[Direct Gram staining of blood culture sample enabled the early diagnosis of brain abscess due to Listeria monocytogenes].

A 58 year old woman had a long history of immunocompromised state. Since age 28 she had multiple endocrine neoplasm type 2A: her thyroid gland and bilateral adrenal glands were removed because of pheochromocytoma and thyroid medullary carcinoma. Corticosteroid and levothyroxine were supplemented. At age 57 she was afflicted with systemic lupus erythematodes and nephrotic syndrome. Prednisolone therapy was started. Two months later she developed fever, lethergy, headache and left hemiparesis. MRI revealed multiple ring-enhancing lesions in the right cerebrum. CSF was negative for microorganisms. Blood culture hemolysed after 24 hours. Direct gram staining of the blood culture sample revealed gram-positive short rods without spore, suggested listeria. This enabled prompt initiation of high dose penicillin therapy before the official report of listseria infection. Neurological abnormality including left hemiparesis disappeared completely within one month. Enhancement of abscess wall decreased every month, but it persisted for five months despite continuous intravenous penicillin therapy. Listeria monocytogenes is well-recognized as an opportunistic pathogen. It requires prolonged therapy with antibiotics, since it is the intracellular organism. Monitoring of the brain abscess wall by the enhanced MRI is useful to determine the completion of therapy. Since listerial contamination is common among raw meat and unpasteurized milk, immunocompromised patients should be alarmed not to eat uncooked food products.