TABLE 2.

Phenotypic characteristics of mutants

GASHemolytic units of the following toxin/ml of cultureHyaluronic acid (fg/CFU)Streptokinase (U/ml of culture)Protease (mm)cMultiplicity index in human blood from donord
SLOaSLSbAB
TBCHTBCH
Wild type>1,0000013616.1 ± 3.49.8 ± 0.78.8 ± 1.321.824.1
sloΔ1 mutant00013616.9 ± 1.19.5 ± 0.68.6 ± 1.021.737.8
sagBΔ1 mutant>1,00000018.4 ± 2.910.0 ± 0.76.6 ± 1.545.347.1
sloΔ1 sagBΔ1 mutant000016.0 ± 2.09.9 ± 0.76.4 ± 1.927.932.3
  • a Precipitated from cell-free supernatants of pH-controlled late-log-phase cultures. Tested in the presence of trypan blue (TB) and cholesterol (CH).

  • b Cell-bound activity determined for cells from 50-ml early-stationary-phase cultures. Tested as described for SLO.

  • c Diameters of cleared zones on casein plates, determined as described by Wheeler et al. (61).

  • d The multiplicity index is the output CFU after 3 h of rotation in fresh human blood divided by the input CFU at time zero. In these assays, an M protein-deficient mutant of strain Manfredo had an index of <1.0.