Table 2.
Bacteremia after i.p. challenge of human fH transgenic infant rats
| Expt (age of rats) | Serum human fHa | H44/76 strain | Challenge dose (CFU/rat) | No. of rats | Bacteremiab |
|||
|---|---|---|---|---|---|---|---|---|
| Time after challenge (h) | No. positive (%) | GM CFU/ml | 95% CI | |||||
| 1 (6 to 7 days) | Positive | Wild type | 560 | 18 | 6 | 18 (100) | 394 | 178–873 |
| Negative | Wild type | 560 | 7 | 18 | 0 (0)A | <10 | NA | |
| Positive | Wild type | 560 | 19 | 19 (100)B | 120,000 | 22,000–680,000 | ||
| 2 (5 to 7 days) | Negative | Wild type | 2,800 | 2 | 18 | 0 (0) | <10 | NA |
| Positive | Wild type | 2,800 | 10 | 10 (100) | 3,614A | 217–60,000 | ||
| Positive | ΔfHbp mutant | 2,800 | 9 | 9 (100) | 3,311B | 129–85,000 | ||
| 3 (8 to 10 days) | Negative | Wild type | 5,800 | 15 | 6 | 1 (7) | <10A | <10 |
| Positive | Wild type | 5,800 | 17 | 17 (100) | 2,065B | 893–4,775 | ||
| Positive | ΔfHbp mutant | 4,900 | 20 | 20 (100) | 612C | 325–1,153 | ||
| Positive | ΔfHbp ΔNspA mutant | 3,100 | 17 | 17 (100) | 849D | 422–1,710 | ||
| 4 (8 to 9 days) | Positive | ΔfHbp ΔNspA mutant | 1,800 | 16 | 6 | 16 (100) | 532A | 213–1,326 |
| Positive | ΔfHbp ΔNspA Δlst mutant | 2,000 | 15 | 0 (0) | <10 | NA | ||
| Positive | Δlst mutant | 3,100 | 16 | 15 (94) | 105B | 41–271 | ||
Transgenic littermates negative for human fH (<12 μg/ml) or positive for human fH (79 to 831 μg/ml) were used.
GM, geometric mean; CI, confidence interval. NA, not applicable (all animals in the group had negative blood cultures). P values were determined as follows by comparing various values (indicated by superscript capital letters for each experiment). Experiment 1: A versus B, P <0.0001 (Fisher exact test). Experiment 2: A versus B, P > 0.9 (Student t test). Experiment 3: A, one animal had bacteremia of 80 CFU/ml; B, C, and D, P <0.05 (three-way ANOVA), with pairwise comparisons for B versus C, P < 0.02; B versus D, P = 0.09; and C versus D, P = 0.5 (Student t test). Experiment 4: A versus B, P = 0.014.