Identification of occult Fusobacterium nucleatum central nervous system infection by use of PCR-electrospray ionization mass spectrometry.

Anaerobic bacteria are often difficult to detect, especially after the initiation of antibiotics. We describe the application of PCR-electrospray ionization mass spectrometry (PCR/ESI-MS) using a sample of cerebrospinal fluid to identify an anaerobic Gram-negative bacillus, Fusobacterium nucleatum, in a patient with "culture-negative" meningitis and cerebral abscesses.