re pt oc oc cal ▁py ro gen ic ▁ex ot ox in ▁B ), ▁a ▁c yst e ine ▁prote ase ▁that ▁acts ▁as ▁a ▁vir ul ence ▁factor . ▁In ▁the ▁absence ▁of ▁this ▁path way , ▁bio film ▁formation ▁is ▁en hanced , ▁possibly ▁due ▁to ▁the ▁lack ▁of ▁the ▁prote ase ▁de grad ing ▁ph er om ones ▁or ▁other ▁R gg 2 / 3 ▁path way ▁counter act ing ▁effects . ▁ ▁D ise ase ▁▁ ▁S . ▁py ogen es ▁is ▁the ▁cause ▁of ▁many ▁human ▁dise ases , ▁r anging ▁from ▁m ild ▁super f icial ▁skin ▁in fe ctions ▁to ▁life - th re aten ing ▁system ic ▁dise ases . ▁In fe ctions ▁typically ▁begin ▁in ▁the ▁thro at ▁or ▁skin . ▁The ▁most ▁striking ▁sign ▁is ▁a ▁st raw berry - like ▁r ash . ▁Ex amples ▁of ▁m ild ▁S . ▁py ogen es ▁in fe ctions ▁include ▁ph ary ng itis ▁( st rep ▁thro at ) ▁and ▁local ized ▁skin ▁in fection ▁( imp et igo ). ▁ ▁E rys ip el as ▁and ▁cell ul itis ▁are ▁character ized ▁by ▁multiplication ▁and ▁later al ▁spread ▁of ▁S . ▁py ogen es ▁in ▁deep ▁layers ▁of ▁the ▁skin . ▁S . ▁py ogen es ▁invasion ▁and ▁multiplication ▁in ▁the ▁fas cia ▁can ▁lead ▁to ▁ne c rot izing ▁fas ci itis , ▁a ▁life - th re aten ing ▁condition ▁requiring ▁surg ery . ▁ ▁The ▁b acter ium ▁is