A 7-year-old boy is brought to the clinic by his mother because of persistent discharge from his right ear for the past 2 months. She reports that the discharge is foul-smelling and sometimes blood-tinged. The child denies fever but occasionally complains of difficulty hearing in that ear. He had multiple episodes of acute otitis media in early childhood. Otoscopic examination reveals a perforated tympanic membrane with purulent discharge. There is no mastoid tenderness or swelling. What is the most likely causative organism in this patient?
