<prompt> Which of the following factor is mainly respon-sible for virulence in Streptococcus :CarbohydrateStreptokinaseStreptodornaseM protein  <response>: M ProteinIt is major virulence factor of group A Strep. pyogenes.It is hair like projection of cell wall.It is of 80 types basis of Griffith classification so immunity is type specific.M protein is also found in Group G streptococci.Remember :Carbohydrate is used as the basis of Lancefields classification.Streptokinase or fibrolysin and streptodornase or DNAse liquefy pus so used in enzymatic debridement 