Which bacteria form pus in clusters like grapes?

• A. Streptococci
• B. Diplococci
• C. Bacilli
• D. Staphylococci

Answer: (D)

The clue lies in how the bacteria arrange themselves after dividing. Staphylococci form grape-like clusters because the cocci divide in multiple planes and pile into irregular, clumped groups resembles a bunch of grapes. This clustering is a hallmark that helps distinguish them from other cocci. Streptococci divide in a single plane and line up in chains, so they look like strings of beads. Diplococci appear as pairs due to division in two planes with a characteristic pairing. Bacilli are rod-shaped and do not form those grape-like clusters. Clinically, Staphylococcus aureus is a common cause of pus, which aligns with this clustered arrangement.