C-DI-GMP SIGNALING IN ESCHERICHIA COLI 0157:H7 BIOFILM FORMATION AND GASTROINTESTINAL TRACT COLONIZATION OF BEEF CATTLE

(WYO-448-10)

E. coli O157:H7 induces huge losses to the beef industry and is a threat to consumer safety. Fecal shedding of E. coli O157:H7 from beef cattle is the major source of this pathogen and biofilms on facility surfaces in processing plants provide a constant source of pathogens, including E. coli O157:H7. Up to now, our knowledge about the mechanisms regulating E. coli O157:H7 biofilm formation and gut colonization is very limited. The c-di-GMP molecule is a cytoplasmic second messenger that mediates a myriad of cellular processes. Based on its roles in regulating motility, biofilm formation and virulence gene expression in other pathogenic microorganisms, c-di-GMP signaling is likely involved in E. coli O157:H7 biofilm formation in food processing plants and in cattle gut colonization. Through studies proposed in this project, we will assess the role of c-di-GMP signaling in E. coli O157:H7 colonization and biofilm formation. As an extension of such studies, we will try to develop specific strategies to control E. coli O157:H7 colonization in gastro-intestine tract by targeting identified molecular mediators. Because c-di-GMP signaling is a universal signaling molecule and is involved in biofilm formation and virulence gene expression, knowledge obtained through these studies will have wide applications. These applications will not only be limited to E. coli O157:H7, but will deepen our understanding of food-borne pathogens and their pathogenesis in general, facilitating our efforts to provide consumers with safer foods.

USDA CRIS Project Information Link: 0221020