Which of the following is a characteristic of Staphylococcus aureus?

• A. Obligate intracellular pathogen
• B. Gram-positive cocci arranged in clusters
• C. Gram-negative diplococci
• D. Motile, spore-forming rods

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the morphology and staining characteristics of Staphylococcus aureus. It is important to recall that S. aureus is a type of bacteria classified by its shape and Gram stain reaction.
2. Step 2: Recall that Staphylococcus aureus is Gram-positive, meaning it retains the crystal violet stain and appears purple under a microscope after Gram staining.
3. Step 3: Recognize that the term 'cocci' refers to spherical-shaped bacteria, and 'arranged in clusters' means these cocci group together in grape-like clusters, which is typical for Staphylococcus species.
4. Step 4: Compare the options: 'Obligate intracellular pathogen' refers to bacteria that must live inside host cells, which is not true for S. aureus; 'Gram-negative diplococci' describes a different group of bacteria (e.g., Neisseria); 'Motile, spore-forming rods' describes bacteria like Bacillus species, not S. aureus.
5. Step 5: Conclude that the characteristic matching Staphylococcus aureus is 'Gram-positive cocci arranged in clusters' based on its morphology and staining properties.