Figure 6.

Presence of NK cells in spleen of mice 5 days post infection with the wild type S. Enteritidis (wt) or attenuated ΔSPI2, rfaL or lon mutants as determined in the animal infection 2. n.i. - non-infected mice. The NK cells depletion was not specific for the ΔSPI2 mutant but was a general indicator of the mutant's virulence or avirulence. Since there were only 3 animals per group and greater variation was observed among the mice infected with the wild type S. Enteritidis, none of the differences in this experiment reached statistical significance.