FIG 4.
F. tularensis O-antigen mutants in the waaY or waaL gene are able to disseminate to and replicate in the mouse liver and spleen. (A) BALB/c mice were intranasally infected with 300 CFU of F. tularensis Schu S4, 2.2 × 106 CFU of F. tularensis waaY::TrgTn, or 2.4 × 106 CFU of F. tularensis waaL::TrgTn. Homogenates of the lungs, liver, and spleen were plated from mice infected for 3, 6, 9, or 12 days to determine bacterial counts per organ. Horizontal lines represent the means of the organ counts for each strain at each time point. (B) From the initial inoculum to day 3 postinfection, fold growth of bacteria in the lung was calculated for Schu S4 and mutants. Fold growth was also calculated for mice infected with the mutants after day 3 postinfection. Comparison of fold growth after day 3 postinfection in mice infected with mutants could not be compared to that in Schu S4-infected mice because Schu S4-infected mice died before day 6 postinfection.