FIG. 7.

Survival rates of mice challenged with the wild-type and mutant strains of P. gingivalis. Construction of the tapA, tapB, tapC, and tapA-tapB-tapC mutants is described in Materials and Methods. Genetic manipulation did not affect the expression of the downstream or upstream gene (see Fig. S3 in the supplemental material). Female BALB/c mice were intradermally inoculated with P. gingivalis cells into the back (approximately 2 × 10¹¹ CFU), and then their survival was monitored daily for up to 9 days. The animal experiment, in which five mice were used for each bacterial strain, was performed three times. *, P < 0.05 versus the corresponding values for the wild-type littermates, as determined with the log-rank test.