FIG. 4.
Survival of BALB/c mice after intranasal infection with wzz mutants. Survival of mice infected with wild-type PA103 and the wzz mutants is illustrated. Doses used for infection were as follows: PA103, 6.7 × 105; wzz1, 6.2 × 105; wzz2, 5.2 × 105; double mutant (DM), 4.9 × 105. Curves were plotted using the Kaplan-Meier method, and curve comparisons were done using the log-rank test. The PA103 and wzz2 survival curves were each significantly different from the DM curve (P < 0.05). No other statistically significant differences were detected.