Shigella flexneri causes shigellosis, the second leading cause of diarrheal deaths worldwide. The pathogen invades colonic epithelial cells using a type III secretion system (T3SS) that delivers effector proteins to remodel host actin cytoskeleton. Following invasion, S. flexneri acquires actin-based motility and spreads cell to cell, driving epithelial destruction and bloody diarrhea. These intracellular infection processes have been investigated primarily using exponentially growing planktonic