Deletion of the Transcriptional Regulator MucR in Affects Stress Responses and Bacterial Virulence.

The transcriptional regulator MucR is related to normal growth, stress responses and virulence, and affects the expression of various virulence-related genes in smooth-type strains. However, the function of MucR in the rough-type remains unknown. In this study, we discovered that MucR protein was involved in resistance to heat stress, iron-limitation, and various antibiotics in . . In addition, the expression level of various bacterial flagellum-related genes was altered in mutant strain. Deletion of this transcriptional regulator in significantly affected virulence in RAW264.7 macrophage and mice infection model. To gain insight into the genetic basis for distinctive phenotypic properties exhibited by mutant strain, RNA-seq was performed and the result showed that various genes involved in translation, ribosomal structure and biogenesis, signal transduction mechanisms, energy production, and conversion were significantly differently expressed in Δ strain. Overall, these studies have not only discovered the phenotype of mutant strain but also preliminarily uncovered the molecular mechanism between the transcriptional regulator MucR, stress response and bacterial virulence in . .