Table 1.
Staphylococcal surface proteins are required to establish acute infections in mice
| S. aureus strain | cfu injected | Mortality, % |
|---|---|---|
| Experiment 1 | ||
| Newman (wt) | 1.25 × 108 | 90 |
| Newman (wt) | 1.25 × 107 | 90 |
| Newman (wt) | 1.25 × 106 | 0 |
| SKM3 (srtA−) | 1.35 × 108 | 20 |
| SKM3 (srtA−) | 1.35 × 107 | 0 |
| SKM3 (srtA−) | 1.35 × 106 | 0 |
| Experiment 2 | ||
| Newman (wt) | 7.0 × 107 | 100 |
| Newman (wt) | 7.0 × 106 | 40 |
| Newman (wt) | 7.0 × 105 | 0 |
| SKM3 (srtA−) | 1.1 × 108 | 40 |
| SKM3 (srtA−) | 1.1 × 107 | 0 |
| SKM3 (srtA−) | 1.1 × 106 | 0 |
S. aureus strains Newman (wild-type) and the isogenic sortase mutant SKM3 were grown overnight in TSB supplemented with 5% sheep's blood at 37°C. The cultures were diluted 1∶10 in fresh medium and incubated with shaking for 5 h. Staphylococci were diluted into 5% hog gastric mucin, and 0.5 ml was injected i.p. into 10 CD1 mice per dilution. Animals were observed for 72 h, and moribund mice were euthanized. Average LD50 Newman 7.2 × 106 (Exp. 1), 7.58 × 106 (Exp. 2) and SKM3 1.8 × 108 (Exp. 1), 1.2 × 108 (Exp. 2) (P < 0.05).