Adhesive mechanism of different Salmonella fimbrial adhesins.

Salmonellosis is a serious threat to human and animal health. Salmonella adhesion to the host cell is an initial and most crucial step in the pathogenesis of salmonellosis. Many factors are involved in the adhesion process of Salmonella infection. Fimbriae are one of the most important factors in the adhesion of Salmonella. The Salmonella fimbriae are assembled in three types of assembly pathways: chaperon-usher, nucleation-precipitation, and type IV fimbriae. These assembly pathways lead to multiple types of fimbriae. Salmonella fimbriae bind to host cell receptors to initiate adhesion. So far, many receptors have been identified, such as Toll-like receptors. However, several receptors that may be involved in the adhesive mechanism of Salmonella fimbriae are still un-identified. This review aimed to summarize the types of Salmonella fimbriae produced by different assembly pathways and their role in adhesion. It also enlisted previously discovered receptors involved in adhesion. This review might help readers to develop a comprehensive understanding of Salmonella fimbriae, their role in adhesion, and recently developed strategies to counter Salmonella infection.