<prompt> Streptococcus pyogenes shows pathogenicity by all except?M proteinPyrotoxinPiliStreptolysin O  <response>: Ans. is c i.e., Pili Virulence factors of str. pyogenes Str. pyogenes forms several exotoxins and enzymes which contribute to its virulence, but M protein is the most impoant of these. 