Bimodal expression of Type 3 Secretion System 2 enables cooperative virulence among intracellular Salmonella Typhimurium.

ABSTRACT: The Type 3 Secretion System encoded by the Salmonella pathogenicity island 2 (SPI-2 T3SS) enables bacterial proliferation in Salmonella-containing vacuole and dissemination throughout the host. Despite its crucial importance, not all intracellular Salmonella express the SPI-2 T3SS. Using flow cytometry and microscopic analysis of bacteria within host cells, we demonstrate that both the injectisome as well as its effectors exhibit bimodal expression. This bimodality depended on activation of the transcriptional regulator SsrB by sensor kinase SsrA. Within an infected host cell, proliferation of bacteria not expressing the SPI-2 T3SS (SPI-2OFF) depended on SPI-2 T3SS-expressing bacteria (SPI-2ON), suggesting that all SPI-2 T3SS effectors necessary for Salmonella intracellular replication can

SUBMITTER: Pospisilova M 

PROVIDER: S-EPMC12677785 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature