system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
True about protein A of staph aureus ?
assistant
The correct answer is  Ans. is 'b' i.e., Binds to Fc pa of IgG Protein 'A' binds to Fc terminal of IgG (IgG 1, 2 & 4 but not IgG3) and prevents opsonophagocytosis by PMNs.It is a B-cell mitogen. It is chemotactic, anti-complementory and antiphagocytic.