Which bacteria is responsible for Erysipelas (a superficial skin/soft tissue infection with raised, well-demarcated borders)?

Erysipelas is a superficial cutaneous infection characterized by bright red, raised, sharply demarcated plaques with a 'peau d'orange' appearance. It is caused by Group A beta-hemolytic Streptococcus (Streptococcus pyogenes), though Group B, C, and G streptococci can also be responsible. The raised, well-demarcated border distinguishes it from cellulitis. Treatment is penicillin.