TABLE 1.
Selection for catalase production in S. aureus in the nasal epithelium
| Established population or control | Mixed inoculum
|
Established S. pneumoniae inoculum
|
||
|---|---|---|---|---|
| Selection rate (mean ± SEM)a | P valueb | Selection rate (mean ± SEM) | P value | |
| PBS | 0.48 ± 0.83 | 0.583 | ||
| TIGR4 | 0.48 ± 0.42 | 0.296 | 5.52 ± 0.59 | 0.006 |
| SpxB | 1.63 ± 0.39 | 0.006 | 3.40 ± 0.64 | 0.002 |
a
KatA+ relative to KatA−.
b
Two-tailed probability from the t distribution of rejecting by chance the null hypothesis that the selection rate constant equals 0, indicating equal fitness for the catalase-producing (Newman) and catalase-deficient (KatA) strains.