Virulence factor of the group A beta-hemolytic streptococcus is
High-Yield Explanation
The virulence factors of group A streptococcus or Streptococcus pyogenes: 1. Capsule 2. Carbohydrate antigen 3. Protein antigen M, T, R proteins 4. Pili M protein - acts as virulence factor by inhibiting phagocytosis. Heat and acid stable but susceptible to tryptic digestion. Antibody to M proteins promote phagocytosis of cocci and is protective. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 213