Table 2.

Vascular lesions identified in SKH1 mice inoculated with the GAS M3 wild-type strain or cysteine protease mutanta

Skin location and vascular lesion characterNo. positive/total at the following time (h) and treatment:
244872
PBS controlWild-type strainProtease mutantPBS controlWild-type strainProtease mutantPBS controlWild-type strainProtease mutant
Epidermis, infarction0/60/60/60/65/60/60/66/61/6b
Dermis
 Perivascular PMNs0/61/61/60/60/60/60/60/63/6
 Necrotizing vasculitis0/60/61/60/63/60/60/64/62/6c
 Thrombosis0/60/60/60/61/60/60/63/61/6
 Vascular congestion0/60/61/60/64/63/60/64/61/6
Subcutis
 Perivascular PMNs0/60/61/60/60/60/60/60/62/6
 Necrotizing vasculitis0/60/60/60/60/60/60/64/62/6
 Thrombosis0/60/60/60/60/61/60/63/62/6
 Vascular congestion0/60/60/60/65/63/60/61/62/6
  • a Mice were randomly assigned to be inoculated with the GAS M3 wild-type strain or cysteine protease mutant or with PBS. The statistical difference between vascular lesions in animals (days 2 and 3 combined) inoculated with the wild-type or cysteine protease mutant strain was calculated by using Fisher’s exact (two-tailed) test.

  • b P < 0.01.

  • c P < 0.05.