A 25-year-old man has fever, neck stiffness and petechiae. CSF shows gram-negative diplococci. Which organism is most likely?
Answer and explanation
Correct answer: A. Neisseria meningitidis
- Step 1: Gram-negative diplococci with petechiae indicate meningococcus. Answer: Neisseria meningitidis. Why not the others: Pneumococcus is a gram-positive diplococcus and the others do not appear as diplococci.
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