Pagination or Media Count:

14.0

Abstract:

Two closely related species -- Burkholderia mallei Bm and Burkholderia pseudomallei Bp -- are serious human health hazards and are potential bio-warfare agents, whereas another closely related species -- Burkholderia thailandensis Bt -- is a non-pathogenic saprophyte. To investigate the genomic factors resulting in such a dramatic difference, we first identified the Bm genes responsive to the mouse environment, and then examined the divergence of these genes in Bp and Bt. RESULTS The genes down-expressed, which largely encode cell growth-related proteins, are conserved well in all three species, whereas those up-expressed, which include potential virulence genes, are less well conserved or absent notably in Bt. However, a substantial number of up-expressed genes is still conserved in Bt. Bm and Bp further diverged from each other in a small number of genes resulting from unit number changes in simple sequence repeats ssr in the homologs. CONCLUSIONS Our data suggest that divergent evolution of a small set of genes, rather than acquisition or loss of pathogenic islands, is associated with the development of different life styles in these bacteria of similar genomic contents. Further divergence between Bm and Bp mediated by ssr changes may reflect different adaptive processes of Bm and Bp fine-tuning into their host environments.

Subject Categories:

  • Microbiology
  • Chemical, Biological and Radiological Warfare

Distribution Statement:

APPROVED FOR PUBLIC RELEASE