All are true about streptococcus Except

Mucoid colonies are due to the production of the capsule of hyaluronic acid not due to M-protein. Growth characteristic of Strep. pyogenes: On blood agar, virulent stains form matt or mucoid colonies while avirulent from glossy colonies. M, T, R are proteins found on the outer pa of the cell wall and forms the basis of Griffith classification. M protein - acts as virulence factor and antibody against it is protective. T and R protein - No relation to virulence Ref : 208