The patient was a 4-year-old female with a fraternal twin. Her medical history was unremarkable and her vaccination status was appropriate for her age. During the previous week, she and her twin and two younger siblings had had upper respiratory tract infections with nasal congestion. On the night prior to admission, she developed fever and left ear pain. She was examined and found to have a bulging left eardrum consistent with otitis media. She was begun on oral amoxicillin/clavulanic acid. Early the next afternoon, she continued to have fever and was irritable. Later that afternoon, she also complained of a headache and neck pain and was brought to the emergency department. On physical examination, she was lethargic, listless, and had a stiff neck. There were no focal neurologic findings, but it was noted that she had a rash on her right cheek which the physician thought might be an early stage ofa petechial rash. He per- formed a lumbar puncture. The fluid was with a white blood cell (wBC) cloudy count of 6,750/ul (normal, 0 to 3 cellsul, 95% being neutrophils, and 189 red blood cells/ul. Her cerebrospinal (CSF protein level was 170 mg/dl (normal, 15 to 45 mg/d) and CSF glucose level was 25 mg/dl (normal, 50 to 75 mg/dl). AGram stain of the CSF is shown in Fig. 1. The culture ofthe organism recov- ered from CSF is shown in Fig. 2. of note, her serum imm agl lev- unoglobulin els agG, IgA, IgM) were normal. 1. What pathologic process is going on in this child? What organism do you think is infecting this patient? 2. What is the significance of her having otitis media in the development of her infection? What is the major virulence factor(s) produced by this organism? When this o does not produce one of these vir- ulence factors, what types of infection does it typically cause? 3. What is the significance of her developing a petechial rash? What organism that causes bacterial meningitis frequently has this type of Flyer 1 Figure 2