Shiga toxin-producing strains of enterohemorrhagic Escherichia coli (EHEC) are a class of pathogenic E. coli responsible for numerous food- and water-borne outbreaks causing a range of illness in humans, from non-bloody diarrhea to hemorrhagic colitis or hemolytic uremic syndrome (HUS). Strains of EHEC O157:H7, colonize the intestine and produce multiple determinants which cause the pathology associated with the disease. My laboratory is interested to understand what are the mechanisms used by EHEC strains to adhere and colonize the intestinal epithelia. Our major goal is the characterization of novel adhesins and the regulatory network controlling their expression during intestinal colonization.
The second main project of our lab is defining the importance of bacterial surface structures in the pathogenesis of Adherent-Invasive Escherichia coli (AIEC) isolates and their role in the development of an inflammatory response. We are determining whether certain serotypes of AIEC strains are associated with inflammation, as observed in patients suffering from Crohn’s disease and Ulcerative colitis. Furthermore, we have recently completed the genome sequence of our prototype AIEC strain and now we are establishing whether specific virulence factors expressed by AIEC strains are associated with chronic inflammation using in vitro and in vivo models of infection.
Finally, my laboratory has initiated a new area of investigation focusing in the pathogenic mechanisms of Burkholderia mallei and the development of candidates for vaccine testing. Currently, we are characterizing the type III secretion system found in this pathogen using in vitro approaches, and testing multiple virulence factors as vaccine candidates to protect against aerosol infection.