A laboratory needs to differentiate a Gram-positive coccus isolated from pus into the genus Staphylococcus or Streptococcus. Which single rapid biochemical test provides this differentiation?

• A Oxidase test
• B Urease test
• C Coagulase test
• D Catalase test ✓

Explanation

Staphylococci possess catalase and produce visible bubbles when mixed with hydrogen peroxide, while streptococci lack this enzyme. This single test separates the two genera before further identification. Coagulase is only a species-level test within Staphylococcus and cannot identify streptococci, making it the tempting distractor that fails at genus level.

Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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