Case History: Case J

A 2-month-old girl was well until 3 days prior to admission, when she developed a runny nose, fever, vomiting and irritibility. At the emergency department, a generalized seizure occurred. The anterior fontanelle was bulging and tense. Exam showed nuchal rigidity. CSF analysis showed elevated protein, decreased glucose, thousands of WBCs, 90% neutrophils. What is the most likely diagnosis?