FIG 4.

Colonization and bacterial excretion in C57 and BALB/c mice. Eleven BALB/c mice and eight C57 mice were euthanized at day 3 p.i. to determine colonization in the cecum, small intestine, and large intestine. The stools of 7 BALB/c and 7 C57 mice were removed from the large intestine to determine the bacterial excretion. The graphs represent the CFU of O157:H7/cm of intestinal segment or the CFU of O157:H7/g of feces versus the bacterial dose administered as CFU × 10¹²/kg. (A to C) Colonization of the small intestine (A), large intestine (B), and cecum (C) from infected BALB/c mice. (D to F) Colonization of the small intestine (D), large intestine (E), and cecum (F) from infected C57 mice. (G and H) Bacterial excretion by infected BALB/c mice (G) and infected C57 mice (H). Data were analyzed by Spearman’s correlation test. All associations (log CFU/cm intestinal segment or log CFU/g feces versus CFU × 10¹²/kg) show positive correlations: *, P < 0.05; **, P < 0.01; ***, P < 0.001.