streptococcus pyogenes descriptionstreptococcus pyogenes infectionbacteria streptococcus pyogenesbacitracin streptococcus pyogenesdefine streptococcus pyogenesstreptococcus pyogenes group as pyogenesstreptococcus pyogenes agarstreptokok pyogenesstreptococcus pyogenes skin infectionpseudomonas pyogenesstreptococcus pyogenes cdc