Regulation of waaH by PhoB during P i Starvation Promotes Biofilm Formation by Escherichia coli O157:H7

Abstract

Enterohemorrhagic Escherichia coli O157:H7 is a human pathogen that causes bloody diarrhea that can result in renal failure. Outside of mammalian hosts, E. coli O157:H7 survives for extended periods of time in nutrient-poor environments, likely as part of biofilms. In E. coli K-12, the levels of free extracellular P i affect biofilm formation; however, it was unknown whether P i influences biofilm formation by E. coli O157:H7. Our results show that upon P i starvation, PhoB activates waaH expression, which favors biofilm formation by E. coli O157:H7. These findings suggest that WaaH is a target for controlling biofilm formation. Altogether, our work demonstrates how adaptation to P i starvation allows E. coli O157:H7 to occupy different ecological niches.