An unimmunized, 2-year-old boy presents with drooling from the mouth, elevated temperature, and enlarged tonsils. During attempts at intubation, no gray-white membrane is observed but the epiglottis appears "beefy" red and edematous. Which of the following is the most likely organism?
Haemophilus haemolyticus Haemophilus influenzae Klebsiella pneumoniae Mycoplasma pneumoniae