All are true about streptococcus except:
Mucoid colonies are due to production of capsule of hyaluronic acid not due to M-protein. Growth characteristic of strep. Pyogenes:
On blood agar virulent stains form matt or mucoid colones while avirulent from glossy colonies.
M, T, R are proteins found on outer part of cell wall and forms the basis of Griffith classification.
M protein – acts as virulence factor and antibody against it are protective.
T and R protein – No relation to virulence
M-protein is responsible for production of mucoid colonies
M- protein is responsible for virulence
Mucoid colonies are virulent
No resistance to penicillin has been reported