Fig. 4.

Impaired virulence of the pgdA mutant in vivo. (A and B) BALB/c and C57/BL6J mice were challenged by i.v. injection with the parental strain EGDe and its pgdA mutant with a sublethal dose (5 × 10³ CFU per mouse). After 72 h, mice were killed, and bacterial counts in the liver (A) and the spleen (B) were determined. (C–G) Transgenic human E-cadherin mice were used as model for the oral route of infection, and colonization of several organs was followed after 3, 24, 48, and 72 h after challenge. Interestingly, the pgdA mutant was particularly vulnerable to persistence in the intestinal lumen as assayed by bacterial counts per grams of feces (C). Survival was more robust in the intestine (D) and the mesenteric lymph nodes (E) where colonization was particularly impaired after 72 h. The mutant was impaired in the survival of the liver (F) and spleen (G) at all time points as in the IV model shown in A and B.