Pathogenesis of Escherichia coli O157:H7 Strain 86-24 Following Oral Infection of BALB/c Mice with an Intact Commensal Flora
NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD
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Escherichia coli 0 157H7 is a food-borne pathogen that can cause hemorrhagic colitis and. occasionally. hemolytic uremic syndrome, a sequela of infection that can result in renal failure and death. Here we sought to model the pathogenesis of orally-administered E. coli 0157H7 in BALBc mice with an intact intestinal nora. First. we defined the optimal dose that permitted sustained fecal shedding of E. coli 0157H7 over 7 days -109 colony forming units. Next. we monitored the load of E. coli 0157H7 in intestinal sections over time and observed that the cecum was consistently the tissue with the highest E. coli 0157 H7 recovery. We then followed the expression of two key E. coli 0 157H7 virulence factors. the adhesin intimin and Shiga toxin type 2, and detected both proteins early in infection when bacterial burdens were highest. Additionally, we noted that during infection, animals lost weight and - 30 died. Moribund animals also exhibited elevated levels of blood urea nitrogen. and. on necropsy, showed evidence of renal tubular damage. We conclude that conventional mice inoculated orally with high doses of E. coli 0 157H7 can be used to model both intestinal colonization and subsequent development of certain extraintestinal manifestations of E. coli 0157H7 disease.
- Medicine and Medical Research