A 17-year-old boy comes to the physician because of a 2-day history of fatigue, fever, and non-productive cough. Temperature is 101 F. Physical examination shows pale conjunctivae. X-ray of the chest shows bilateral interstitial infiltrates. A sample of blood drawn for testing agglutinates spontaneously en route to the laboratory. Which of the following is the most likely causal organism?
Chlamydia pneumoniae
Legionella pneumophila
Mycoplasma pneumoniae
Staph aureus
Strep pneumoniae
