This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci), Subject name: Microbiology
[{'content': 'Virulence factor of group A beta hemolytic streptococci:- \nSelect and explain. \nA. Protein M, B. Protein T, C. Protein R, D. Lipotechoic acid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Option 1 2 3 Cell wall antigens: Inner thick peptidoglycan layer (confers cell wall rigidity, induces inflammatory response and has thrombolytic activity) C-carbohydrate antigen: Present as middle layer and is group specific Outer layer of protein (M, T, R) and lipoteichoic acid (helps in adhesion) M protein - Major virulence factor of S pyogenes Option 4 Outer layer of lipoteichoic acid (helps in adhesion)', 'role': 'assistant'}]