[Case of subdural empyema caused by Porphyromonas and Fusobacterium identified by 16S ribosomal RNA gene sequence analysis].

A 24-year-old woman presented subdural empyema developing from sinusitis caused by Porphyromonas and Fusobacterium infection. She experienced fever and progressive headache with gradually worsening symptoms. Neurological examination revealed drowsiness and neck stiffness. A CSF examination detected pleocytosis and a low glucose level. Gadolinium-enhanced T1-weighted images from brain MRI showed thickening enhancement at the leptomeninges in the left frontal to temporal lobes and interhemispheric fissure with edema. Based on the diagnosis of bacterial meningoencephalitis and subdural empyema developing from sinusitis primary to odontogenic infection, she received antibacterial chemotherapy with meropenem hydrate and vancomycin hydrochloride, after which motor aphasia and consciousness disturbance occurred. No bacteria were isolated from a trans-sphenoidal biopsy specimen and CSF culture. Molecular typing also was performed by sequencing the 16S ribosomal RNA intergenic spacer region, and Porphyromonas and Fusobacterium were identified. She was given cephalosporin and metronidazol, after which her neurological symptoms and signs gradually lessened. Physicians need to be aware that patients may develop subdural empyema subsequent to sinusitis associated with Porphyromonas and Fusobacterium infection and that amplification and sequence analysis of partial bacterial 16S ribosomal RNA gene should be examined when no bacteria is identified by culture.