[Bacterial secretion systems: their function and contribution to disease process].

Bacterial pathogens possesses certain secretion systems to maintain their homeostasis and to exert full virulence. Currently, two translocons including Sec and Tat, and 7 secretion systems are found in Gram-positive and -negative bacteria. Some virulence factors, which are referred to as effectors, are directly translocated into the host cell via an injection apparatus, i.e., the type III secretion system. Thus, characterization of secretion systems and their delivered proteins into extracellular milieus is required for understanding of strategies of bacterial pathogens.