[Advances in Salmonella pathogenicity island 2 type III secretion system - A review]

Salmonella is a Gram-negative facultative intracellular pathogen that can infect vast array of hosts and cause a series of diseases, sometimes even life-threatening systemic diseases. As an indispensable virulence determinant associated with the systemic infections, Salmonella pathogenicity island 2 (SPI2) encodes type III secretion system 2 (T3SS2) which is induced after invasion, and the T3SS2 secreted effectors are essential for Salmonella to survive and replicate inside various cell types. In recent years, this issue remains the focus of pathogenic research. This review focuses on the aspects of gene characterization of SPI2, regulation of SPI2 gene expression, the structure and assembly of T3SS2, the T3SS2 effectors and some vaccine candidates associated with T3SS2 to present the current understanding of Salmonella T3SS2.