TABLE 3.
Weight loss and lesion development in mice inoculated subcutaneously with GASa
| Experiment (inoculum) | Strain or description | Mean 24-h weight gain ± SD | No. with lesions/no. inoculatedb | No. with necrosis/no. with lesionsb |
|---|---|---|---|---|
| I (3 × 105) | MGAS166 (wt) | 1.3 ± 0.4 | 0/6 | 0/0 |
| csrR::Tn916 (muc5) | 0.6 ± 0.5 | 1/6 | 0/1 | |
| ΔcsrR csrS | −1.7 ± 1.6 | 4/6 | 3/4 | |
| ΔcsrR csrS ΔhasAB | −0.1 ± 0.9 | 5/6 | 1/5 | |
| II (2 × 106) | Controlc | 0.6 ± 0.07 | 0/6 | 0/0 |
| MGAS166 (wt) | −0.4 ± 1.2 | 0/6 | 0/0 | |
| csrR::Tn916 (muc5) | −3.7 ± 0.8 | 6/6 | 6/6 | |
| ΔcsrR csrS | −4.3 ± 0.6 | 6/6 | 6/6 | |
| ΔcsrR csrS ΔhasAB | −3.4 ± 0.8 | 6/6 | 5/6 | |
| III (2 × 105) | Controld | 0.5 ± 0.6 | 0/8 | 0/0 |
| MGAS166 (wt) | 0.9 ± 0.4 | 0/6 | 0/0 | |
| csrR::Tn916 (muc5) | 0.2 ± 1.4 | 0/7 | 0/0 | |
| ΔcsrR csrS | −2.1 ± 1.7 | 3/6 | 3/3 | |
| ΔcsrR csrS ΔhasAB | 0.4 ± 1.3 | 1/6 | 0/1 | |
| IV (4 × 106) | Controlc | 1.2 ± 0.4 | 0/6 | 0/0 |
| MGAS166 (wt) | 1.1 ± 0.3 | 4/12 | 0/4 | |
| csrR::Tn916 (muc5) | −3.1 ± 0.6 | 6/6 | 6/6 | |
| csrR::Tn916 (muc7) | −3.3 ± 0.6 | 6/6 | 6/6 | |
| ΔcsrR csrS | −3.7 ± 0.4 | 12/12 | 12/12 | |
| ΔcsrR csrS ΔhasAB | −1.6 ± 0.9 | 6/6 | 4/6 |
a
All bacteria were grown in Todd-Hewitt broth at 37°C to mid-exponential phase (A600 = 0.6 to 0.7). Culture conditions were as follows: experiment I, shaken and aerated; experiment II, shaken and aerated; experiment III, static and capped; experiment IV, static and capped. wt, wild type.
b
Counts taken at 72 h.
c
Control mice were uninoculated mice from the same cohort.
d
Control mice received subcutaneous injections of THY broth.