FIG. 4.
CIqPCR analysis of 18 strains in Nramp1+/+ and Nramp1−/− mice. Groups of five mice (Nramp1+/+ and Nramp1−/− 129SvJ) were infected with equal mixtures of 17 strains, containing mutations in the genes indicated, as well as the wild-type control. The total number of infecting bacteria was about 104. The spleens were extracted at day 5 postinfection, and persistence levels of Salmonella strains in the spleen were compared via qPCR using the formula shown. CIqPCR values were averaged from the five mice in each group and shown in white (Nramp1+/+) and gray (Nramp1−/−). Strains with CIqPCR values greater than 1 indicate that they outcompeted the wild-type strain; strains with values less than 1 indicate that they were outcompeted by the wild-type strain. A Student t test was applied for statistical analysis of the results, and strains showing significant changes between Nramp1+/+ and Nramp1−/− mice (P < 0.05) are labeled with an asterisk.