TABLE 2.
Invasion abilities of protease-positive and -mutant strains of GAS
| Strain | No. of streptococci (104 CFU/well) grown within A-549 cells reconstituted witha:
|
|||||
|---|---|---|---|---|---|---|
| None | SPE Bb | Heated SPE B | SPE B + E-64 (8 μM) | SPE B + E-64 (16 μM) | E-64 (16 μM) | |
| A-20 | 9.68 ± 0.14 | 12.6 ± 0.11 | 10.02 ± 0.37 | 10.2 ± 0.19 | 9.68 ± 0.30 | 9.88 ± 0.65 |
| SW507 | 4.87 ± 0.11 | 9.58 ± 0.29 | 5.32 ± 0.58 | 5.15 ± 0.17 | 4.38 ± 0.09 | 4.75 ± 0.39 |
| NZ131 | 10.79 ± 0.24 | 11.17 ± 0.39 | NDc | ND | ND | ND |
| SW510 | 4.43 ± 0.08 | 9.21 ± 0.29 | 5.40 ± 0.21 | 6.65 ± 0.81 | 6.40 ± 0.56 | 4.43 ± 0.05 |
a
Results are demonstrated as the number of intracellular bacteria ± standard error after 1.5 h of incubation.
b
The invasion assay was done with reconstituted purified SPE B.
c
ND, not done.