Penn R L, Normand R, Klotz S A
Department of Medicine, Veterans Administration Medical Center, Shreveport, LA 71101-4295.
Infect Control Hosp Epidemiol. 1988 Nov;9(11):501-3. doi: 10.1086/645760.
Although gram-negative meningitis is rare in our hospital, between July, 1982 and July, 1983 clusters of cerebrospinal fluid (CSF) smears were reported positive for gram-negative bacilli. Fourteen specimens were obtained by diagnostic lumbar punctures, and one was obtained during a myelogram. No CSF cultures were positive, and a diagnosis of factitious meningitis was eventually established for each patient. Nonviable gram-negative bacilli were found in 6.7% of manometers, and 23.3% to 90% of the specimen tubes tested from the same lots of commercial lumbar puncture trays. It was estimated that there were between 44 and 333 organisms per specimen tube. Two lots of the commercial myelogram trays yielded nonviable gram-negative bacilli from 50% of the specimen tubes and 33.3% of the manometers tested. Retrospective review of laboratory records for 1982 and 1983 revealed 23 total CSF smears positive for gram-negative bacilli. No CSF grew gram-negative bacilli, and chart reviews confirmed a diagnosis of factitious meningitis in each case. In addition to the clusters of false-positive smears, this had occurred sporadically in both years. The problem did not recur after separate sterile tubes were provided for CSF collection. Physicians and laboratories should be aware that nonviable contaminants in commercial products may be a source of false-positive CSF gram-stained smears.
尽管革兰氏阴性菌脑膜炎在我院较为罕见，但在1982年7月至1983年7月期间，有多例脑脊液涂片报告革兰氏阴性杆菌呈阳性。通过诊断性腰椎穿刺获取了14份标本，在脊髓造影检查时获取了1份标本。脑脊液培养均为阴性，最终确诊每位患者为假性脑膜炎。在6.7%的压力计以及来自同一批次商用腰椎穿刺托盘的23.3%至90%的标本管中发现了无活力的革兰氏阴性杆菌。据估计，每个标本管中有44至333个微生物。两批次商用脊髓造影托盘在50%的标本管以及33.3%的检测压力计中产生了无活力的革兰氏阴性杆菌。回顾1982年和1983年的实验室记录，共有23例脑脊液涂片革兰氏阴性杆菌呈阳性。脑脊液培养均未生长出革兰氏阴性杆菌，病历审查证实每例均为假性脑膜炎。除了出现多例假阳性涂片外，这两年中也有散发病例。在提供单独的无菌管用于脑脊液采集后，该问题未再出现。医生和实验室应意识到商用产品中的无活力污染物可能是脑脊液革兰氏染色涂片假阳性的一个来源。
