Dataset Information

Genome-Wide Mapping of Growth Regulated Genes in Burkholderia pseudomallei

ABSTRACT: 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)

ORGANISM(S): Burkholderia pseudomallei K96243

PROVIDER: GSE5495 | GEO | 2006/10/01

SECONDARY ACCESSION(S): PRJNA96135

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Unicellular algae, termed phytoplankton, greatly impact the marine environment by serving as the basis of marine food webs and by playing central roles in biogeochemical cycling of elements. The interactions between phytoplankton and heterotrophic bacteria affect the fitness of both partners. It is becoming increasingly understood that metabolic exchange determines the nature of such interactions, but the underlying molecular mechanisms remain underexplored. Here, we investigated the molecular and metabolic basis for the bacterial lifestyle switch, from coexistence to pathogenicity, in Sulfitobacter D7 during interactions with Emiliania huxleyi, a cosmopolitan bloom-forming phytoplankter. The interaction displays two distinct phases: first, there is a coexisting phase in which the alga grows exponentially and the bacterium grows as well. The interaction shifts to pathogenic when the virulence of Sulfitobacter D7 towards E. huxleyi is invoked upon exposure to high concentrations of algal dimethylsulfoniopropionate (DMSP), which occurs when the algae reach stationary growth or when DMSP is applied exogenously to algae in exponential growth. We aimed to unravel the response of Sulfitobacter D7 to the pathogenicity-inducing compound, DMSP, and to different algae-derived infochemicals that affect the lifestyle of the bacterium. We grew Sulfitobacter D7 in conditioned media (CM) derived from algal cultures at the different growth phases, exponential and stationary (Exp-CM and Stat-CM, respectively), in which DMSP concentration is low and high, respectively. This enabled us to separate between different phases of the interaction with E. huxleyi, i.e., Exp-CM representing the coexisting phase, and Stat-CM representing the pathogenic phase. An additional pathogenicity-inducing treatment was Exp-CM supplemented with 100 µM DMSP (herein Exp-CM+DMSP). This condition mimicked co-cultures to which we added DMSP exogenously and thus induced Sulfitobacter D7 pathogenicity, which lead to death of exponentially growing E. huxleyi. In order to identify bacterial genes that are specifically responsive to DMSP, and are not affected by other algae-derived factors, we grew Sulfitobacter D7 in defined minimal medium (MM), lacking algal metabolites, supplemented with 100 µM DMSP (herein MM+DMSP), and examined the transcriptional response. After 24 h of Sulfitobacter D7 growth in all 5 media, triplicates were taken for transcriptomic analysis. Altogether, this experimental design allowed to expand our understanding on the bacterial response to DMSP, algal infochemicals and which of these are essential for coexistence and pathogenicity.

Dataset Information

Genome-Wide Mapping of Growth Regulated Genes in Burkholderia pseudomallei

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets