This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'An 11-year-old child presented with sore throat since 3 days, which medium is used to culture the throat swab \nSelect and explain. \nA. Blood agar, B. LJ medium, C. Stewa medium, D. Chocolate agar', 'role': 'user'}, {'content': "Answer: A \nExplanation: Streptococcus pyogenes is the most common cause of sore throat. To rule out streptococcus pyogenes infection, the throat swab should be cultured on blood agar. On blood agar, after incubation for 24 hours the colonies are small, circular, semi-transparent, low convex discs with an area of clear hemolysis around them. Virulent strains on fresh isolation from lesions produce a matt colony while avirulent strains produce glossy colonies. Strains with well-marked capsules produce mucoid colonies. Crystal violet blood agar is the selective medium and Pikes medium is the transpo media for Streptococcus pyogenes Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 217", 'role': 'assistant'}]