title: Burkholderia pseudomallei transcriptional adaptation in macrophages.
abstract: BACKGROUND
  Burkholderia pseudomallei is a facultative intracellular pathogen of phagocytic and non-phagocytic cells. How the bacterium interacts with host macrophage cells is still not well understood and is critical to appreciate the strategies used by this bacterium to survive and how intracellular survival leads to disease manifestation.
  
  
  RESULTS
  Here we report the expression profile of intracellular B. pseudomallei following infection of human macrophage-like U937 cells. During intracellular growth over the 6 h infection period, approximately 22 % of the B. pseudomallei genome showed significant transcriptional adaptation. B. pseudomallei adapted rapidly to the intracellular environment by down-regulating numerous genes involved in metabolism, cell envelope, motility, replication, amino acid and ion transport system and regulatory function pathways. Reduced expression in catabolic and housekeeping genes suggested lower energy requirement and growth arrest during macrophage infection, while expression of genes encoding anaerobic metabolism functions were up regulated. However, whilst the type VI secretion system was up regulated, expression of many known virulence factors was not significantly modulated over the 6hours of infection.
  
  
  CONCLUSIONS
  The transcriptome profile described here provides the first comprehensive view of how B. pseudomallei survives within host cells and will help identify potential virulence factors and proteins that are important for the survival and growth of B. pseudomallei within human cells.
authors: School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, 43600, Malaysia.
authors: Sylvia
authors: S
authors: Chieng
authors: Laura
authors: L
authors: Carreto
authors: Sheila
authors: S
authors: Nathan
mesh_terms: D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D016957:Burkholderia pseudomallei / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015536:Down-Regulation; D020869:Gene Expression Profiling; D006801:Humans; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology; D020411:Oligonucleotide Array Sequence Analysis; D012329:RNA, Bacterial / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D059467:Transcriptome; D020298:U937 Cells; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria