TABLE 3.
Distribution of SpeB protein activity among GAS isolated from invasive cases of varying severity
| Isolate source (n) | No. (%) of isolates with the following 28-kDa SpeB protein resulta:
|
Statisticsb
|
||||
|---|---|---|---|---|---|---|
| Concn (μg/ml) of:
|
Enzyme activity (101 FU) of:
|
Yates' corrected chi-square value | P | |||
| >100 | <100 | >350 | <350 | |||
| Nonsevere infection (29) | 25 (86) | 4 (14) | 25 (86) | 4 (14) | ||
| Severe infection (48) | 32 (66) | 16 (33) | 32 (66) | 16 (33) | 3.0 | 0.049 |
| STSS (17) | 10 (59) | 7 (41) | 10 (59) | 7 (41) | 3.0 | 0.042 |
| NF (20) | 13 (65) | 7 (35) | 13 (65) | 7 (35) | 2.0 | 0.081 |
| STSS + NF (11) | 9 (82) | 2 (18) | 9 (82) | 2 (18) | 0.02 | 0.531 |
a
SpeB production was determined by Western blot analysis as well as enzyme assay as described in Materials and Methods.
b
Association between lack of SpeB expression and disease severity was analyzed by Yates' corrected chi-square value, and significance was analyzed by Fisher's exact one-tailed test.