Project description:To better understand the role of the (p)ppGpp-mediated stringent response in control of H. ducreyi virulence determinants, here we defined genes potentially regulated by either (p)ppGpp or DksA by using RNA-seq. We were able to show that loss of either (p)ppGpp or DksA resulted in dysregulation of multiple genes including several known virulence determinants. We also show that loss of (p)ppGpp or DksA resulted in differential expression of putative H. ducreyi small RNAs. RNA of Haemophilus ducreyi wildtype, relAspoT and dksA mutants were collected at mid-log, transition, and stationary phases of growth, in quadruplicate using stranded RNA -seq.
Project description:To better understand the role of H. ducreyi CpxRA in controlling virulence determinants, here we defined genes potentially regulated by CpxRA by using RNA-Seq. Activation of CpxR by deletion of cpxA repressed nearly 70% of its targets, including seven established virulence determinants. Inactivation of CpxR by deletion of cpxR differentially regulated few genes and increased the expression of one virulence determinant. We identified a CpxR binding motif that was enriched in downregulated but not upregulated targets. These data reinforce the hypothesis that CpxA phosphatase activity plays a critical role in controlling H. ducreyi virulence in vivo. Characterization of the downregulated genes may offer new insights into pathogenesis. RNA of Haemophilus ducreyi wildtype, cpxA and cpxR mutants were collected at mid-log, transition, and stationary phases of growth, in quadruplicate.
Project description:The goal of this study was to compare the global trascription profile of a Haemophilus ducreyi hfq deletion mutant to that of the wild type parental strain.
Project description:The goal of this study was to compare the global trascription profile of a Haemophilus ducreyi fis deletion mutant to that of the wild type parental strain.
Project description:Comparative analysis of the global gene expression of a Haemophilus ducreyi 35000HP cpxA deletion mutant relative to the wild type strain
Project description:To better understand the molecular mechanisms underlying Haemophilus ducreyi infection in humans, here we determined the transcriptional profile of H. ducreyi in human lesions using RNA-Seq and compared it to that of in vitro growth. We were able to show that the in vivo transcriptome did not resemble that of in vitro growth. Compared to the inoculum, H. ducreyi harvested from pustules differentially expressed ~120 genes, of which 68 were upregulated. A large proportion of the upregulated genes encoded homologs of proteins involved in nutrient transport, alternative carbon pathways, growth arrest response, heat shock response, and DNA recombination. H. ducreyi upregulated few genes or operons (hgbA, flp-tad, and lspB-lspA2) required for human infection; expression of these genes is known to increase under nutrient stress. Homologs of several genes involved in anaerobic metabolism and ascorbate utilization were upregulated in vivo, suggesting that the organism is adjusting its metabolism to anaerobiosis in vivo. RNA from Haemophilus ducreyi infected pustules were collected from four volunteers and performed RNA-Seq.
Project description:To better understand the molecular mechanisms underlying Haemophilus ducreyi infection in humans, here we determined the transcriptional profile of H. ducreyi in human lesions using RNA-Seq and compared it to that of in vitro growth. We were able to show that the in vivo transcriptome did not resemble that of in vitro growth. Compared to the inoculum, H. ducreyi harvested from pustules differentially expressed ~120 genes, of which 68 were upregulated. A large proportion of the upregulated genes encoded homologs of proteins involved in nutrient transport, alternative carbon pathways, growth arrest response, heat shock response, and DNA recombination. H. ducreyi upregulated few genes or operons (hgbA, flp-tad, and lspB-lspA2) required for human infection; expression of these genes is known to increase under nutrient stress. Homologs of several genes involved in anaerobic metabolism and ascorbate utilization were upregulated in vivo, suggesting that the organism is adjusting its metabolism to anaerobiosis in vivo.