Salmonella is the main food-borne pathogen that causes food poisoning and gastroenteritis in human and ani-mals .The type III secretion system in Salmonella has played an important role in the invasion of host cell .In recent years ,the research of the composition ,assembly and related pathogenesis of Salmonella T3SS have made some progress .This article re-views the composition and assembly of Salmonella type III secretion system ,which could provide further study the pathogene-sis of Salmonella and also the new strategies and methods toward the treatment and prevention of Salmonella infections .

Clustered regularly interspaced short palindromic repeats (CRISPR) is an acquired immune system existing in archaea and bacteria with the long-term process of evolutionary.CRISPR/Cas9 gene editing system is a new type of gene editing technology developed based on the system.CRISPR/Cas9 is a more efficient method for gene targeting than the previous methods.It has been successfully applied for gene-modified of eukaryotes since 2012,but the reports about pathogenic microorgaisms are rarely.Here,the research progress in the structure,mechanism of CRISPR/Cas9 system and its applications on pathogenic microorgaisms is reviewed.