S. pyogenes' skin infection diagnostics
S. pyogenes cultured on Blood Agar should show beta-hemolysis. B-hemolytic colonies can be further identified as S. pyogenes by the results of negative catalase (hydrogen peroxide) test, positive L-pyrrolidonyl arylamidase (PYR) reaction (1) and sensitivity to Bacitracin (2). See https://www.inkling.com/read/medical-microbiology-murray-rosenthal-pfaller-7th/chapter-19/streptococcus-pyogenes

PCR may also be used: http://www.sciencedirect.com/science/article/pii/S0923250805000215