This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Streptococci, Subject name: Microbiology
Early detection of Streptococcus pyogenes is by? 
Select and explain. 
A. Bacitracin, B. Oxaciliicin, C. Methidllin, D. Optochin
A: Bacitracin
Answer: A: Bacitracin 
Explanation: ANSWER: (A) BacitracinREF: Jawetz Microbiology, 24th Ed, Ch. 15See previous questionStreptococcus pyogenes are PYR-positive (hydrolysis of L-pyrrolidonyl-2-naphthylamide) and usually are susceptible to bacitracin.