Adhesion and colonization of enterohemorrhagic Escherichia coli O157:H7 in cecum of mice

Microbiol Immunol. 2003;47(2):125-32. doi: 10.1111/j.1348-0421.2003.tb02795.x.


Infectious diseases due to enterohemorrhagic Escherichia coli (EHEC) are characterized by diarrhea, hemorrhagic colitis and hemolytic uremic syndrome. The adherence of EHEC on intestinal epithelial cells is a first step for developing these diseases. In the present study, we examined whether EHEC O157:H7 adhere to intestinal epithelial cells of mice and cause F-actin accumulation in the epithelial cells following the intragastric inoculation of the pathogen. Fecal shedding of the EHEC O157:H7 strain was observed in ICR mice up to 3 weeks. Fecal shedding periods of the type III secretion system-related gene (espA and sepL) deletion mutants were clearly shorter than that of the wild-type EHEC O157:H7 strain. The EHEC O157:H7 colonies were found on the epithelial surfaces of the ceca in association with F-actin accumulation beneath the attached bacteria.

MeSH terms

  • Actins / metabolism
  • Animals
  • Bacterial Adhesion*
  • Cecum / microbiology*
  • Epithelial Cells / microbiology
  • Escherichia coli Infections / microbiology
  • Escherichia coli O157 / pathogenicity*
  • Escherichia coli O157 / physiology*
  • Escherichia coli Proteins / genetics
  • Feces / microbiology
  • Female
  • Gene Deletion
  • HeLa Cells
  • Hemolytic-Uremic Syndrome / microbiology
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mice, Inbred ICR
  • Microscopy, Confocal


  • Actins
  • Escherichia coli Proteins
  • EspA protein, E coli
  • SepL protein, E coli