化学療法のみで治癒した多発性ノカルジア脳膿瘍の1例

A Case of Brain Nocardiosis Successfully Treated with Minocycline

　要旨　60歳男性。ノカルジア膿胸の治療の既往がある患者が近医で脳膿瘍を発症。意識障害が出現したため，当科紹介入院となった。ノカルジア脳膿瘍として加療。外科的加療を行わず，ミノサイクリン長期投与により，後遺症なく治癒した。病理組織標本を用いたPCR法によりノカルジアの菌種を同定，その結果から薬剤感受性を調べ，それに基づいて適切な抗生剤治療を行ったことが，良好な予後に関与したと考えられる。

　A 60-year-old man with surgically treated nocardia pyothorax was referred to our hospital since he became drowsy. Brain MRI revealed multiple brain abscesses. His cerebrospinal fluid（CSF）showed increase in polymorphonuclear cells and decrease in glucose. Since he was allergic to sulfamethoxazole・trimethoprim, ceftriaxone and then minocycline were given. Minocycline resulted in dramatic improvement of neurological symptoms, MRI findings and CSF cell count. PCR analysis of 16S ribosomal DNA using his resected thoracic wall revealed that nocardia from his tissue was strain IFM0860. Strain IFM0860 nocardia was found to be sensitive to minocycline but not to sulfamethoxazole・trimethoprim and ceftriaxone. Intravenous administration of minocycline was followed by three-year per os administration of minocycline during which he had no recurrence of brain abscess. Thus, brain nocardiosis could be successfully treated with appropriate antibiotics. The lesson from the present case is that identification of the type of nocardia by PCR analysis of 16S ribosomal DNA could help accomplish tailor-made antibiotic therapy.