1. Staphylococcus aureus and Streptococcus pyogenes are implicated as the causative agents of least three skin diseases. What are they? 2. How are S. aureus and S. pyogenes phenotypically similar? How are they different? 3. What diagnostic tests are used to distinguish between S. aureus and S. pyogenes? How does each organism react to each test? 4. What would be the outcome of a catalase test if it was performed on S. aureus? On S.pyogenes?