Table 4.

Virulence of K56-2 and pvdA mutants in a chronic respiratory infection modela

StrainDay 7 p.i.Day 28 p.i.
CFU/ml/lung% PathologyCFU/ml/lung% Pathology
Expt 1
 K56-24.3 × 106 ± 4.1 × 106 51.5 ± 32.93.3 × 105 ± 5.1 × 105 22.0 ± 9.8
 I1173.1 × 102 ± 2.1 × 102b 26.2 ± 7.74.0 × 101 ± 6.1 × 101b 5.0 ± 3.1c
Expt 2
 K56-21.5 × 106 ± 2.5 × 106 40.5 ± 4.22.4 × 105 ± 4.5 × 105 39.0 ± 4.7
 K56pvdA::tp7.2 × 103 ± 1.3 × 104d 15.2 ± 5.0d 0d 13.5 ± 3.5d
  • a Values represent the means ± the standard deviations of four animals.

  • b I117 is significantly different than K56-2 (P < 0.05) by the one-tailed Mann-Whitney ttest.

  • c I117 is significantly different than K56-2 (P < 0.05) by the unpaired t test.

  • d K56pvdA::tp is significantly different than K56-2 (P < 0.05) by ANOVA.