Table 7.
In vivo inhibitory activity of two compounds alone and combinations against clinical S. pneumoniae.
| Strains | Antimicrobial agent | Dose (mg/kg/d) | Mean log CFU at site of infectiona | |||||
|---|---|---|---|---|---|---|---|---|
| NW (P-value) | Lung (P-value) | |||||||
| 24 h | 48 h | 72 h | 24 h | 48 h | 72 h | |||
| 19A | Control | 7.29 | 5.97 | 6.01 | 4.85 | 6.12 | 6.29 | |
| PEN | 0.29 | 6.44 | 5.88 | 5.34 | 4.8 | 4.5 | 4.89 | |
| Deoxyshikonin | 0.45 | 6.08 (0.026)b | 2.76 (0.005)b | 3 (0.011)b | 1 | 2.39 (0.0001)b | 1.05 (0.04)b | |
| Dodecylgallate | 0.57 | 5.91 (0.021)b | 5.28 | 3.62 (0.033)b | 1 | 3 | 2.82 | |
| Deoxyshikonin+PEN | 5.82 | 4.2 | 3.36 | 1.61 | 4.15 | 3.43 | ||
| Dodecylgallate+PEN | 6.15 | 4.8 (0.04)c | 3.35 | 1.61 | 2.25 (0.017)c | 1.53 | ||
| 19F | Control | 6.72 | 6.27 | 7.09 | 2.82 | 7.57 | 4.95 | |
| PEN | 0.16 | 6.21 | 2.1 | 6.12 | 1 | 2.58 | 3.22 | |
| Deoxyshikonin | 0.45 | 3.30 | 4.6 (0.0002)b | 5.52 (<0.0001)b | 1 (<0.0001)b | 1 (0.001)b | 2.5 (<0.0001)b | |
| Dodecylgallate | 0.57 | 2.16 | 5.55 | 5.82 (<0.0001)b | 3.9 (0.0001)b | 3 (0.006)b | 2.8 (<0.0001)b | |
| Deoxyshikonin+PEN | 6.27 | 3.1 (0.049)c | 5.34 (0.02)c | 3.57 | 1 | 2.39 | ||
| Dodecylgallate+PEN | 6.33 | 1.95 | 4.26 (0.004)c | 7.5 | 3.45 | 2.51 | ||
a
The mice were intranasally infected clinical S. pneumoniae 19A (CMCC31689) and 19F (CMCC31693) (1.5 × 108 CFU) in each group and received intraperitoneal injections of drugs three times a day for 3 days. The numbers of bacteria in nasopharynx and lung were determined at 24, 48, and 72 h.
b
Differences between treated groups and controls were analyzed. P < 0.05 was considered significant.
c
Differences between treated groups versus Penicillin. P < 0.05 was considered significant.