Intestinal colonization. Mice were orally inoculated with E1162 (black circles) or E1162Δesp (open circles). (A) Numbers of E1162 and E1162Δesp were determined in stool of mice at different time points after E. faecium inoculation. (B) After 10 days of colonization, numbers of E1162 and E1162Δesp were determined in small bowel, cecum and colon. Data are expressed as CFU per gram of stool/fecal contents and medians are shown for 7 mice per group.