Gram Positive Cocci
All are true about streptococcus pyogenes except:
|A||M protein is responsible for production of mucoid colonies|
|B||M protein is responsible for virulence|
|C||Mucoid colonies are virulent|
|D||No resistance to penicillin has been reported|
a. Mucoid colonies are due to production of hyaluronic acid capsule. When the capsule becomes wrinkled, the colony morphology becomes Matt
b. Virulent strains of S.pyogenes produce mucoid or matt colonies.
c. Both capsule and M protein are important virulence factors as both are antiphagocytic. No resistance to penicillin has been reported.