微生物学の課題

Microbiology Problem

　6歳の白人の女の子が，腹痛と頸部の強直を訴えて入院した．彼女の体温38.8℃，血圧80／56，脈拍118，呼吸数26で，首を曲げさせるのに強い抵抗があった．ケルニッヒ及びブルジンスキー徴候が陽性，ババンスキー反応は正常で，初めの臨床的印象は髄膜炎ということだった．入院時の検査結果を表Iに示す．

　この（表Iに示した），細胞または細菌の全くいない透明な髄液という予期せぬ所見は，臨床診断に影響し，これらの所見から早期無菌髄膜炎と診断された．髄液はチョコレート寒天培地に培養されただけであった．18時間後，検査室は，その髄液から培養されたのは形態学的にナイセリア髄膜炎菌に似ているグラム陰性の双球菌だと報告した．グラム標本は図1に示す．治療は直ちに対症療法からampicillinの使用へと変えられ，静脈内点滴法で注射された．

A 6-year-old Caucasian^*1 female was admitted to the hospital with complaints of abdominal pain and neck stiffness. Her temperature was 38.8C. Her blood pressure was 80/56; pulse rate, 118; respiratory rate, 26. The patient vigorously resisted any attempt to flex her neck. The Kernig and Brudzinski signs were positive. The Babinski response was normal. The initial clinical impression^*2 was that the patient had meningitis. See Table I for results of admission laboratory tests^*3. The unexpected finding^*4 of a clear spinal fluid with no cells or bacteria influenced the clinical diagnosis. In view of these findings, early aseptic meningitis was diagnosed. The spinal fluid was cultured on a chocolate agar plate only. After eighteen hours, the laboratory reported a gram-negative diplococcus morphologically resembling Neisseria meningitidis cultured from the spinal fluid. The gram smear is seen in Figure 1. Therapy was immediately switched from symptomatic and supportive^*5 to use of ampicillin^*6, administered by intravenous drip.