This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Streptococcus is called as flesh eating bacteria due to its? 
Select and explain. 
A. Streptolysin A, B. Streptolysin 0, C. Pyrogenic exotoxin, D. Hyaluronidase
C: Pyrogenic exotoxin
Answer: C: Pyrogenic exotoxin 
Explanation: Ans. is 'c' i.e., Pyrogenic exotoxin Streptococcal necrotising fascitis is caused by streptococcus pyogenes M types 1 and 3 strains forming pyrogenic exotoxin A.These strains have earned notoriety under the name "Flesh eating bacteria" and cause extensive necrosis of subcutaneous and muscular tissue and adjucent fascia which may be associated with severe systemic illness.