YaeB, Expressed in Response to the Acidic pH in Macrophages, Promotes Intracellular Replication and Virulence of Typhimurium.

serovar Typhimurium is a facultative intracellular pathogen that infects humans and animals. Survival and growth in host macrophages represents a crucial step for . Typhimurium virulence. Many genes that are essential for . Typhimurium proliferation in macrophages and associated with virulence are highly expressed during the intracellular lifecycle. , which encodes an RNA methyltransferase, is also upregulated during . Typhimurium growth in macrophages. However, the involvement of YaeB in . Typhimurium pathogenicity is still unclear. In this study, we investigated the role of YaeB in . Typhimurium virulence. Deletion of significantly impaired . Typhimurium growth in macrophages and virulence in mice. The effect of on pathogenicity was related to its activation of , a phosphate (P)-specific transport system that is verified here to be important for bacterial replication and virulence. Moreover, qRT-PCR data showed YaeB was induced by the acidic pH inside macrophages, and the acidic pH passed to YeaB through inhibiting global regulator histone-like nucleoid structuring (H-NS) which confirmed in this study can repress the expression of . Overall, these findings identified a new virulence regulatory network involving and provided valuable insights to the mechanisms through which acidic pH and low P regulate virulence.