日本新生児成育医学会雑誌　第32巻　第1号　98 ～ 102頁（2020年）

日本新生児成育医学会雑誌　32(1)：98-102；2020　

受付日：2019．03．22

受理日：2019．05．21

Helicobacter cinaedi による新生児髄膜炎の1 例

A Case of Neonatal Meningitis Caused by Helicobacter cinaedi

長野赤十字病院　小児科

Department of Pediatrics, Nagano Red Cross Hospital

森川愛美・平林佳奈枝・赤川大介・石田岳史

Manami MORIKAWA，Kanae HIRABAYASHI，Daisuke AKAGAWA，Takefumi ISHIDA

Key Words：Helicobacter cinaedi，neonatal meningitis，gram-negative spiral bacterium

在胎39 週0 日，出生体重3,150g の男児。日齢16 に39℃台の発熱を主訴に当科を受診した。髄液検査では細胞数 3,410/μL と多核球優位に増加し，髄液糖/ 血糖比は低下していた。細菌性髄膜炎を疑いAmpicillin とCefotaxime で治療を開始した。入院時の髄液グラム染色は陰性で，3 日間の髄液培養でも発育は認めなかった。しかし，血液培養開始7 日目に好気ボトルからグラム陰性らせん菌が検出された。血液培養の結果を受け，残りの髄液検体を使用し微好気湿潤環境で改めて培養検査を実施したところ，培養開始4 日目に同様の菌が発育した。質量分析法と遺伝子解析法を用いた菌種同定によりH. cinaedi と同定された。3 週間の抗菌薬治療を行い，後遺症なく退院した。　H. cinaedi は発育が緩徐であり培養検査での検出に時間を要するという特徴がある。新生児感染症の原因菌としては稀だが，起因菌不明の髄膜炎や敗血症症例では，このような菌の可能性も考慮し，適切な培養条件と培養期間を設ける必要がある。

We report a case of neonatal meningitis caused by Helicobacter cinaedi （H. cinaedi）. The patient was a 16-day-old boy who was born via normal vaginal delivery at a gestational age of 39 weeks；his birth weight was 3,150g. He was admitted to our hospital because of fever. The cerebrospinal fluid（ CSF） findings revealed an elevated white cell count of 3,410 cells per microliter（ 73.6％ neutrophils） and decreased CSF/blood glucose ratio；however, gram stain showed no bacteria. Intravenous antibiotic therapy with ampicillin and cefotaxime was started immediately after collecting culture samples. His fever subsided on the third day of hospitalization. On the seventh day, aerobic blood culture revealed gram-negative spiral bacteria, later identified as H. cinaedi via mass spectrometry and 16s ribosomal RNA analysis. Although the bacteria were not detected from a 3-day routine CSF culture, they were isolated from a second CSF culture under microaerobic conditions and high humidity on day 4 of incubation. The patient was administered antibiotics for 3 weeks and discharged in good clinical condition.
H. cinaedi is known to have a relatively prolonged incubation time under microaerobic conditions with high humidity. The culture test should be performed with adequate duration and conditions to reach the detection limit as far as possible. It is important to remember that H. cinaedi can be the causative pathogen for neonatal infections.