FIG 3.

AC enzyme activity of CyaA alone supports lung infection by B. pertussis. (A) Infection of the mouse lungs. Four-week-old Swiss CD-1 mice were challenged intranasally with 10⁵ CFU of the parental AC⁺ Hly⁺ strain or the AC⁻ Hly⁺ and AC⁺ Hly⁻ mutants. The mean values and standard deviations from six mice per time point were plotted (except for day 12, which is a mean value from only three mice). The results represent the average of values obtained in two experiments. (B) Survival rates of 4-week-old mice infected with 1 × 10⁸ CFU of the WT and mutant B. pertussis strains. (C) Survival rates at the increased inoculation dose of 6 × 10⁸ CFU. Mortality was monitored for 10 days postinfection. The results were reproduced in at least 3 experiments using 6 to 8 mice per challenged group per challenge dose.