Bacteroides meningitis complicating chronic mastoiditis.

A 70-year-old man with a history of chronic middle and external ear suppuration presenting with acute meningitis due to Bacteroides uniformis is described. Anaerobic organisms including Bacteroides species were cultured from the affected external auditory meatus. Administration of metronidazole led to complete clinical recovery and a cholesteatoma was subsequently surgically evacuated. Chronic suppuration in the middle ear and paranasal sinuses is the commonest primary cause of cerebral abscess and in this setting meningitis is associated with a particularly high mortality. The major role of anaerobic sepsis in otolaryngological practice is well established. Metronidazole is the chemotherapeutic agent of choice.