English: FIGURE 1. Illustration on how Vibrio parahaemolyticus sense bile salts in the human gastrointestinal tract. Human ingest V. parahaemolyticus from contaminated seafood such as clams, shrimps and oysters. Upon ingestion, V. parahaemolyticus is exposed to bile salts in the gastrointestinal tract. VtrA and VtrC are two gene encoded proteins that is identified to be responsible for bile salt sensing. VtrA and VtrC will interact and form a protein complex on the surface of the membrane of the bacterial cell. This complex structure then binds to bile salts and triggers the cell to produce toxins. Upon binding of bile salts to the VtrA/VtrC complex, the cytoplasmic DNA binding domain of VtrA is activated which in turn induces VtrB to activate, resulting in the T3SS2 expression. T3SS2 virulence is secreted thus causing illness to human.