Review Question - QID 215141

A 12-year-old boy presents to the emergency department with fever, headache, and lethargy. He rouses to voice but otherwise demonstrates little spontaneous activity. His mother states that he has been hospitalized for a “brain infection” 3 times in the past that was treated with ceftriaxone. His postnatal history was otherwise normal. He has no other medical history and is only taking acetaminophen. The patient’s temperature is 103.2°F (39.6°C), blood pressure is 90/60 mmHg, pulse is 112/min, and respirations are 28/min. Physical exam reveals a lethargic adolescent boy in a recumbent position. Flexion of his neck causes flexion at the hips and knees. A lumbar puncture is performed and a Gram stain of the cerebrospinal fluid (CSF) reveals gram-negative diplococci. Which of the following is the most likely underlying etiology of the patient’s condition?