Project description:To potentially understand how H. ducreyi responds to membrane stress, here we defined RpoE-dependent genes using RNA-Seq. We identified 180 RpoE-dependent genes, of which 98% were upregulated; a major set of these genes encodes homologues of envelope maintenance and repair factors. We also identified and validated a putative RpoE promoter consensus sequence, which was enriched in the majority of RpoE-dependent targets. Comparison of RpoE-dependent genes to those controlled by CpxR showed that each transcription factor regulated a distinct set of genes. Given that RpoE activated a large number of genes encoding envelope maintenance and repair factors and CpxRA represses genes encoding envelope-localized proteins, these data suggest that RpoE and CpxRA appear to play distinct yet complementary roles in regulating envelope homeostasis in H. ducreyi. RNA of Haemophilus ducreyi 35000HP wild-type strain containing a rpoE inducible plasmid and wild-type strain containing a control plasmid were collected at 0 minutes, 5 minutes, and 10 minutes after induction in quadruplicate.
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.
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: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.