FIG 9.

Colonization of mouse organs by various E. faecalis strains. Standardized inocula of 8 × 10⁸ CFU of the maltotetraose-positive E. faecalis strain JH2-2 and the malT mutant (A), the tpx mutant (B), and the mdxF mutant (C) derived from it were intraperitoneally injected into Swiss white mice. After 24 h (malT and mdxF mutant) or 72 h (tpx mutant), the survival rate was determined for each strain by bacterial counts in kidneys, liver, and spleen (CFU per gram of tissue) and in the peritoneum (CFU per milliliter of washing fluid). The experiments were carried out with 5 mice per group. The experiment with the mdxF mutant was performed twice, and the results obtained with the 10 mice are shown (C). The numbers obtained for each individual mouse (dots) are presented as log₁₀. The results are expressed in CFU per gram (for the organs) and as CFU per milliliter (for the peritoneal wash); mean values are presented as horizontal bars. To compare the results obtained for two different groups, we used the Mann-Whitney test. The calculated P values of <0.05 (*) and <0.005 (**) reflect the overall difference of the CFU values determined in kidney or liver, respectively, between the groups of mice infected with the mdxF mutant and the ones infected with the wild-type strain.