Transcriptomes of 35000HP, ΔcpxA, ΔcpxR mutant strains of Haemophilus ducreyi in mid-log, transition, and stationary phase. [Haemophilus] ducreyi

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. Overall design: RNA of Haemophilus ducreyi wildtype, cpxA and cpxR mutants were collected at mid-log, transition, and stationary phases of growth, in quadruplicate.