Critical role of in invasive capacity and intracellular survivability of .

UNLABELLED

enterica serovar Typhimurium, which is a common foodborne pathogen, causes both intestinal and systemic infections in hosts. has a complex pathogenic mechanism that involves invasive capacity and intracellular survivability, which hampers research on virulence of . The virulence of is primarily studied through pathogenicity islands (SPIs). However, there are also genes outside these SPIs that significantly impact virulence. Macrophage survival gene is positioned at a region independent of the SPIs and conserved in . However, there has been limited research on to date. This study aims to investigate the virulent function of to deepen our understanding of virulence. Proteomic and RT-qPCR analyses reveal that MsgA influences multiple metabolic pathways and the expression of SPIs. The depletion of led to the significantly reduced invasive capacity and intracellular survivability, and thus the decreased virulence of . In conclusion, our study suggests that MsgA is an important regulator that mainly regulates virulence. Further research into the function of MsgA will enhance the understanding of pathogenesis and promote the application of for medical treatment.

IMPORTANCE

enterica serovar Typhimurium is a common foodborne pathogen, it has a complex pathogenic mechanism that involves invasive capacity and intracellular survivability. The virulence of is primarily studied through its pathogenicity islands. In contrast, virulence genes located outside the pathogenicity islands (SPIs) have received less attention. Macrophage survival gene (MsgA) is positioned at a region independent of the SPIs and conserved in . Our research indicates that MsgA is a novel global regulator influencing the metabolic pathways and SPIs. Further research into the function of MsgA will enhance the understanding of pathogenesis and promote the application of for medical treatment.