Bacterial shapeshifting: Escherichia coli differentiation during urinary tract infection

Urinary tract infections are caused primarily by uropathogenic strains of Escherichia coli (UPEC). UPEC is known to transition through a series of distinct infection stages, displaying reversible morphological differentiation along the way. Initial steps involve bladder invasion by rod-shaped bacteria to establish intracellular bacterial communities consisting of coccoid cells. Subsequently, during exit from infected cells, UPEC regain their rod-shape and in some cases even form large filaments. Using a flow-chamber based tissue culture infection model we have studied UPEC gene expression during the course of infection. Our results reveal a novel SOS-independent mechanism of reversible cell-division control.