Project description:Bacterial transcriptomes are dynamic, context-specific and condition-dependent. Infection by the soil bacterium, Burkholderia pseudomallei, causes melioidosis, an often fatal infectious disease of humans and animals. Possessing a large multi-chromosomal genome, B. pseudomallei is able to persist and survive in a multitude of environments. To obtain a comprehensive overview of B. pseudomallei expressed transcripts, we initiated whole-genome transcriptome profiling covering a broad spectrum of conditions and exposures – a so-called “condition compendium”. Using the compendium, we confirmed many previously-annotated genes and operons, and also identified hundreds of novel transcripts including anti-sense transcripts and non-coding RNAs. By systematically examining genes exhibiting highly similar expression patterns, we ascribed putative functions to previously uncharacterized genes, and identified novel regulatory elements controlling these expression patterns. We also used the compendium to elucidate candidate virulence pathways associated with quorum-sensing and infection in mice. Our study showcases the power of a B. pseudomallei condition compendium as a valuable resource for understanding microbial physiology and the pathogenesis of melioidosis.
Project description:Melioidosis is a neglected tropical disease caused by the Gram-negative bacterium Burkholderia pseudomallei. It is widespread in Southeast Asia and under-reported across tropical regions worldwide. Patients present with a range of clinical syndromes including sepsis, pneumonia and focal abscesses, with a mortality rate of 40% in hospitalized patients in Thailand. Up to two-thirds of patients with melioidosis have diabetes mellitus. In this experiment we sought to characterize pathways activated by whole killed B. pseudomallei bacteria and by three vaccine candidate proteins from B. pseudomallei, BPSL2520 (uncharacterized protein), BPSS1525 (BopE) and BPSL2096 (AhpC) in patients with diabetes and acute melioidosis.
Project description:Burkholderia pseudomallei is the causative agent of melioidosis a disease endemic in South-East Asia and Northern Australia. The mortality rates in these areas are unacceptably high even with antibiotic treatment, attributed to intrinsic and acquired resistance of B. pseudomallei to antibiotics. With very few options for therapeutics there is an urgent requirement to identify anti-bacterial targets for the development of novel, effective treatments. In this study we examine the role and effect of ppiB on the proteome. Using LFQ analysis we show loss of ppiB has dramatic effect on the Burkholderia pseudomallei proteome.
Project description:Bacterial transcriptomes are dynamic, context-specific and condition-dependent. Infection by the soil bacterium, Burkholderia pseudomallei, causes melioidosis, an often fatal infectious disease of humans and animals. Possessing a large multi-chromosomal genome, B. pseudomallei is able to persist and survive in a multitude of environments. To obtain a comprehensive overview of B. pseudomallei expressed transcripts, we initiated whole-genome transcriptome profiling covering a broad spectrum of conditions and exposures M-bM-^@M-^S a so-called M-bM-^@M-^\condition compendiumM-bM-^@M-^]. Using the compendium, we confirmed many previously-annotated genes and operons, and also identified hundreds of novel transcripts including anti-sense transcripts and non-coding RNAs. By systematically examining genes exhibiting highly similar expression patterns, we ascribed putative functions to previously uncharacterized genes, and identified novel regulatory elements controlling these expression patterns. We also used the compendium to elucidate candidate virulence pathways associated with quorum-sensing and infection in mice. Our study showcases the power of a B. pseudomallei condition compendium as a valuable resource for understanding microbial physiology and the pathogenesis of melioidosis. The transcriptome profiles of Bp exposed to 82 conditions were captured using a custom-designed tiling microarray and compiled into a compendium revealing novel genomic features and co-expression network.
Project description:Many microbial pathogens express specific virulence traits at distinct growth phases. To investigate the molecular pathways linking bacterial growth to pathogenicity, we characterized the genome-wide growth transcriptome of the tropical pathogen Burkholderia pseudomallei (Bp), the causative agent of melioidosis. Using fine-scale sampling, approximately 17% of all Bp genes were found to display regulated expression during growth, manifested primarily as discrete waves of gene expression tightly associated with distinct growth phases and transition points. A functional curation of these clusters provided evidence of a global ‘just-in-time’ production strategy to ensure the synthesis of molecular constituents only when needed. We observed regulation of multiple virulence factors at all growth phases, and by analyzing the early-phase transcriptome data, we identified and experimentally validated serC as a novel virulence factor in mice. Immunization of mice with serC-disrupted Bp also conferred protection against subsequent challenges with different wild-type Bp strains, demonstrating the potential utility of the serC mutant as an attenuated vaccine. We found a significant bias in early phase genes on Chromosome 1, supporting its proposed role as the ancestral Burkholderia chromosome, and utilized a chromosomally ordered co-expression metric to define ~100 putative operons throughout the Bp genome. These results extend our knowledge of virulence pathways in Bp, and suggest that molecular events at all growth phases, including early phase, are likely to play important roles in microbial pathogenicity." Keywords: Time Series Comparison Bp (K96243)