TABLE 4.
Cysteine protease activities in culture supernatants of GAS isolated from invasive cases of varying severity
| Isolate source (n) | Enzyme activity (101 FU)a
|
Pb | |
|---|---|---|---|
| Mean ± SD | Median | ||
| Nonsevere infection (29) | 1,072 ± 437 | 1,108 | |
| Severe infection (48) | 722 ± 527 | 877 | 0.004 |
| STSS (17) | 564 ± 459 | 704 | 0.001 |
| NF (20) | 810 ± 582 | 1,147 | 0.079 |
| STSS + NF (11) | 804 ± 509 | 1,056 | 0.107 |
a
The enzyme activity of SpeB was determined by a fluorescent enzyme assay described in Materials and Methods.
b
Differences between the enzyme activities of SpeB produced by isolates from nonsevere cases and isolates from various subgroups of severe cases were evaluated by the Student t test.