Explain MRSA and a major virulence factor.

• A. MRSA is Staphylococcus aureus resistant to methicillin due to mecA-encoded PBP2a; virulence factors include Protein A.
• B. MRSA is Methicillin-Sensitive Staphylococcus aureus; virulence factor is catalase.
• C. MRSA is a virus; virulence factor is reverse transcriptase.
• D. MRSA is a fungus; virulence factor is ergosterol.

Answer: (A)