FIGURE 3.

Monitoring of wild-type S. Enteritidis and S. Enteritidis fimH::kan mutant infections in mice by whole-body bioluminescence imaging (BLI) and validation of type 1 fimbriae as a virulence factor of S. Enteritidis in mice. BALB/c mice (7 per group) were inoculated per os with 10⁴ Salmonella CFUs (A), 10⁵ Salmonella CFUs (B) and 10⁷ Salmonella CFUs (C) The presence of bioluminescence signals was monitored in animals every morning for 21 days after inoculation and intensity of bioluminescence emission is represented as a pseudocolor image. The animals were sacrificed immediately when the bioluminescent signal was observed. Infection-free-times, defined as bioluminescence-free-times were obtained using the method of Kaplan and Meier, and significance of differences was determined by the Gehan–Breslow–Wilcoxon test. Mice infected with 10⁴ (D), 10⁵ (E), and 10⁷ (F) S. Enteritidis fimH::kan mutant had significantly (P < 0.05) shorter infection-free times in comparison to animals inoculated with wild-type S. Enteritidis.