TABLE 4.
Lung and blood bacterial cell counts after nasal challenge with different pneumococcal serotypesa
| Group | Response to serotype
|
|||||||
|---|---|---|---|---|---|---|---|---|
| 3
|
6B
|
14
|
23F
|
|||||
| Lung (CFU/g) | Blood (CFU/ml) | Lung (CFU/g) | Blood (CFU/ml) | Lung (CFU/g) | Blood (CFU/ml) | Lung (CFU/g) | Blood (CFU/ml) | |
| Adult mice immunized with: | ||||||||
| L. lactis PppA+ | 3.8 ± 0.3** | <1.5** | 3.1 ± 0.2** | <1.5** | <1.5** | <1.5** | <1.5** | <1.5** |
| L. lactis PppA | 6.1 ± 0.4 | 4.2 ± 0.3 | 5.6 ± 0.5* | 3.9 ± 0.5 | 5.7 ± 0.4* | 4.1 ± 0.4 | 4.1 ± 0.3 | 3.6 ± 0.4 |
| Control | 6.9 ± 0.3 | 4.8 ± 0.2 | 6.3 ± 0.3 | 4.0 ± 0.2 | 6.1 ± 0.5 | 4.1 ± 0.7 | 4.3 ± 0.4 | 3.8 ± 0.5 |
| Young mice immunized with: | ||||||||
| L. lactis PppA+ | 4.2 ± 0.2** | <1.5** | 3.3 ± 0.5** | <1.5** | <1.5** | <1.5** | <1.5** | <1.5** |
| L. lactis PppA | 7.9 ± 0.4 | 4.6 ± 0.3 | 6.9 ± 0.3* | 4.4 ± 0.7 | 5.9 ± 0.6* | 4.3 ± 0.5 | 5.5 ± 0.5* | 4.1 ± 0.7 |
| Control | 8.3 ± 0.2 | 5.2 ± 0.2 | 7.5 ± 0.3 | 4.5 ± 0.3 | 6.9 ± 0.4 | 4.7 ± 0.4 | 6.2 ± 0.3 | 4.4 ± 0.2 |
a
Adult and young mice were immunized with recombinant L. lactis (pVE-PppA) with L. lactis PppA+ or without L. lactis PppA previous to induction with nisin. Results are expressed as log CFU/g of lung or log CFU/ml of blood. The lower limits of bacterial detection were 1.5 log CFU/g of lung and 1.5 log CFU/ml of blood. Asterisks represent significant differences from the respective control groups: *, P < 0.05; **, P < 0.01.